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aria-controls="toc-History-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle History subsection</span> </button> <ul id="toc-History-sublist" class="vector-toc-list"> <li id="toc-Antiquity_and_early_middle_ages" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Antiquity_and_early_middle_ages"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Antiquity and early middle ages</span> </div> </a> <ul id="toc-Antiquity_and_early_middle_ages-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Geotechnical_investigation_and_design" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Geotechnical_investigation_and_design"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Geotechnical investigation and design</span> </div> </a> <button aria-controls="toc-Geotechnical_investigation_and_design-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Geotechnical investigation and design subsection</span> </button> <ul id="toc-Geotechnical_investigation_and_design-sublist" class="vector-toc-list"> <li id="toc-Choice_of_tunnels_versus_bridges" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Choice_of_tunnels_versus_bridges"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.1</span> <span>Choice of tunnels versus bridges</span> </div> </a> <ul id="toc-Choice_of_tunnels_versus_bridges-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Project_planning_and_cost_estimates" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Project_planning_and_cost_estimates"> <div class="vector-toc-text"> <span class="vector-toc-numb">3.2</span> <span>Project planning and cost estimates</span> </div> </a> <ul id="toc-Project_planning_and_cost_estimates-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Construction" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Construction"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Construction</span> </div> </a> <button aria-controls="toc-Construction-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Construction subsection</span> </button> <ul id="toc-Construction-sublist" class="vector-toc-list"> <li id="toc-Cut-and-cover" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Cut-and-cover"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.1</span> <span>Cut-and-cover</span> </div> </a> <ul id="toc-Cut-and-cover-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Boring_machines" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Boring_machines"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.2</span> <span>Boring machines</span> </div> </a> <ul id="toc-Boring_machines-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Shafts" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Shafts"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.3</span> <span>Shafts</span> </div> </a> <ul id="toc-Shafts-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Sprayed_concrete_techniques" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Sprayed_concrete_techniques"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.4</span> <span>Sprayed concrete techniques</span> </div> </a> <ul id="toc-Sprayed_concrete_techniques-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Pipe_jacking" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Pipe_jacking"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.5</span> <span>Pipe jacking</span> </div> </a> <ul id="toc-Pipe_jacking-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Box_jacking" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Box_jacking"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.6</span> <span>Box jacking</span> </div> </a> <ul id="toc-Box_jacking-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Underwater_tunnels" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Underwater_tunnels"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.7</span> <span>Underwater tunnels</span> </div> </a> <ul id="toc-Underwater_tunnels-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Temporary_way" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Temporary_way"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.8</span> <span>Temporary way</span> </div> </a> <ul id="toc-Temporary_way-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Enlargement" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Enlargement"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.9</span> <span>Enlargement</span> </div> </a> <ul id="toc-Enlargement-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Open_building_pit" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Open_building_pit"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.10</span> <span>Open building pit</span> </div> </a> <ul id="toc-Open_building_pit-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Other_construction_methods" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Other_construction_methods"> <div class="vector-toc-text"> <span class="vector-toc-numb">4.11</span> <span>Other construction methods</span> </div> </a> <ul id="toc-Other_construction_methods-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Variant_tunnel_types" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Variant_tunnel_types"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Variant tunnel types</span> </div> </a> <button aria-controls="toc-Variant_tunnel_types-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Variant tunnel types subsection</span> </button> <ul id="toc-Variant_tunnel_types-sublist" class="vector-toc-list"> <li id="toc-Double-deck_and_multipurpose_tunnels" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Double-deck_and_multipurpose_tunnels"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.1</span> <span>Double-deck and multipurpose tunnels</span> </div> </a> <ul id="toc-Double-deck_and_multipurpose_tunnels-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Covered_passageways" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Covered_passageways"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.2</span> <span>Covered passageways</span> </div> </a> <ul id="toc-Covered_passageways-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Underpass" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Underpass"> <div class="vector-toc-text"> <span class="vector-toc-numb">5.3</span> <span>Underpass</span> </div> </a> <ul id="toc-Underpass-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Safety_and_security" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Safety_and_security"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Safety and security</span> </div> </a> <ul id="toc-Safety_and_security-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Examples" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Examples"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>Examples</span> </div> </a> <button aria-controls="toc-Examples-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Examples subsection</span> </button> <ul id="toc-Examples-sublist" class="vector-toc-list"> <li id="toc-In_history" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#In_history"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.1</span> <span>In history</span> </div> </a> <ul id="toc-In_history-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Longest" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Longest"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.2</span> <span>Longest</span> </div> </a> <ul id="toc-Longest-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Notable" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Notable"> <div class="vector-toc-text"> <span class="vector-toc-numb">7.3</span> <span>Notable</span> </div> </a> <ul id="toc-Notable-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Mining" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Mining"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>Mining</span> </div> </a> <ul id="toc-Mining-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Military_use" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Military_use"> <div class="vector-toc-text"> <span class="vector-toc-numb">9</span> <span>Military use</span> </div> </a> <ul id="toc-Military_use-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Secret_tunnels" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Secret_tunnels"> <div class="vector-toc-text"> <span class="vector-toc-numb">10</span> <span>Secret tunnels</span> </div> </a> <ul id="toc-Secret_tunnels-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Natural_tunnels" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Natural_tunnels"> <div class="vector-toc-text"> <span class="vector-toc-numb">11</span> <span>Natural tunnels</span> </div> </a> <ul id="toc-Natural_tunnels-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Major_accidents" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Major_accidents"> <div class="vector-toc-text"> <span class="vector-toc-numb">12</span> <span>Major accidents</span> </div> </a> <ul id="toc-Major_accidents-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">13</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">14</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Bibliography" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#Bibliography"> <div class="vector-toc-text"> <span class="vector-toc-numb">15</span> <span>Bibliography</span> </div> </a> <ul id="toc-Bibliography-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">16</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Tunnel</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 86 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-86" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">86 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Tonnel" title="Tonnel – Afrikaans" lang="af" hreflang="af" data-title="Tonnel" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-als mw-list-item"><a href="https://als.wikipedia.org/wiki/Tunnel" title="Tunnel – Alemannic" lang="gsw" hreflang="gsw" data-title="Tunnel" data-language-autonym="Alemannisch" data-language-local-name="Alemannic" class="interlanguage-link-target"><span>Alemannisch</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D9%86%D9%81%D9%82" title="نفق – Arabic" lang="ar" hreflang="ar" data-title="نفق" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-an mw-list-item"><a href="https://an.wikipedia.org/wiki/T%C3%BAnel" title="Túnel – Aragonese" lang="an" hreflang="an" data-title="Túnel" data-language-autonym="Aragonés" data-language-local-name="Aragonese" class="interlanguage-link-target"><span>Aragonés</span></a></li><li class="interlanguage-link interwiki-ast mw-list-item"><a href="https://ast.wikipedia.org/wiki/T%C3%BAnel" title="Túnel – Asturian" lang="ast" hreflang="ast" data-title="Túnel" data-language-autonym="Asturianu" data-language-local-name="Asturian" class="interlanguage-link-target"><span>Asturianu</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%B8%E0%A7%81%E0%A6%A1%E0%A6%BC%E0%A6%99%E0%A7%8D%E0%A6%97" title="সুড়ঙ্গ – Bangla" lang="bn" hreflang="bn" data-title="সুড়ঙ্গ" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D1%8D%D0%BB%D1%8C" title="Тунэль – Belarusian" lang="be" hreflang="be" data-title="Тунэль" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D1%8D%D0%BB%D1%8C" title="Тунэль – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="Тунэль" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bh mw-list-item"><a href="https://bh.wikipedia.org/wiki/%E0%A4%B8%E0%A5%81%E0%A4%B0%E0%A4%82%E0%A4%97" title="सुरंग – Bhojpuri" lang="bh" hreflang="bh" data-title="सुरंग" data-language-autonym="भोजपुरी" data-language-local-name="Bhojpuri" class="interlanguage-link-target"><span>भोजपुरी</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D0%B5%D0%BB" title="Тунел – Bulgarian" lang="bg" hreflang="bg" data-title="Тунел" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Tunel" title="Tunel – Bosnian" lang="bs" hreflang="bs" data-title="Tunel" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-br mw-list-item"><a href="https://br.wikipedia.org/wiki/Riboul" title="Riboul – Breton" lang="br" hreflang="br" data-title="Riboul" data-language-autonym="Brezhoneg" data-language-local-name="Breton" class="interlanguage-link-target"><span>Brezhoneg</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/T%C3%BAnel" title="Túnel – Catalan" lang="ca" hreflang="ca" data-title="Túnel" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Tunel" title="Tunel – Czech" lang="cs" hreflang="cs" data-title="Tunel" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Tunnel" title="Tunnel – Danish" lang="da" hreflang="da" data-title="Tunnel" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Tunnel" title="Tunnel – German" lang="de" hreflang="de" data-title="Tunnel" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Tunnel" title="Tunnel – Estonian" lang="et" hreflang="et" data-title="Tunnel" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%A3%CE%AE%CF%81%CE%B1%CE%B3%CE%B3%CE%B1" title="Σήραγγα – Greek" lang="el" hreflang="el" data-title="Σήραγγα" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/T%C3%BAnel" title="Túnel – Spanish" lang="es" hreflang="es" data-title="Túnel" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Tunelo" title="Tunelo – Esperanto" lang="eo" hreflang="eo" data-title="Tunelo" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Tunel" title="Tunel – Basque" lang="eu" hreflang="eu" data-title="Tunel" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%AA%D9%88%D9%86%D9%84" title="تونل – Persian" lang="fa" hreflang="fa" data-title="تونل" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Tunnel" title="Tunnel – French" lang="fr" hreflang="fr" data-title="Tunnel" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Toll%C3%A1n" title="Tollán – Irish" lang="ga" hreflang="ga" data-title="Tollán" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/T%C3%BAnel" title="Túnel – Galician" lang="gl" hreflang="gl" data-title="Túnel" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%ED%84%B0%EB%84%90" title="터널 – Korean" lang="ko" hreflang="ko" data-title="터널" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%B9%D5%B8%D6%82%D5%B6%D5%A5%D5%AC" title="Թունել – Armenian" lang="hy" hreflang="hy" data-title="Թունել" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%B8%E0%A5%81%E0%A4%B0%E0%A4%82%E0%A4%97" title="सुरंग – Hindi" lang="hi" hreflang="hi" data-title="सुरंग" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Tunel" title="Tunel – Croatian" lang="hr" hreflang="hr" data-title="Tunel" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-io mw-list-item"><a href="https://io.wikipedia.org/wiki/Tunelo" title="Tunelo – Ido" lang="io" hreflang="io" data-title="Tunelo" data-language-autonym="Ido" data-language-local-name="Ido" class="interlanguage-link-target"><span>Ido</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Terowongan" title="Terowongan – Indonesian" lang="id" hreflang="id" data-title="Terowongan" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-ia mw-list-item"><a href="https://ia.wikipedia.org/wiki/Tunnel" title="Tunnel – Interlingua" lang="ia" hreflang="ia" data-title="Tunnel" data-language-autonym="Interlingua" data-language-local-name="Interlingua" class="interlanguage-link-target"><span>Interlingua</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/Jar%C3%B0g%C3%B6ng" title="Jarðgöng – Icelandic" lang="is" hreflang="is" data-title="Jarðgöng" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Galleria_(ingegneria)" title="Galleria (ingegneria) – Italian" lang="it" hreflang="it" data-title="Galleria (ingegneria)" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%9E%D7%A0%D7%94%D7%A8%D7%94" title="מנהרה – Hebrew" lang="he" hreflang="he" data-title="מנהרה" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-kn mw-list-item"><a href="https://kn.wikipedia.org/wiki/%E0%B2%B8%E0%B3%81%E0%B2%B0%E0%B2%82%E0%B2%97" title="ಸುರಂಗ – Kannada" lang="kn" hreflang="kn" data-title="ಸುರಂಗ" data-language-autonym="ಕನ್ನಡ" data-language-local-name="Kannada" class="interlanguage-link-target"><span>ಕನ್ನಡ</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%92%E1%83%95%E1%83%98%E1%83%A0%E1%83%90%E1%83%91%E1%83%98" title="გვირაბი – Georgian" lang="ka" hreflang="ka" data-title="გვირაბი" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D0%BD%D0%B5%D0%BB%D1%8C" title="Туннель – Kazakh" lang="kk" hreflang="kk" data-title="Туннель" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/Tin%C3%A8l" title="Tinèl – Haitian Creole" lang="ht" hreflang="ht" data-title="Tinèl" data-language-autonym="Kreyòl ayisyen" data-language-local-name="Haitian Creole" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-ky mw-list-item"><a href="https://ky.wikipedia.org/wiki/%D0%A2%D0%BE%D0%BD%D0%BD%D0%B5%D0%BB%D1%8C" title="Тоннель – Kyrgyz" lang="ky" hreflang="ky" data-title="Тоннель" data-language-autonym="Кыргызча" data-language-local-name="Kyrgyz" class="interlanguage-link-target"><span>Кыргызча</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Cuniculus_(aedificium)" title="Cuniculus (aedificium) – Latin" lang="la" hreflang="la" data-title="Cuniculus (aedificium)" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Tunelis" title="Tunelis – Latvian" lang="lv" hreflang="lv" data-title="Tunelis" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/Tunnel" title="Tunnel – Luxembourgish" lang="lb" hreflang="lb" data-title="Tunnel" data-language-autonym="Lëtzebuergesch" data-language-local-name="Luxembourgish" class="interlanguage-link-target"><span>Lëtzebuergesch</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Tunelis" title="Tunelis – Lithuanian" lang="lt" hreflang="lt" data-title="Tunelis" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Alag%C3%BAt" title="Alagút – Hungarian" lang="hu" hreflang="hu" data-title="Alagút" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D0%B5%D0%BB" title="Тунел – Macedonian" lang="mk" hreflang="mk" data-title="Тунел" data-language-autonym="Македонски" data-language-local-name="Macedonian" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%A4%E0%B5%81%E0%B4%B0%E0%B4%99%E0%B5%8D%E0%B4%95%E0%B4%82" title="തുരങ്കം – Malayalam" lang="ml" hreflang="ml" data-title="തുരങ്കം" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mr mw-list-item"><a href="https://mr.wikipedia.org/wiki/%E0%A4%AD%E0%A5%81%E0%A4%AF%E0%A4%BE%E0%A4%B0" title="भुयार – Marathi" lang="mr" hreflang="mr" data-title="भुयार" data-language-autonym="मराठी" data-language-local-name="Marathi" class="interlanguage-link-target"><span>मराठी</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Terowong" title="Terowong – Malay" lang="ms" hreflang="ms" data-title="Terowong" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D0%BD%D0%B5%D0%BB" title="Туннел – Mongolian" lang="mn" hreflang="mn" data-title="Туннел" data-language-autonym="Монгол" data-language-local-name="Mongolian" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-my mw-list-item"><a href="https://my.wikipedia.org/wiki/%E1%80%A5%E1%80%99%E1%80%84%E1%80%BA" title="ဥမင် – Burmese" lang="my" hreflang="my" data-title="ဥမင်" data-language-autonym="မြန်မာဘာသာ" data-language-local-name="Burmese" class="interlanguage-link-target"><span>မြန်မာဘာသာ</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Tunnel" title="Tunnel – Dutch" lang="nl" hreflang="nl" data-title="Tunnel" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ne mw-list-item"><a href="https://ne.wikipedia.org/wiki/%E0%A4%B8%E0%A5%81%E0%A4%B0%E0%A5%81%E0%A4%99" title="सुरुङ – Nepali" lang="ne" hreflang="ne" data-title="सुरुङ" data-language-autonym="नेपाली" data-language-local-name="Nepali" class="interlanguage-link-target"><span>नेपाली</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E3%83%88%E3%83%B3%E3%83%8D%E3%83%AB" title="トンネル – Japanese" lang="ja" hreflang="ja" data-title="トンネル" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Tunnel" title="Tunnel – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Tunnel" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Tunnel" title="Tunnel – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Tunnel" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Tun%C3%A8l" title="Tunèl – Occitan" lang="oc" hreflang="oc" data-title="Tunèl" data-language-autonym="Occitan" data-language-local-name="Occitan" class="interlanguage-link-target"><span>Occitan</span></a></li><li class="interlanguage-link interwiki-mhr mw-list-item"><a href="https://mhr.wikipedia.org/wiki/%D0%A2%D0%BE%D0%BD%D0%BD%D0%B5%D0%BB%D1%8C" title="Тоннель – Eastern Mari" lang="mhr" hreflang="mhr" data-title="Тоннель" data-language-autonym="Олык марий" data-language-local-name="Eastern Mari" class="interlanguage-link-target"><span>Олык марий</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Tunnel" title="Tunnel – Uzbek" lang="uz" hreflang="uz" data-title="Tunnel" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-pnb mw-list-item"><a href="https://pnb.wikipedia.org/wiki/%D8%B3%D8%B1%D9%86%DA%AF" title="سرنگ – Western Punjabi" lang="pnb" hreflang="pnb" data-title="سرنگ" data-language-autonym="پنجابی" data-language-local-name="Western Punjabi" class="interlanguage-link-target"><span>پنجابی</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Tunel_(budownictwo)" title="Tunel (budownictwo) – Polish" lang="pl" hreflang="pl" data-title="Tunel (budownictwo)" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/T%C3%BAnel" title="Túnel – Portuguese" lang="pt" hreflang="pt" data-title="Túnel" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Tunel" title="Tunel – Romanian" lang="ro" hreflang="ro" data-title="Tunel" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%A2%D0%BE%D0%BD%D0%BD%D0%B5%D0%BB%D1%8C" title="Тоннель – Russian" lang="ru" hreflang="ru" data-title="Тоннель" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sq mw-list-item"><a href="https://sq.wikipedia.org/wiki/Tuneli" title="Tuneli – Albanian" lang="sq" hreflang="sq" data-title="Tuneli" data-language-autonym="Shqip" data-language-local-name="Albanian" class="interlanguage-link-target"><span>Shqip</span></a></li><li class="interlanguage-link interwiki-scn mw-list-item"><a href="https://scn.wikipedia.org/wiki/Jallir%C3%ACa_(t%C3%B9nnilli)" title="Jallirìa (tùnnilli) – Sicilian" lang="scn" hreflang="scn" data-title="Jallirìa (tùnnilli)" data-language-autonym="Sicilianu" data-language-local-name="Sicilian" class="interlanguage-link-target"><span>Sicilianu</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Tunnel" title="Tunnel – Simple English" lang="en-simple" hreflang="en-simple" data-title="Tunnel" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Tunel" title="Tunel – Slovak" lang="sk" hreflang="sk" data-title="Tunel" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Predor" title="Predor – Slovenian" lang="sl" hreflang="sl" data-title="Predor" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%D8%AA%D9%88%D9%86%DB%8E%D9%84" title="تونێل – Central Kurdish" lang="ckb" hreflang="ckb" data-title="تونێل" data-language-autonym="کوردی" data-language-local-name="Central Kurdish" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D0%B5%D0%BB" title="Тунел – Serbian" lang="sr" hreflang="sr" data-title="Тунел" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Tunel" title="Tunel – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Tunel" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Tunneli" title="Tunneli – Finnish" lang="fi" hreflang="fi" data-title="Tunneli" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Tunnel" title="Tunnel – Swedish" lang="sv" hreflang="sv" data-title="Tunnel" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%9A%E0%AF%81%E0%AE%B0%E0%AE%99%E0%AF%8D%E0%AE%95%E0%AE%AA%E0%AF%8D%E0%AE%AA%E0%AE%BE%E0%AE%A4%E0%AF%88" title="சுரங்கப்பாதை – Tamil" lang="ta" hreflang="ta" data-title="சுரங்கப்பாதை" data-language-autonym="தமிழ்" data-language-local-name="Tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-te mw-list-item"><a href="https://te.wikipedia.org/wiki/%E0%B0%B8%E0%B1%8A%E0%B0%B0%E0%B0%82%E0%B0%97%E0%B0%82" title="సొరంగం – Telugu" lang="te" hreflang="te" data-title="సొరంగం" data-language-autonym="తెలుగు" data-language-local-name="Telugu" class="interlanguage-link-target"><span>తెలుగు</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%AD%E0%B8%B8%E0%B9%82%E0%B8%A1%E0%B8%87%E0%B8%84%E0%B9%8C" title="อุโมงค์ – Thai" lang="th" hreflang="th" data-title="อุโมงค์" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tg mw-list-item"><a href="https://tg.wikipedia.org/wiki/%D0%A2%D1%83%D0%BD%D0%BD%D0%B5%D0%BB" title="Туннел – Tajik" lang="tg" hreflang="tg" data-title="Туннел" data-language-autonym="Тоҷикӣ" data-language-local-name="Tajik" class="interlanguage-link-target"><span>Тоҷикӣ</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/T%C3%BCnel" title="Tünel – Turkish" lang="tr" hreflang="tr" data-title="Tünel" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a 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free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Underground passage made for traffic</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">This article is about underground passages. For other uses, see <a href="/wiki/Tunnel_(disambiguation)" class="mw-disambig" title="Tunnel (disambiguation)">Tunnel (disambiguation)</a>.</div> <p class="mw-empty-elt"> </p> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg/220px-Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg/330px-Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c1/Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg/440px-Signalisation_routi%C3%A8re_entr%C3%A9e_sud_tunnel_du_Galibier.jpg 2x" data-file-width="4000" data-file-height="3000" /></a><figcaption>Tunnel in <a href="/wiki/Col_du_Galibier" title="Col du Galibier">Col du Galibier</a>, France</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:14-46-35-f-mutzig.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/14-46-35-f-mutzig.jpg/220px-14-46-35-f-mutzig.jpg" decoding="async" width="220" height="146" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/14-46-35-f-mutzig.jpg/330px-14-46-35-f-mutzig.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/42/14-46-35-f-mutzig.jpg/440px-14-46-35-f-mutzig.jpg 2x" data-file-width="4288" data-file-height="2847" /></a><figcaption>Tunnel in <a href="/wiki/Fort_de_Mutzig" title="Fort de Mutzig">Fort de Mutzig</a>, France</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Tunel_en_Guanajuato.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/64/Tunel_en_Guanajuato.jpg/220px-Tunel_en_Guanajuato.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/64/Tunel_en_Guanajuato.jpg/330px-Tunel_en_Guanajuato.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/64/Tunel_en_Guanajuato.jpg/440px-Tunel_en_Guanajuato.jpg 2x" data-file-width="1563" data-file-height="1043" /></a><figcaption>Decorated portal to a road tunnel in <a href="/wiki/Guanajuato" title="Guanajuato">Guanajuato</a>, Mexico</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Heatpipe_tunnel_copenhagen_2009.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Heatpipe_tunnel_copenhagen_2009.jpg/220px-Heatpipe_tunnel_copenhagen_2009.jpg" decoding="async" width="220" height="146" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Heatpipe_tunnel_copenhagen_2009.jpg/330px-Heatpipe_tunnel_copenhagen_2009.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Heatpipe_tunnel_copenhagen_2009.jpg/440px-Heatpipe_tunnel_copenhagen_2009.jpg 2x" data-file-width="4256" data-file-height="2832" /></a><figcaption><a href="/wiki/Utility_tunnel" title="Utility tunnel">Utility tunnel</a> for heating pipes between <a href="/wiki/Rigshospitalet" title="Rigshospitalet">Rigshospitalet</a> and Amagerværket in <a href="/wiki/Copenhagen" title="Copenhagen">Copenhagen</a>, Denmark</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fb/A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG/220px-A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fb/A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG/330px-A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fb/A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG/440px-A_crossover_on_the_south_side_of_Zhongxiao_Xinsheng_Station.JPG 2x" data-file-width="3456" data-file-height="2592" /></a><figcaption>Tunnel on the <a href="/wiki/Taipei_Metro" title="Taipei Metro">Taipei Metro</a> in <a href="/wiki/Taiwan" title="Taiwan">Taiwan</a></figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg/220px-Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg/330px-Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg/440px-Southern_portal_of_Chirk_canal_tunnel_-_geograph.org.uk_-_1293092.jpg 2x" data-file-width="640" data-file-height="480" /></a><figcaption>Southern portal of the 421 m long (1,381 ft) <a href="/wiki/Chirk_Tunnel" title="Chirk Tunnel">Chirk canal tunnel</a>, Wales</figcaption></figure> <p>A <b>tunnel</b> is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two <a href="/wiki/Portal_(architecture)" title="Portal (architecture)">portals</a> common at each end, though there may be access and ventilation openings at various points along the length. A <a href="/wiki/Pipeline_transport" class="mw-redirect" title="Pipeline transport">pipeline</a> differs significantly from a tunnel,<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> though some recent tunnels have used <a href="/wiki/Immersed_tube" title="Immersed tube">immersed tube</a> construction techniques rather than traditional tunnel boring methods.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>A tunnel may be for foot or vehicular <a href="/wiki/Road" title="Road">road</a> <a href="/wiki/Traffic" title="Traffic">traffic</a>, for <a href="/wiki/Rail_transport" title="Rail transport">rail</a> traffic, or for a <a href="/wiki/Canal" title="Canal">canal</a>. The central portions of a <a href="/wiki/Rapid_transit" title="Rapid transit">rapid transit</a> network are usually in the tunnel. Some tunnels are used as <a href="/wiki/Sanitary_sewer" title="Sanitary sewer">sewers</a> or <a href="/wiki/Aqueduct_(watercourse)" class="mw-redirect" title="Aqueduct (watercourse)">aqueducts</a> to supply water for consumption or for <a href="/wiki/Hydroelectric" class="mw-redirect" title="Hydroelectric">hydroelectric</a> stations. <a href="/wiki/Utility_tunnel" title="Utility tunnel">Utility tunnels</a> are used for routing steam, chilled water, electrical power or telecommunication cables, as well as connecting buildings for convenient passage of people and equipment.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Secret_passage" title="Secret passage">Secret tunnels</a> are built for military purposes, or by civilians for <a href="/wiki/Smuggling" title="Smuggling">smuggling</a> of <a href="/wiki/Weapon" title="Weapon">weapons</a>, <a href="/wiki/Contraband" title="Contraband">contraband</a>, or <a href="/wiki/People" title="People">people</a>.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Special tunnels, such as <a href="/wiki/Wildlife_crossing" title="Wildlife crossing">wildlife crossings</a>, are built to allow wildlife to cross human-made barriers safely.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Tunnels can be connected together in <a href="/wiki/Tunnel_network" title="Tunnel network">tunnel networks</a>. </p><p>A tunnel is relatively long and narrow; the length is often much greater than twice the <a href="/wiki/Diameter" title="Diameter">diameter</a>, although similar shorter excavations can be constructed, such as cross passages between tunnels. The definition of what constitutes a tunnel can vary widely from source to source. For example, in the United Kingdom, a road tunnel is defined as "a subsurface highway structure enclosed for a length of 150 metres (490 ft) or more."<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> In the United States, the <a href="/wiki/National_Fire_Protection_Association" title="National Fire Protection Association">NFPA</a> definition of a tunnel is "An underground structure with a design length greater than 23 m (75 ft) and a diameter greater than 1,800 millimetres (5.9 ft)."<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Etymology">Etymology</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=1" title="Edit section: Etymology"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The word "tunnel" comes from the <a href="/wiki/Middle_English" title="Middle English">Middle English</a> <i>tonnelle</i>, meaning "a net", derived from <a href="/wiki/Old_French" title="Old French">Old French</a> <i>tonnel</i>, a diminutive of <i>tonne</i> ("cask"). The modern meaning, referring to an underground passageway, evolved in the 16th century as a metaphor for a narrow, confined space like the inside of a cask.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="History">History</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=2" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/History_of_water_supply_and_sanitation" title="History of water supply and sanitation">History of water supply and sanitation</a></div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-Expand_section plainlinks metadata ambox mbox-small-left ambox-content" role="presentation"><tbody><tr><td class="mbox-image"><span typeof="mw:File"><a href="/wiki/File:Wiki_letter_w_cropped.svg" class="mw-file-description"><img alt="[icon]" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Wiki_letter_w_cropped.svg/20px-Wiki_letter_w_cropped.svg.png" decoding="async" width="20" height="14" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Wiki_letter_w_cropped.svg/30px-Wiki_letter_w_cropped.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1c/Wiki_letter_w_cropped.svg/40px-Wiki_letter_w_cropped.svg.png 2x" data-file-width="44" data-file-height="31" /></a></span></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs expansion</b>. You can help by <a class="external text" href="https://en.wikipedia.org/w/index.php?title=Tunnel&action=edit&section=">adding to it</a>. <span class="date-container"><i>(<span class="date">March 2013</span>)</i></span></div></td></tr></tbody></table><p> Some of the earliest tunnels used by humans were <a href="/wiki/Paleoburrow" title="Paleoburrow">paleoburrows</a> excavated by prehistoric mammals.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup></p><figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Joralemon_Street_Tunnel_postcard,_1913.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Joralemon_Street_Tunnel_postcard%2C_1913.jpg/220px-Joralemon_Street_Tunnel_postcard%2C_1913.jpg" decoding="async" width="220" height="148" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Joralemon_Street_Tunnel_postcard%2C_1913.jpg/330px-Joralemon_Street_Tunnel_postcard%2C_1913.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Joralemon_Street_Tunnel_postcard%2C_1913.jpg/440px-Joralemon_Street_Tunnel_postcard%2C_1913.jpg 2x" data-file-width="1280" data-file-height="859" /></a><figcaption>Joralemon Street Tunnel on 1913 postcard, part of the <a href="/wiki/New_York_City_Subway" title="New York City Subway">New York City Subway</a> system</figcaption></figure> <p>Much of the early technology of tunneling evolved from <a href="/wiki/Mining" title="Mining">mining</a> and <a href="/wiki/Military_engineering" title="Military engineering">military engineering</a>. The etymology of the terms "mining" (for mineral extraction or for <a href="/wiki/Mining_(military)" class="mw-redirect" title="Mining (military)">siege attacks</a>), "<a href="/wiki/Military_engineering" title="Military engineering">military engineering</a>", and "<a href="/wiki/Civil_engineering" title="Civil engineering">civil engineering</a>" reveals these deep historic connections. </p> <div class="mw-heading mw-heading3"><h3 id="Antiquity_and_early_middle_ages">Antiquity and early middle ages</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=3" title="Edit section: Antiquity and early middle ages"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Predecessors of modern tunnels were <a href="/wiki/Adit" title="Adit">adits</a> that transported water for <a href="/wiki/Irrigation" title="Irrigation">irrigation</a>, drinking, or <a href="/wiki/Sewerage" title="Sewerage">sewerage</a>. The first <a href="/wiki/Qanat" title="Qanat">qanats</a> are known from before 2000 BC. </p><p>The earliest tunnel known to have been excavated from both ends is the <a href="/wiki/Siloam_tunnel" title="Siloam tunnel">Siloam Tunnel</a>, built in <a href="/wiki/Jerusalem" title="Jerusalem">Jerusalem</a> by the kings of <a href="/wiki/Kingdom_of_Judah" title="Kingdom of Judah">Judah</a> around the 8th century BC.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> Another tunnel excavated from both ends, maybe the second known, is the <a href="/wiki/Tunnel_of_Eupalinos" title="Tunnel of Eupalinos">Tunnel of Eupalinos</a>, which is a tunnel <a href="/wiki/Aqueduct_(water_supply)" title="Aqueduct (water supply)">aqueduct</a> 1,036 m (3,400 ft) long running through Mount Kastro in <a href="/wiki/Samos_Island" class="mw-redirect" title="Samos Island">Samos</a>, Greece. It was built in the 6th century BC to serve as an <a href="/wiki/Aqueduct_(water_supply)" title="Aqueduct (water supply)">aqueduct</a>. </p><p>In <a href="/wiki/Ethiopia" title="Ethiopia">Ethiopia</a>, the <a href="/wiki/Siqurto_foot_tunnel" title="Siqurto foot tunnel">Siqurto foot tunnel</a>, hand-hewn in the Middle Ages, crosses a mountain ridge. </p><p>In the <a href="/wiki/Gaza_Strip" title="Gaza Strip">Gaza Strip</a>, the network of tunnels was used by Jewish strategists as rock-cut shelters, in first links to Judean resistance against Roman rule in the <a href="/wiki/Bar_Kokhba_revolt" title="Bar Kokhba revolt">Bar Kokhba revolt</a> during the 2nd century AD. </p> <div class="mw-heading mw-heading2"><h2 id="Geotechnical_investigation_and_design">Geotechnical investigation and design</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=4" title="Edit section: Geotechnical investigation and design"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Geotechnical_investigation" title="Geotechnical investigation">Geotechnical investigation</a></div> <p>A major tunnel project must start with a comprehensive investigation of ground conditions by collecting samples from <a href="/wiki/Borehole" title="Borehole">boreholes</a> and by other geophysical techniques.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> An informed choice can then be made of machinery and methods for excavation and ground support, which will reduce the risk of encountering unforeseen ground conditions. In planning the route, the horizontal and vertical alignments can be selected to make use of the best ground and water conditions. It is common practice to locate a tunnel deeper than otherwise would be required, in order to excavate through solid rock or other material that is easier to support during construction. </p><p>Conventional desk and preliminary site studies may yield insufficient information to assess such factors as the blocky nature of rocks, the exact location of fault zones, or the stand-up times of softer ground. This may be a particular concern in large-diameter tunnels. To give more information, a pilot tunnel (or "drift tunnel") may be driven ahead of the main excavation. This smaller tunnel is less likely to collapse catastrophically should unexpected conditions be met, and it can be incorporated into the final tunnel or used as a backup or emergency escape passage. Alternatively, horizontal boreholes may sometimes be drilled ahead of the advancing tunnel face. </p><p>Other key geotechnical factors: </p> <ul><li><b>Stand-up time</b> is the amount of time a newly excavated cavity can support itself without any added structures. Knowing this parameter allows the engineers to determine how far an excavation can proceed before support is needed, which in turn affects the speed, efficiency, and cost of construction. Generally, certain configurations of rock and clay will have the greatest stand-up time, while sand and fine soils will have a much lower stand-up time.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Groundwater" title="Groundwater">Groundwater</a> control is very important in tunnel construction. Water leaking into a tunnel or vertical shaft will greatly decrease stand-up time, causing the excavation to become unstable and risking collapse. The most common way to control groundwater is to install dewatering pipes into the ground and to simply pump the water out.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> A very effective but expensive technology is <a href="/wiki/Ground_freezing" title="Ground freezing">ground freezing</a>, using pipes which are inserted into the ground surrounding the excavation, which are then cooled with special refrigerant fluids. This freezes the ground around each pipe until the whole space is surrounded with frozen soil, keeping water out until a permanent structure can be built.</li> <li>Tunnel <a href="/wiki/Cross_section_(geometry)" title="Cross section (geometry)">cross-sectional shape</a> is also very important in determining stand-up time. If a tunnel excavation is wider than it is high, it will have a harder time supporting itself, decreasing its stand-up time. A square or rectangular excavation is more difficult to make self-supporting, because of a concentration of <a href="/wiki/Stress_(mechanics)" title="Stress (mechanics)">stress</a> at the corners.<sup id="cite_ref-Engineers._1978_14-0" class="reference"><a href="#cite_note-Engineers._1978-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading3"><h3 id="Choice_of_tunnels_versus_bridges">Choice of tunnels versus bridges</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=5" title="Edit section: Choice of tunnels versus bridges"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444"><table class="box-Unreferenced_section plainlinks metadata ambox ambox-content ambox-Unreferenced" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>does not <a href="/wiki/Wikipedia:Citing_sources" title="Wikipedia:Citing sources">cite</a> any <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">sources</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Tunnel" title="Special:EditPage/Tunnel">improve this section</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and <a href="/wiki/Wikipedia:Verifiability#Burden_of_evidence" title="Wikipedia:Verifiability">removed</a>.</span> <span class="date-container"><i>(<span class="date">February 2021</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <p><span class="anchor" id="Choice_of_tunnels_vs_bridges"></span> </p> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:2007_09_19_-_895tunnel_-_WB_3.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/2007_09_19_-_895tunnel_-_WB_3.JPG/220px-2007_09_19_-_895tunnel_-_WB_3.JPG" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/2007_09_19_-_895tunnel_-_WB_3.JPG/330px-2007_09_19_-_895tunnel_-_WB_3.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/37/2007_09_19_-_895tunnel_-_WB_3.JPG/440px-2007_09_19_-_895tunnel_-_WB_3.JPG 2x" data-file-width="3648" data-file-height="2736" /></a><figcaption>The <a href="/wiki/Harbor_Tunnel_(Baltimore)" class="mw-redirect" title="Harbor Tunnel (Baltimore)">Harbor Tunnel</a> in <a href="/wiki/Baltimore" title="Baltimore">Baltimore</a>, USA, which carries <a href="/wiki/Interstate_895_(Maryland)" class="mw-redirect" title="Interstate 895 (Maryland)">I-895</a>, serves as an example of a water-crossing tunnel built instead of a bridge.</figcaption></figure> <p>For water crossings, a tunnel is generally more costly to construct than a bridge.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> However, both navigational and traffic considerations may limit the use of high bridges or <a href="/wiki/Drawbridge" title="Drawbridge">drawbridges</a> intersecting with shipping channels, necessitating a tunnel. </p><p>Bridges usually require a larger footprint on each shore than tunnels. In areas with expensive real estate, such as <a href="/wiki/Manhattan" title="Manhattan">Manhattan</a> and urban <a href="/wiki/Hong_Kong" title="Hong Kong">Hong Kong</a>, this is a strong factor in favor of a tunnel. Boston's <a href="/wiki/Big_Dig" title="Big Dig">Big Dig</a> project replaced elevated roadways with a tunnel system to increase traffic capacity, hide traffic, reclaim land, redecorate, and reunite the city with the waterfront.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p><p>The 1934 <a href="/wiki/Queensway_Tunnel" title="Queensway Tunnel">Queensway Tunnel</a> under the <a href="/wiki/River_Mersey" title="River Mersey">River Mersey</a> at <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a> was chosen over a massively high bridge partly for defense reasons; it was feared that aircraft could destroy a bridge in times of war, not merely impairing road traffic but blocking the river to navigation.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> Maintenance costs of a massive bridge to allow the world's largest ships to navigate under were considered higher than for a tunnel. Similar conclusions were reached for the 1971 <a href="/wiki/Kingsway_Tunnel" title="Kingsway Tunnel">Kingsway Tunnel</a> under the Mersey. In <a href="/wiki/Hampton_Roads,_Virginia" class="mw-redirect" title="Hampton Roads, Virginia">Hampton Roads, Virginia</a>, tunnels were chosen over bridges for strategic considerations; in the event of damage, bridges might prevent <a href="/wiki/US_Navy" class="mw-redirect" title="US Navy">US Navy</a> vessels from leaving <a href="/wiki/Naval_Station_Norfolk" title="Naval Station Norfolk">Naval Station Norfolk</a>. </p><p>Water-crossing tunnels built instead of bridges include the <a href="/wiki/Seikan_Tunnel" title="Seikan Tunnel">Seikan Tunnel</a> in Japan; the <a href="/wiki/Holland_Tunnel" title="Holland Tunnel">Holland Tunnel</a> and <a href="/wiki/Lincoln_Tunnel" title="Lincoln Tunnel">Lincoln Tunnel</a> between <a href="/wiki/New_Jersey" title="New Jersey">New Jersey</a> and Manhattan in <a href="/wiki/New_York_City" title="New York City">New York City</a>; the <a href="/wiki/Queens-Midtown_Tunnel" class="mw-redirect" title="Queens-Midtown Tunnel">Queens-Midtown Tunnel</a> between Manhattan and the <a href="/wiki/Borough_(New_York_City)" class="mw-redirect" title="Borough (New York City)">borough</a> of <a href="/wiki/Queens" title="Queens">Queens</a> on <a href="/wiki/Long_Island" title="Long Island">Long Island</a>; the <a href="/wiki/Detroit-Windsor_Tunnel" class="mw-redirect" title="Detroit-Windsor Tunnel">Detroit-Windsor Tunnel</a> between <a href="/wiki/Michigan" title="Michigan">Michigan</a> and <a href="/wiki/Ontario,_Canada" class="mw-redirect" title="Ontario, Canada">Ontario</a>; and the <a href="/wiki/Elizabeth_River_(Virginia)" title="Elizabeth River (Virginia)">Elizabeth River</a> tunnels between <a href="/wiki/Norfolk,_Virginia" title="Norfolk, Virginia">Norfolk</a> and <a href="/wiki/Portsmouth,_Virginia" title="Portsmouth, Virginia">Portsmouth, Virginia</a>; the 1934 <a href="/wiki/River_Mersey" title="River Mersey">River Mersey</a> road <a href="/wiki/Queensway_Tunnel" title="Queensway Tunnel">Queensway Tunnel</a>; the <a href="/wiki/Western_Scheldt_Tunnel" title="Western Scheldt Tunnel">Western Scheldt Tunnel</a>, Zeeland, Netherlands; and the <a href="/wiki/North_Shore_Connector" title="North Shore Connector">North Shore Connector</a> tunnel in <a href="/wiki/Pittsburgh,_Pennsylvania" class="mw-redirect" title="Pittsburgh, Pennsylvania">Pittsburgh, Pennsylvania</a>. The <a href="/wiki/Sydney_Harbour_Tunnel" title="Sydney Harbour Tunnel">Sydney Harbour Tunnel</a> was constructed to provide a second harbour crossing and to alleviate traffic congestion on the <a href="/wiki/Sydney_Harbour_Bridge" title="Sydney Harbour Bridge">Sydney Harbour Bridge</a>, without spoiling the iconic view. </p><p>Other reasons for choosing a tunnel instead of a bridge include avoiding difficulties with tides, weather, and shipping during construction (as in the 51.5-kilometre or 32.0-mile <a href="/wiki/Channel_Tunnel" title="Channel Tunnel">Channel Tunnel</a>), aesthetic reasons (preserving the above-ground view, landscape, and scenery), and also for weight capacity reasons (it may be more feasible to build a tunnel than a sufficiently strong bridge). </p><p>Some water crossings are a mixture of bridges and tunnels, such as the <a href="/wiki/Oresund_Bridge" class="mw-redirect" title="Oresund Bridge">Denmark to Sweden link</a> and the <a href="/wiki/Chesapeake_Bay_Bridge-Tunnel" class="mw-redirect" title="Chesapeake Bay Bridge-Tunnel">Chesapeake Bay Bridge-Tunnel</a> in <a href="/wiki/Virginia" title="Virginia">Virginia</a>. </p><p>There are particular hazards with tunnels, especially from vehicle fires when combustion gases can <a href="/wiki/Asphyxia" title="Asphyxia">asphyxiate</a> users, as happened at the <a href="/wiki/Gotthard_Road_Tunnel#2001_collision_and_fire" title="Gotthard Road Tunnel">Gotthard Road Tunnel</a> in <a href="/wiki/Switzerland" title="Switzerland">Switzerland</a> in 2001. One of the worst railway disasters ever, the <a href="/wiki/Balvano_train_disaster" title="Balvano train disaster">Balvano train disaster</a>, was caused by a train stalling in the Armi tunnel in <a href="/wiki/Italy" title="Italy">Italy</a> in 1944, killing 426 passengers. Designers try to reduce these risks by installing emergency ventilation systems or isolated emergency escape tunnels parallel to the main passage. </p> <div class="mw-heading mw-heading3"><h3 id="Project_planning_and_cost_estimates">Project planning and cost estimates</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=6" title="Edit section: Project planning and cost estimates"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Government funds are often required for the creation of tunnels.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> When a tunnel is being planned or constructed, economics and politics play a large factor in the decision making process. Civil engineers usually use <a href="/wiki/Project_management" title="Project management">project management</a> techniques for developing a major structure. Understanding the amount of time the project requires, and the amount of labor and materials needed is a crucial part of project planning. The project duration must be identified using a <a href="/wiki/Work_breakdown_structure" title="Work breakdown structure">work breakdown structure</a> and <a href="/wiki/Critical_path_method" title="Critical path method">critical path method</a>. Also, the land needed for excavation and construction staging, and the proper machinery must be selected. Large infrastructure projects require millions or even billions of dollars, involving long-term financing, usually through issuance of <a href="/wiki/Bond_(finance)" title="Bond (finance)">bonds</a>. </p><p>The <a href="/wiki/Cost%E2%80%93benefit_analysis" title="Cost–benefit analysis">costs and benefits</a> for an infrastructure such as a tunnel must be identified. Political disputes can occur, as in 2005 when the US House of Representatives approved a $100 million federal grant to build a tunnel under New York Harbor. However, the <a href="/wiki/Port_Authority_of_New_York_and_New_Jersey" title="Port Authority of New York and New Jersey">Port Authority of New York and New Jersey</a> was not aware of this bill and had not asked for a grant for such a project.<sup id="cite_ref-19" class="reference"><a href="#cite_note-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> Increased taxes to finance a large project may cause opposition.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Construction">Construction</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=7" title="Edit section: Construction"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Tunnel_construction" title="Tunnel construction">Tunnel construction</a></div> <p><span class="anchor" id="Construction"></span> <span class="anchor" id="Cut-and-cover"></span> Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the groundwater conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and the shape of the tunnel and appropriate risk management. </p><p>There are three basic types of tunnel construction in common use. Cut-and-cover tunnels are constructed in a shallow trench and then covered over. Bored tunnels are constructed in situ, without removing the ground above. Finally, a tube can be sunk into a body of water, which is called an immersed tunnel. </p> <div class="mw-heading mw-heading3"><h3 id="Cut-and-cover">Cut-and-cover</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=8" title="Edit section: Cut-and-cover"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Paris_Metro_construction_03300288-3.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Paris_Metro_construction_03300288-3.jpg/220px-Paris_Metro_construction_03300288-3.jpg" decoding="async" width="220" height="166" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Paris_Metro_construction_03300288-3.jpg/330px-Paris_Metro_construction_03300288-3.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f7/Paris_Metro_construction_03300288-3.jpg/440px-Paris_Metro_construction_03300288-3.jpg 2x" data-file-width="678" data-file-height="512" /></a><figcaption>Cut-and-cover construction at <a href="/wiki/Saint-Michel_(Paris_M%C3%A9tro)" class="mw-redirect" title="Saint-Michel (Paris Métro)">Saint-Michel</a> on <a href="/wiki/Paris_M%C3%A9tro" title="Paris Métro">Paris Métro</a> <a href="/wiki/Paris_M%C3%A9tro_Line_4" title="Paris Métro Line 4">Line 4</a> (c. 1910)</figcaption></figure> <p><b>Cut-and-cover</b> is a simple method of construction for shallow tunnels where a <a href="/wiki/Trench" title="Trench">trench</a> is excavated and <a href="/wiki/Roof" title="Roof">roofed</a> over with an overhead support system strong enough to carry the load of what is to be built above the tunnel.<sup id="cite_ref-FOOTNOTEEllis2015118_21-0" class="reference"><a href="#cite_note-FOOTNOTEEllis2015118-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> </p><p>There are two basic forms of cut-and-cover tunnelling: </p> <ul><li><i>Bottom-up method</i>: A trench is excavated, with ground support as necessary, and the tunnel is constructed in it. The tunnel may be of in situ concrete, precast concrete, precast arches, or corrugated steel arches; in early days brickwork was used. The trench is then carefully back-filled and the surface is reinstated.</li> <li><i>Top-down method</i>: Side support walls and capping beams are constructed from ground level by such methods as <a href="/wiki/Slurry_wall" title="Slurry wall">slurry walling</a> or contiguous bored piling. Only a shallow excavation is needed to construct the tunnel roof using precast beams or in situ concrete sitting on the walls. The surface is then reinstated except for access openings. This allows early reinstatement of roadways, services, and other surface features. Excavation then takes place under the permanent tunnel roof, and the base slab is constructed.</li></ul> <p>Shallow tunnels are often of the cut-and-cover type (if under water, of the immersed-tube type), while deep tunnels are excavated, often using a <a href="/wiki/Tunnelling_shield" title="Tunnelling shield">tunnelling shield</a>. For intermediate levels, both methods are possible. </p><p>Large cut-and-cover boxes are often used for underground <a href="/wiki/Rapid_transit" title="Rapid transit">metro</a> stations, such as <a href="/wiki/Canary_Wharf_tube_station" title="Canary Wharf tube station">Canary Wharf tube station</a> in London. This construction form generally has two levels, which allows economical arrangements for ticket hall, station platforms, passenger access and emergency egress, ventilation and smoke control, staff rooms, and equipment rooms. The interior of Canary Wharf station has been likened to an underground cathedral, owing to the sheer size of the excavation. This contrasts with many traditional stations on <a href="/wiki/London_Underground" title="London Underground">London Underground</a>, where bored tunnels were used for stations and passenger access. Nevertheless, the original parts of the London Underground network, the Metropolitan and District Railways, were constructed using cut-and-cover. These lines pre-dated electric traction and the proximity to the surface was useful to ventilate the inevitable smoke and steam. </p><p>A major disadvantage of cut-and-cover is the widespread disruption generated at the surface level during construction.<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup> This, and the availability of electric traction, brought about London Underground's switch to bored tunnels at a deeper level towards the end of the 19th century. </p><p>Prior to the replacement of manual excavation by the use of boring machines, <a href="/wiki/Victorian_era" title="Victorian era">Victorian</a> tunnel excavators developed a specialized method called clay-kicking for digging tunnels in clay-based soils. The clay-kicker lies on a plank at a 45-degree angle away from the working face and rather than a <a href="/wiki/Mattock" title="Mattock">mattock</a> with his hands, inserts with his feet a tool with a cup-like rounded end, then turns the tool with his hands to extract a section of soil, which is then placed on the waste extract. Clay-kicking is a specialized method developed in the <a href="/wiki/United_Kingdom" title="United Kingdom">United Kingdom</a> of digging tunnels in strong clay-based soil structures. This method of cut and cover construction required relatively little disturbance of property during the renewal of the United Kingdom's then ancient <a href="/wiki/Sewerage" title="Sewerage">sewerage</a> systems. It was also used during the <a href="/wiki/First_World_War" class="mw-redirect" title="First World War">First World War</a> by <a href="/wiki/Royal_Engineer_tunnelling_companies" class="mw-redirect" title="Royal Engineer tunnelling companies">Royal Engineer tunnelling companies</a> placing mines beneath <a href="/wiki/German_Empire" title="German Empire">German</a> lines, because it was almost silent and so not susceptible to listening methods of detection.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Boring_machines">Boring machines</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=9" title="Edit section: Boring machines"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Tunnel_boring_machine" title="Tunnel boring machine">Tunnel boring machine</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:TBM_S-210_Alptransit_Faido_East.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/70/TBM_S-210_Alptransit_Faido_East.jpg/220px-TBM_S-210_Alptransit_Faido_East.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/70/TBM_S-210_Alptransit_Faido_East.jpg/330px-TBM_S-210_Alptransit_Faido_East.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/70/TBM_S-210_Alptransit_Faido_East.jpg/440px-TBM_S-210_Alptransit_Faido_East.jpg 2x" data-file-width="1600" data-file-height="1200" /></a><figcaption>A workman is dwarfed by the cutting end of a <a href="/wiki/Tunnel_boring_machine" title="Tunnel boring machine">tunnel boring machine</a> used to excavate the <a href="/wiki/Gotthard_Base_Tunnel" title="Gotthard Base Tunnel">Gotthard Base Tunnel</a> (<a href="/wiki/Switzerland" title="Switzerland">Switzerland</a>), the world's longest railway tunnel.</figcaption></figure> <p><a href="/wiki/Tunnel_boring_machine" title="Tunnel boring machine">Tunnel boring machines</a> (TBMs) and associated back-up systems are used to highly automate the entire tunnelling process, reducing tunnelling costs. In certain predominantly urban applications, tunnel boring is viewed as a quick and cost-effective alternative to laying surface rails and roads. Expensive <a href="/wiki/Eminent_domain" title="Eminent domain">compulsory purchase</a> of buildings and land, with potentially lengthy planning inquiries, is eliminated. Disadvantages of TBMs arise from their usually large size – the difficulty of transporting the large TBM to the site of tunnel construction, or (alternatively) the high cost of assembling the TBM on-site, often within the confines of the tunnel being constructed. </p><p>There are a variety of TBM designs that can operate in a variety of conditions, from hard rock to soft water-bearing ground. Some TBMs, the bentonite slurry and earth-pressure balance types, have pressurized compartments at the front end, allowing them to be used in difficult conditions below the <a href="/wiki/Water_table" title="Water table">water table</a>. This pressurizes the ground ahead of the TBM cutter head to balance the water pressure. The operators work in normal air pressure behind the pressurized compartment, but may occasionally have to enter that compartment to renew or repair the cutters. This requires special precautions, such as local ground treatment or halting the TBM at a position free from water. Despite these difficulties, TBMs are now preferred over the older method of tunnelling in compressed air, with an airlock/decompression chamber some way back from the TBM, which required operators to <a href="/wiki/Work_in_compressed_air" title="Work in compressed air">work in high pressure</a> and go through decompression procedures at the end of their shifts, much like <a href="/wiki/Underwater_diving" title="Underwater diving">deep-sea divers</a>. </p><p>In February 2010, Aker Wirth delivered a TBM to Switzerland, for the expansion of the <a href="/wiki/Linth%E2%80%93Limmern_Power_Stations" title="Linth–Limmern Power Stations">Linth–Limmern Power Stations</a> located south of <a href="/wiki/Linthal,_Glarus" title="Linthal, Glarus">Linthal</a> in the <a href="/wiki/Canton_of_Glarus" title="Canton of Glarus">canton of Glarus</a>. The borehole has a diameter of 8.03 metres (26.3 ft).<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup> The four TBMs used for excavating the 57-kilometre (35 mi) <a href="/wiki/Gotthard_Base_Tunnel" title="Gotthard Base Tunnel">Gotthard Base Tunnel</a>, in <a href="/wiki/Switzerland" title="Switzerland">Switzerland</a>, had a diameter of about 9 metres (30 ft). A larger TBM was built to bore the Green Heart Tunnel (Dutch: Tunnel Groene Hart) as part of the <a href="/wiki/HSL-Zuid" title="HSL-Zuid">HSL-Zuid</a> in the Netherlands, with a diameter of 14.87 metres (48.8 ft).<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> This in turn was superseded by the <a href="/wiki/Autopista_de_Circunvalaci%C3%B3n_M-30" title="Autopista de Circunvalación M-30">Madrid M30 ringroad</a>, Spain, and the <a href="/wiki/Shanghai_Yangtze_River_Tunnel_and_Bridge" title="Shanghai Yangtze River Tunnel and Bridge">Chong Ming</a> tunnels in <a href="/wiki/Shanghai" title="Shanghai">Shanghai</a>, China. All of these machines were built at least partly by <a href="/wiki/Herrenknecht" title="Herrenknecht">Herrenknecht</a>. As of August 2013<sup class="plainlinks noexcerpt noprint asof-tag update" style="display:none;"><a class="external text" href="https://en.wikipedia.org/w/index.php?title=Tunnel&action=edit">[update]</a></sup>, the world's largest TBM was "<a href="/wiki/Bertha_(tunnel_boring_machine)" title="Bertha (tunnel boring machine)">Big Bertha</a>", a 17.5-metre (57.5 ft) diameter machine built by <a href="/wiki/Hitachi_Zosen_Corporation" title="Hitachi Zosen Corporation">Hitachi Zosen Corporation</a>, which dug the <a href="/wiki/Alaskan_Way_Viaduct_replacement_tunnel" class="mw-redirect" title="Alaskan Way Viaduct replacement tunnel">Alaskan Way Viaduct replacement tunnel</a> in <a href="/wiki/Seattle,_Washington" class="mw-redirect" title="Seattle, Washington">Seattle, Washington</a> (US).<sup id="cite_ref-NYT_Dec_2012_26-0" class="reference"><a href="#cite_note-NYT_Dec_2012-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Shafts">Shafts</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=10" title="Edit section: Shafts"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/23/Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png/220px-Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png" decoding="async" width="220" height="212" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/23/Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png/330px-Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/23/Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png/440px-Mersey_Railway_Tunnel_-_ventilation_and_drainage_machinery.png 2x" data-file-width="676" data-file-height="651" /></a><figcaption>1886 illustration showing the ventilation and drainage system of the Mersey railway tunnel</figcaption></figure> <p>A temporary access <a href="/wiki/Shaft_(civil_engineering)" title="Shaft (civil engineering)">shaft</a> is sometimes necessary during the excavation of a tunnel. They are usually circular and go straight down until they reach the level at which the tunnel is going to be built. A shaft normally has concrete walls and is usually built to be permanent. Once the access shafts are complete, TBMs are lowered to the bottom and excavation can start. Shafts are the main entrance in and out of the tunnel until the project is completed. If a tunnel is going to be long, multiple shafts at various locations may be bored so that entrance to the tunnel is closer to the unexcavated area.<sup id="cite_ref-Engineers._1978_14-1" class="reference"><a href="#cite_note-Engineers._1978-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> </p><p>Once construction is complete, construction access shafts are often used as <a href="/wiki/Ventilation_shaft" title="Ventilation shaft">ventilation shafts</a>, and may also be used as emergency exits. </p> <div class="mw-heading mw-heading3"><h3 id="Sprayed_concrete_techniques">Sprayed concrete techniques</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=11" title="Edit section: Sprayed concrete techniques"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The <a href="/wiki/New_Austrian_Tunnelling_method" class="mw-redirect" title="New Austrian Tunnelling method">New Austrian Tunnelling method</a> (NATM)—also referred to as the Sequential Excavation Method (SEM)<sup id="cite_ref-tbm20181205_27-0" class="reference"><a href="#cite_note-tbm20181205-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup>—was developed in the 1960s. The main idea of this method is to use the geological <a href="/wiki/Stress_(physics)" class="mw-redirect" title="Stress (physics)">stress</a> of the surrounding <a href="/wiki/Rock_(geology)" title="Rock (geology)">rock</a> <a href="/wiki/Mass" title="Mass">mass</a> to stabilize the tunnel, by allowing a measured relaxation and stress reassignment into the surrounding rock to prevent full loads becoming imposed on the supports. Based on <a href="/wiki/Geotechnical" class="mw-redirect" title="Geotechnical">geotechnical</a> measurements, an optimal <a href="/wiki/Cross_section_(geometry)" title="Cross section (geometry)">cross section</a> is computed. The excavation is protected by a layer of sprayed concrete, commonly referred to as <a href="/wiki/Shotcrete" title="Shotcrete">shotcrete</a>. Other support measures can include steel arches, rock bolts, and mesh. Technological developments in sprayed concrete technology have resulted in steel and polypropylene fibers being added to the concrete mix to improve lining strength. This creates a natural load-bearing ring, which minimizes the rock's <a href="/wiki/Deformation_(mechanics)" class="mw-redirect" title="Deformation (mechanics)">deformation</a>.<sup id="cite_ref-tbm20181205_27-1" class="reference"><a href="#cite_note-tbm20181205-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Hill_60_illowra_battery_port_kembla.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/Hill_60_illowra_battery_port_kembla.jpg/220px-Hill_60_illowra_battery_port_kembla.jpg" decoding="async" width="220" height="123" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/Hill_60_illowra_battery_port_kembla.jpg/330px-Hill_60_illowra_battery_port_kembla.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/66/Hill_60_illowra_battery_port_kembla.jpg/440px-Hill_60_illowra_battery_port_kembla.jpg 2x" data-file-width="2203" data-file-height="1228" /></a><figcaption><a href="/wiki/Illowra_Battery" title="Illowra Battery">Illowra Battery</a> utility tunnel, Port Kembla. One of many <a href="/wiki/Template:Barracks_Batteries_Bunkers_and_Forts_in_Sydney" title="Template:Barracks Batteries Bunkers and Forts in Sydney">bunkers south of Sydney</a>.</figcaption></figure> <p>By special <a href="/wiki/Condition_monitoring" title="Condition monitoring">monitoring</a> the NATM method is flexible, even at surprising changes of the <a href="/wiki/Geomechanics" title="Geomechanics">geomechanical</a> rock consistency during the tunneling work. The measured rock properties lead to appropriate <a href="/wiki/Tool" title="Tool">tools</a> for tunnel <a href="/wiki/Strength_of_materials" title="Strength of materials">strengthening</a>.<sup id="cite_ref-tbm20181205_27-2" class="reference"><a href="#cite_note-tbm20181205-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Pipe_jacking">Pipe jacking</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=12" title="Edit section: Pipe jacking"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Pipe_jacking" class="mw-redirect" title="Pipe jacking">Pipe jacking</a></div> <p>In <b><a href="/wiki/Pipe_jacking" class="mw-redirect" title="Pipe jacking">pipe jacking</a></b>, <a href="/wiki/Hydraulic_jack" class="mw-redirect" title="Hydraulic jack">hydraulic jacks</a> are used to push specially made pipes through the ground behind a TBM or shield. This method is commonly used to create tunnels under existing structures, such as roads or railways. Tunnels constructed by pipe jacking are normally small diameter bores with a maximum size of around 3.2 metres (10 ft). </p> <div class="mw-heading mw-heading3"><h3 id="Box_jacking">Box jacking</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=13" title="Edit section: Box jacking"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Box jacking is similar to pipe jacking, but instead of jacking tubes, a box-shaped tunnel is used. Jacked boxes can be a much larger span than a pipe jack, with the span of some box jacks in excess of 20 metres (66 ft). A cutting head is normally used at the front of the box being jacked, and spoil removal is normally by excavator from within the box. Recent developments of the Jacked Arch and Jacked deck have enabled longer and larger structures to be installed to close accuracy. </p> <div class="mw-heading mw-heading3"><h3 id="Underwater_tunnels">Underwater tunnels</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=14" title="Edit section: Underwater tunnels"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Georgiaaquariumtunnel.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Georgiaaquariumtunnel.jpg/220px-Georgiaaquariumtunnel.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Georgiaaquariumtunnel.jpg/330px-Georgiaaquariumtunnel.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/65/Georgiaaquariumtunnel.jpg/440px-Georgiaaquariumtunnel.jpg 2x" data-file-width="600" data-file-height="400" /></a><figcaption><a href="/wiki/Shark_tunnel" title="Shark tunnel">Shark tunnel</a> at the <a href="/wiki/Georgia_Aquarium" title="Georgia Aquarium">Georgia Aquarium</a></figcaption></figure> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Undersea_tunnel" class="mw-redirect" title="Undersea tunnel">Undersea tunnel</a></div> <p>There are also several approaches to underwater tunnels, the two most common being bored tunnels or <a href="/wiki/Immersed_tube" title="Immersed tube">immersed tubes</a>, examples are <a href="/wiki/Bj%C3%B8rvika_Tunnel" title="Bjørvika Tunnel">Bjørvika Tunnel</a> and <a href="/wiki/Marmaray" title="Marmaray">Marmaray</a>. <a href="/wiki/Submerged_floating_tunnel" title="Submerged floating tunnel">Submerged floating tunnels</a> are a novel approach under consideration; however, no such tunnels have been constructed to date. </p> <div class="mw-heading mw-heading3"><h3 id="Temporary_way">Temporary way</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=15" title="Edit section: Temporary way"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>During construction of a tunnel it is often convenient to install a temporary railway, particularly to remove <a href="/wiki/Spoil_tip" title="Spoil tip">excavated spoil</a>, often <a href="/wiki/Narrow_gauge" class="mw-redirect" title="Narrow gauge">narrow gauge</a> so that it can be <a href="/wiki/Double_track" class="mw-redirect" title="Double track">double track</a> to allow the operation of empty and loaded trains at the same time. The temporary way is replaced by the <a href="/wiki/Permanent_way" class="mw-redirect" title="Permanent way">permanent way</a> at completion, thus explaining the term "<a href="/wiki/Perway" class="mw-redirect" title="Perway">Perway</a>". </p> <div class="mw-heading mw-heading3"><h3 id="Enlargement">Enlargement</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=16" title="Edit section: Enlargement"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Kolektory_Praha,_15.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/79/Kolektory_Praha%2C_15.jpg/220px-Kolektory_Praha%2C_15.jpg" decoding="async" width="220" height="158" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/79/Kolektory_Praha%2C_15.jpg/330px-Kolektory_Praha%2C_15.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/79/Kolektory_Praha%2C_15.jpg/440px-Kolektory_Praha%2C_15.jpg 2x" data-file-width="3165" data-file-height="2280" /></a><figcaption>A utility tunnel in <a href="/wiki/Prague" title="Prague">Prague</a></figcaption></figure> <p>The vehicles or traffic using a tunnel can outgrow it, requiring replacement or enlargement: </p> <ul><li>The original single line <a href="/wiki/Mount_Gibraltar" title="Mount Gibraltar">Gib Tunnel</a> near <a href="/wiki/Mittagong" title="Mittagong">Mittagong</a> was replaced with a double-track tunnel, with the original tunnel used for growing mushrooms.<sup id="cite_ref-Company_Website_28-0" class="reference"><a href="#cite_note-Company_Website-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Article_on_Closure_29-0" class="reference"><a href="#cite_note-Article_on_Closure-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup></li> <li>The 1832 double-track 1.6-kilometre (1 mi)-long tunnel from <a href="/wiki/Edge_Hill_railway_station" title="Edge Hill railway station">Edge Hill</a> to <a href="/wiki/Liverpool_Lime_Street_railway_station" title="Liverpool Lime Street railway station">Lime Street</a> in <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a> was near totally removed, apart from a 50-metre (55 yd) section at Edge Hill and a section nearer to Lime Street, as four tracks were required. The tunnel was dug out into a very deep four-track cutting, with short tunnels in places along the cutting. Train services were not interrupted as the work progressed.<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> There are other occurrences of tunnels being replaced by open cuts, for example, the <a href="/wiki/Auburn_Tunnel" title="Auburn Tunnel">Auburn Tunnel</a>.</li> <li>The <a href="/wiki/Farnworth_Tunnel" class="mw-redirect" title="Farnworth Tunnel">Farnworth Tunnel</a> in England was enlarged using a <a href="/wiki/Tunnel_boring_machine" title="Tunnel boring machine">tunnel boring machine</a> (TBM) in 2015.<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> The <a href="/wiki/Rhyndaston_Tunnel" title="Rhyndaston Tunnel">Rhyndaston Tunnel</a> was enlarged using a borrowed TBM so as to be able to take <a href="/wiki/ISO_container" class="mw-redirect" title="ISO container">ISO containers</a>.</li> <li>Tunnels can also be enlarged by lowering the floor.<sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading3"><h3 id="Open_building_pit">Open building pit</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=17" title="Edit section: Open building pit"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>An open building pit consists of a horizontal and a vertical boundary that keeps groundwater and soil out of the pit. There are several potential alternatives and combinations for (horizontal and vertical) building pit boundaries. The most important difference with cut-and-cover is that the open building pit is muted after tunnel construction; no roof is placed. </p> <div class="mw-heading mw-heading3"><h3 id="Other_construction_methods">Other construction methods</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=18" title="Edit section: Other construction methods"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Tunnel_end_Onkalo.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Tunnel_end_Onkalo.jpg/220px-Tunnel_end_Onkalo.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Tunnel_end_Onkalo.jpg/330px-Tunnel_end_Onkalo.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Tunnel_end_Onkalo.jpg/440px-Tunnel_end_Onkalo.jpg 2x" data-file-width="5100" data-file-height="3400" /></a><figcaption>Tunnel excavated with drilling and blasting method.</figcaption></figure> <ul><li><a href="/wiki/Drilling_and_blasting" title="Drilling and blasting">Drilling and blasting</a></li> <li><a href="/wiki/Hydraulic_splitter" title="Hydraulic splitter">Hydraulic splitter</a></li> <li>Slurry-shield machine</li> <li>Wall-cover construction method.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Variant_tunnel_types">Variant tunnel types</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=19" title="Edit section: Variant tunnel types"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Double-deck_and_multipurpose_tunnels">Double-deck and multipurpose tunnels</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=20" title="Edit section: Double-deck and multipurpose tunnels"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:San_Francisco-Bay_Bridge02.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/San_Francisco-Bay_Bridge02.jpg/220px-San_Francisco-Bay_Bridge02.jpg" decoding="async" width="220" height="121" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/San_Francisco-Bay_Bridge02.jpg/330px-San_Francisco-Bay_Bridge02.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/42/San_Francisco-Bay_Bridge02.jpg/440px-San_Francisco-Bay_Bridge02.jpg 2x" data-file-width="1185" data-file-height="652" /></a><figcaption>The upper-level traffic lanes through <a href="/wiki/Yerba_Buena_Island" title="Yerba Buena Island">Yerba Buena Island</a>, part of the <a href="/wiki/San_Francisco%E2%80%93Oakland_Bay_Bridge" title="San Francisco–Oakland Bay Bridge">San Francisco–Oakland Bay Bridge</a></figcaption></figure> <p>Some tunnels are double-deck, for example, the two major segments of the <a href="/wiki/San_Francisco%E2%80%93Oakland_Bay_Bridge" title="San Francisco–Oakland Bay Bridge">San Francisco–Oakland Bay Bridge</a> (completed in 1936) are linked by a 160-metre (540 ft) <a href="/wiki/Yerba_Buena_Tunnel" title="Yerba Buena Tunnel">double-deck tunnel</a> section through <a href="/wiki/Yerba_Buena_Island" title="Yerba Buena Island">Yerba Buena Island</a>, the largest-diameter bored tunnel in the world.<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> At construction this was a combination bidirectional rail and truck pathway on the lower deck with automobiles above, now converted to one-way road vehicle traffic on each deck. </p><p>In Turkey, the <a href="/wiki/Eurasia_Tunnel" title="Eurasia Tunnel">Eurasia Tunnel</a> under the <a href="/wiki/Bosphorus" class="mw-redirect" title="Bosphorus">Bosphorus</a>, opened in 2016, has at its core a 5.4 km (3.4 miles) two-deck road tunnel with two lanes on each deck.<sup id="cite_ref-uc_35-0" class="reference"><a href="#cite_note-uc-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> </p><p>Additionally, in 2015 the Turkish government announced that it will build <i>three</i>-level tunnel, also under the Bosporus.<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup> The tunnel is intended to carry both the Istanbul metro and a two-level highway, over a length of 6.5 km (4.0 miles). </p><p>The French <a href="/wiki/A86_Duplex_Tunnel" class="mw-redirect" title="A86 Duplex Tunnel">A86 Duplex Tunnel</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://fr.wikipedia.org/wiki/Duplex_A86" class="extiw" title="fr:Duplex A86">fr</a>]</span> in west Paris consists of two bored tunnel tubes, the eastern one of which has two levels for light motorized vehicles, over a length of 10 km (6.2 miles). Although each level offers a physical height of 2.54 m (8.3 ft), only traffic up to 2 m (6.6 ft) tall is allowed in this tunnel tube, and motorcyclists are directed to the other tube. Each level was built with a three-lane roadway, but only two lanes per level are used – the third serves as a hard shoulder within the tunnel. The A86 Duplex is Europe's longest double-deck tunnel. </p><p>In <a href="/wiki/Shanghai" title="Shanghai">Shanghai</a>, China, a 2.8 km (1.7 miles) two-tube double-deck tunnel was built starting in 2002. In each tube of the <a href="/w/index.php?title=Fuxing_Road_Tunnel&action=edit&redlink=1" class="new" title="Fuxing Road Tunnel (page does not exist)">Fuxing Road Tunnel</a><span class="noprint" style="font-size:85%; font-style: normal;"> [<a href="https://zh.wikipedia.org/wiki/%E5%A4%8D%E5%85%B4%E4%B8%9C%E8%B7%AF%E9%9A%A7%E9%81%93" class="extiw" title="zh:复兴东路隧道">zh</a>]</span> both decks are for motor vehicles. In each direction, only cars and taxis travel on the 2.6 m (8.5 ft) high two-lane upper deck, and heavier vehicles, like trucks and buses, as well as cars, may use the 4.0 m (13 ft) high single-lane lower level.<sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup> </p><p>In the Netherlands, a 2.3 km (1.4 miles) two-storey, eight-lane, cut-and-cover road tunnel under the city of <a href="/wiki/Maastricht" title="Maastricht">Maastricht</a> was opened in 2016.<sup id="cite_ref-38" class="reference"><a href="#cite_note-38"><span class="cite-bracket">[</span>38<span class="cite-bracket">]</span></a></sup> Each level accommodates a full height, two by two-lane highway. The two lower tubes of the tunnel carry the <a href="/wiki/A2_motorway_(Netherlands)" title="A2 motorway (Netherlands)">A2 motorway</a>, which originates in Amsterdam, through the city; and the two upper tubes take the N2 regional highway for local traffic.<sup id="cite_ref-39" class="reference"><a href="#cite_note-39"><span class="cite-bracket">[</span>39<span class="cite-bracket">]</span></a></sup> </p><p>The <a href="/wiki/Alaskan_Way_Viaduct_replacement_tunnel" class="mw-redirect" title="Alaskan Way Viaduct replacement tunnel">Alaskan Way Viaduct replacement tunnel</a>, is a $3.3 billion 2.83-kilometre (1.76 mi), double-decker bored highway tunnel under <a href="/wiki/Downtown_Seattle" title="Downtown Seattle">Downtown Seattle</a>. Construction began in July 2013 using "<a href="/wiki/Bertha_(tunnel_boring_machine)" title="Bertha (tunnel boring machine)">Bertha</a>", at the time the world's largest <a href="/wiki/Earth_pressure_balance" class="mw-redirect" title="Earth pressure balance">earth pressure balance</a> tunnel boring machine, with a 17.5-metre (57.5 ft) cutterhead diameter. After several delays, tunnel boring was completed in April 2017, and the tunnel opened to traffic on 4 February 2019. </p><p><a href="/wiki/New_York_City" title="New York City">New York City</a>'s <a href="/wiki/63rd_Street_Tunnel" title="63rd Street Tunnel">63rd Street Tunnel</a> under the <a href="/wiki/East_River" title="East River">East River</a>, between the boroughs of <a href="/wiki/Manhattan" title="Manhattan">Manhattan</a> and <a href="/wiki/Queens" title="Queens">Queens</a>, was intended to carry <a href="/wiki/New_York_City_Subway" title="New York City Subway">subway</a> trains on the upper level and <a href="/wiki/Long_Island_Rail_Road" title="Long Island Rail Road">Long Island Rail Road</a> commuter trains on the lower level. Construction started in 1969,<sup id="cite_ref-40" class="reference"><a href="#cite_note-40"><span class="cite-bracket">[</span>40<span class="cite-bracket">]</span></a></sup> and the two sides of the tunnel were bored through in 1972.<sup id="cite_ref-41" class="reference"><a href="#cite_note-41"><span class="cite-bracket">[</span>41<span class="cite-bracket">]</span></a></sup> The upper level, used by the <a href="/wiki/63rd_Street_lines" title="63rd Street lines">IND 63rd Street Line</a> (<span class="nowrap"><a href="/wiki/F_(New_York_City_Subway_service)" title="F (New York City Subway service)">F</a></span> and <span class="nowrap"><a href="/wiki/Fd_(New_York_City_Subway_service)" class="mw-redirect" title="Fd (New York City Subway service)"><F></a></span> train) of the New York City Subway, was not opened for passenger service until 1989.<sup id="cite_ref-42" class="reference"><a href="#cite_note-42"><span class="cite-bracket">[</span>42<span class="cite-bracket">]</span></a></sup> The lower level, intended for commuter rail, saw passenger service after completion of the <a href="/wiki/East_Side_Access" title="East Side Access">East Side Access</a> project, in late 2022.<sup id="cite_ref-43" class="reference"><a href="#cite_note-43"><span class="cite-bracket">[</span>43<span class="cite-bracket">]</span></a></sup> </p><p>In the UK, the 1934 <a href="/wiki/Queensway_Tunnel" title="Queensway Tunnel">Queensway Tunnel</a> under the <a href="/wiki/River_Mersey" title="River Mersey">River Mersey</a> between <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a> and <a href="/wiki/Birkenhead" title="Birkenhead">Birkenhead</a> was originally to have road vehicles running on the upper deck and trams on the lower. During construction the tram usage was cancelled. The lower section is only used for cables, pipes and emergency accident refuge enclosures. </p><p>Hong Kong's <a href="/wiki/Lion_Rock_Tunnel" title="Lion Rock Tunnel">Lion Rock Tunnel</a>, built in the mid 1960s, connecting <a href="/wiki/New_Kowloon" title="New Kowloon">New Kowloon</a> and <a href="/wiki/Sha_Tin_New_Town" title="Sha Tin New Town">Sha Tin</a>, carries a motorway but also serves as an <a href="/wiki/Aqueduct_(water_supply)" title="Aqueduct (water supply)">aqueduct</a>, featuring a gallery containing five water mains lines with diameters between 1.2 and 1.5 m (4 and 5 ft) below the road section of the tunnel.<sup id="cite_ref-44" class="reference"><a href="#cite_note-44"><span class="cite-bracket">[</span>44<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Wuhan" title="Wuhan">Wuhan</a>'s Yangtze River Highway and Railway Tunnel is a 2.59 km (1.61 mi) two-tube double-deck tunnel under the <a href="/wiki/Yangtze" title="Yangtze">Yangtze River</a> completed in 2018. Each tube carries three lanes of local traffic on the top deck with one track <a href="/wiki/Wuhan_Metro" title="Wuhan Metro">Wuhan Metro</a> <a href="/wiki/Line_7_(Wuhan_Metro)" title="Line 7 (Wuhan Metro)">Line 7</a> on the lower deck.<sup id="cite_ref-45" class="reference"><a href="#cite_note-45"><span class="cite-bracket">[</span>45<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-46" class="reference"><a href="#cite_note-46"><span class="cite-bracket">[</span>46<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-47" class="reference"><a href="#cite_note-47"><span class="cite-bracket">[</span>47<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Mount_Baker_Tunnel" title="Mount Baker Tunnel">Mount Baker Tunnel</a> has three levels. The bottom level is to be used by <a href="/wiki/Sound_Transit" title="Sound Transit">Sound Transit</a> light rail. The middle level is used by car traffic, and the top layer is for bicycle and pedestrian access. </p><p>Some tunnels have more than one purpose. The <a href="/wiki/SMART_Tunnel" title="SMART Tunnel">SMART Tunnel</a> in <a href="/wiki/Malaysia" title="Malaysia">Malaysia</a> is the first multipurpose "<i>Stormwater Management And Road Tunnel</i>" in the world, created to convey both traffic and occasional <a href="/wiki/Flood" title="Flood">flood</a> waters in <a href="/wiki/Kuala_Lumpur" title="Kuala Lumpur">Kuala Lumpur</a>. When necessary, floodwater is first diverted into a separate bypass tunnel located <i>underneath</i> the 4.0 km (2.5 miles) double-deck roadway tunnel. In this scenario, traffic continues normally. Only during heavy, prolonged rains when the threat of extreme flooding is high, the upper tunnel tube is closed off to vehicles and automated flood control gates are opened so that water can be diverted through both tunnels.<sup id="cite_ref-48" class="reference"><a href="#cite_note-48"><span class="cite-bracket">[</span>48<span class="cite-bracket">]</span></a></sup> </p><p><a href="/wiki/Common_utility_duct" class="mw-redirect" title="Common utility duct">Common utility ducts</a> or utility tunnels carry two or more utility lines. Through co-location of different utilities in one tunnel, organizations are able to reduce the costs of building and maintaining utilities. </p> <div class="mw-heading mw-heading3"><h3 id="Covered_passageways">Covered passageways</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=21" title="Edit section: Covered passageways"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Sotetkapu.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Sotetkapu.JPG/170px-Sotetkapu.JPG" decoding="async" width="170" height="227" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Sotetkapu.JPG/255px-Sotetkapu.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Sotetkapu.JPG/340px-Sotetkapu.JPG 2x" data-file-width="1704" data-file-height="2272" /></a><figcaption>The 19th century <a href="/wiki/Dark_Gate" title="Dark Gate">Dark Gate</a> in <a href="/wiki/Esztergom" title="Esztergom">Esztergom</a>, Hungary</figcaption></figure> <p>Over-bridges can sometimes be built by covering a road or river or railway with <a href="/wiki/Brick" title="Brick">brick</a> or <a href="/wiki/Steel" title="Steel">steel</a> <a href="/wiki/Arch" title="Arch">arches</a>, and then leveling the surface with earth. In railway parlance, a surface-level track which has been built or covered over is normally called a "covered way". </p><p><a href="/wiki/Snow_shed" class="mw-redirect" title="Snow shed">Snow sheds</a> are a kind of artificial tunnel built to protect a railway from <a href="/wiki/Avalanche" title="Avalanche">avalanches</a> of snow. Similarly the <a href="/wiki/Stanwell_Park" class="mw-redirect" title="Stanwell Park">Stanwell Park</a>, <a href="/wiki/New_South_Wales" title="New South Wales">New South Wales</a> "steel tunnel", on the <a href="/wiki/Illawarra_railway_line" class="mw-redirect" title="Illawarra railway line">Illawarra railway line</a>, protects the line from rockfalls. </p> <div class="mw-heading mw-heading3"><h3 id="Underpass">Underpass</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=22" title="Edit section: Underpass"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">"Underpass" redirects here. For other uses, see <a href="/wiki/Underpass_(disambiguation)" class="mw-disambig" title="Underpass (disambiguation)">Underpass (disambiguation)</a>.</div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway,_Troutdale,_Multnomah_County,_OR_HAER_ORE,26-TROUT.V,1-31.tif" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/ec/VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway%2C_Troutdale%2C_Multnomah_County%2C_OR_HAER_ORE%2C26-TROUT.V%2C1-31.tif/lossy-page1-220px-VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway%2C_Troutdale%2C_Multnomah_County%2C_OR_HAER_ORE%2C26-TROUT.V%2C1-31.tif.jpg" decoding="async" width="220" height="156" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/ec/VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway%2C_Troutdale%2C_Multnomah_County%2C_OR_HAER_ORE%2C26-TROUT.V%2C1-31.tif/lossy-page1-330px-VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway%2C_Troutdale%2C_Multnomah_County%2C_OR_HAER_ORE%2C26-TROUT.V%2C1-31.tif.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/ec/VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway%2C_Troutdale%2C_Multnomah_County%2C_OR_HAER_ORE%2C26-TROUT.V%2C1-31.tif/lossy-page1-440px-VIEW_THROUGH_CATTLEPASS_NEAR_BRIDAL_VEIL_FALLS._-_Historic_Columbia_River_Highway%2C_Troutdale%2C_Multnomah_County%2C_OR_HAER_ORE%2C26-TROUT.V%2C1-31.tif.jpg 2x" data-file-width="5000" data-file-height="3538" /></a><figcaption>Underpass for cattle created in 1914 construction of what is now <a href="/wiki/Historic_Columbia_River_Highway" title="Historic Columbia River Highway">Historic Columbia River Highway</a></figcaption></figure> <p>An <b>underpass</b> is a road or railway or other passageway passing <i>under</i> another road or railway, under an <a href="/wiki/Overpass" title="Overpass">overpass</a>. This is not strictly a tunnel. </p> <div class="mw-heading mw-heading2"><h2 id="Safety_and_security">Safety and security</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=23" title="Edit section: Safety and security"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">"Tunnel fire" redirects here. For the 1991 wildfire in California, see <a href="/wiki/Oakland_firestorm_of_1991" title="Oakland firestorm of 1991">Oakland firestorm of 1991</a>. For the 2022 wildfire in Arizona, see <a href="/wiki/Tunnel_Fire_(2022)" title="Tunnel Fire (2022)">Tunnel Fire (2022)</a>.</div> <figure class="mw-default-size mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:Alma_tunnel_Paris.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Alma_tunnel_Paris.jpg/220px-Alma_tunnel_Paris.jpg" decoding="async" width="220" height="151" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Alma_tunnel_Paris.jpg/330px-Alma_tunnel_Paris.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Alma_tunnel_Paris.jpg/440px-Alma_tunnel_Paris.jpg 2x" data-file-width="1144" data-file-height="787" /></a><figcaption>The entrance to the <a href="/wiki/Pont_de_l%27Alma" title="Pont de l'Alma">Pont de l'Alma</a> tunnel, the site where the car carrying <a href="/wiki/Diana,_Princess_of_Wales" title="Diana, Princess of Wales">Diana, Princess of Wales</a>, <a href="/wiki/Death_of_Diana,_Princess_of_Wales" title="Death of Diana, Princess of Wales">hit a Fiat and then the wall</a>. There was no proper barrier and this contributed to her death.</figcaption></figure> <p>Owing to the enclosed space of a tunnel, fires can have very serious effects on users. The main dangers are gas and smoke production, with even low concentrations of <a href="/wiki/Carbon_monoxide" title="Carbon monoxide">carbon monoxide</a> being highly toxic. Fires killed 11 people in the <a href="/wiki/Gotthard_Road_Tunnel#History" title="Gotthard Road Tunnel">Gotthard tunnel fire</a> of 2001 for example, all of the victims succumbing to smoke and gas inhalation. Over 400 passengers died in the <a href="/wiki/Balvano_train_disaster" title="Balvano train disaster">Balvano train disaster</a> in Italy in 1944, when the locomotive halted in a long tunnel. <a href="/wiki/Carbon_monoxide_poisoning" title="Carbon monoxide poisoning">Carbon monoxide poisoning</a> was the main cause of death. In the <a href="/wiki/Caldecott_Tunnel_fire" title="Caldecott Tunnel fire">Caldecott Tunnel fire</a> of 1982, the majority of fatalities were caused by toxic smoke, rather than by the initial crash. Likewise 84 people were killed in the <a href="/wiki/Paris_M%C3%A9tro_train_fire" title="Paris Métro train fire">Paris Métro train fire</a> of 1904. </p><p>Motor vehicle tunnels usually require <a href="/wiki/Ventilation_shaft" title="Ventilation shaft">ventilation shafts</a> and powered fans to remove toxic <a href="/wiki/Exhaust_gas" title="Exhaust gas">exhaust gases</a> during routine operation.<sup id="cite_ref-Mishra_49-0" class="reference"><a href="#cite_note-Mishra-49"><span class="cite-bracket">[</span>49<span class="cite-bracket">]</span></a></sup> </p><p>Rail tunnels usually require fewer <a href="/wiki/Air_changes_per_hour" title="Air changes per hour">air changes per hour</a>, but still may require <a href="/wiki/Ventilation_(architecture)" title="Ventilation (architecture)">forced-air ventilation</a>. Both types of tunnels often have provisions to increase ventilation under emergency conditions, such as a fire. Although there is a risk of increasing the <a href="/wiki/Rate_of_combustion" class="mw-redirect" title="Rate of combustion">rate of combustion</a> through increased airflow, the primary focus is on providing breathable air to persons trapped in the tunnel, as well as <a href="/wiki/Firefighter" title="Firefighter">firefighters</a>. </p><p>The <a href="/wiki/Aerodynamics" title="Aerodynamics">aerodynamic</a> <a href="/wiki/Longitudinal_wave" title="Longitudinal wave">pressure wave</a> produced by <a href="/wiki/High-speed_rail" title="High-speed rail">high speed trains</a> entering a tunnel<sup id="cite_ref-50" class="reference"><a href="#cite_note-50"><span class="cite-bracket">[</span>50<span class="cite-bracket">]</span></a></sup> reflect at its open ends and change sign (<a href="/wiki/Compression_(physics)" title="Compression (physics)">compression</a> wavefront changes to <a href="/wiki/Rarefaction" title="Rarefaction">rarefaction</a> wavefront and vice versa). When two wavefronts of the same sign meet the train, significant and rapid air pressure<sup id="cite_ref-51" class="reference"><a href="#cite_note-51"><span class="cite-bracket">[</span>51<span class="cite-bracket">]</span></a></sup> may cause ear discomfort<sup id="cite_ref-52" class="reference"><a href="#cite_note-52"><span class="cite-bracket">[</span>52<span class="cite-bracket">]</span></a></sup> for passengers and crew. When a high-speed train exits a tunnel, a loud "<a href="/wiki/Piston_effect#Tunnel_boom" title="Piston effect">Tunnel boom</a>" may occur, which can disturb residents near the mouth of the tunnel, and it is exacerbated in mountain valleys where the sound can echo. </p><p>When there is a parallel, separate tunnel available, airtight but unlocked emergency doors are usually provided which allow trapped personnel to escape from a smoke-filled tunnel to the parallel tube.<sup id="cite_ref-53" class="reference"><a href="#cite_note-53"><span class="cite-bracket">[</span>53<span class="cite-bracket">]</span></a></sup> </p><p>Larger, heavily used tunnels, such as the <a href="/wiki/Big_Dig" title="Big Dig">Big Dig</a> tunnel in <a href="/wiki/Boston,_Massachusetts" class="mw-redirect" title="Boston, Massachusetts">Boston, Massachusetts</a>, may have a dedicated 24-hour staffed <a href="/wiki/Operations_center" class="mw-redirect" title="Operations center">operations center</a> which monitors and reports on traffic conditions, and responds to emergencies.<sup id="cite_ref-54" class="reference"><a href="#cite_note-54"><span class="cite-bracket">[</span>54<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Video_surveillance" class="mw-redirect" title="Video surveillance">Video surveillance</a> equipment is often used, and real-time pictures of traffic conditions for some highways may be viewable by the general public via the Internet. </p><p>A database of seismic damage to underground structures using 217 case histories shows the following general observations can be made regarding the seismic performance of underground structures: </p> <ul><li>Underground structures suffer appreciably less damage than surface structures.</li> <li>Reported damage decreases with increasing over burden depth. Deep tunnels seem to be safer and less vulnerable to earthquake shaking than are shallow tunnels.</li> <li>Underground facilities constructed in soils can be expected to suffer more damage compared to openings constructed in competent rock.</li> <li>Lined and grouted tunnels are safer than unlined tunnels in rock. Shaking damage can be reduced by stabilizing the ground around the tunnel and by improving the contact between the lining and the surrounding ground through grouting.</li> <li>Tunnels are more stable under a symmetric load, which improves ground-lining interaction. Improving the tunnel lining by placing thicker and stiffer sections without stabilizing surrounding poor ground may result in excess seismic forces in the lining. Backfilling with non-cyclically mobile material<sup class="noprint Inline-Template" style="margin-left:0.1em; white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Please_clarify" title="Wikipedia:Please clarify"><span title="The text near this tag may need clarification or removal of jargon. (October 2021)">clarification needed</span></a></i>]</sup> and rock-stabilizing measures may improve the safety and stability of shallow tunnels.</li> <li>Damage may be related to peak ground acceleration and velocity based on the magnitude and epicentral distance of the affected earthquake.</li> <li>Duration of strong-motion shaking during earthquakes is of utmost importance because it may cause fatigue failure and therefore, large deformations.</li> <li>High frequency motions may explain the local spalling of rock or concrete along planes of weakness. These frequencies, which rapidly attenuate with distance, may be expected mainly at small distances from the causative fault.</li> <li><a href="/wiki/Ground_motion" title="Ground motion">Ground motion</a> may be amplified upon incidence with a tunnel if wavelengths are between one and four times the tunnel diameter.</li> <li>Damage at and near tunnel portals may be significant due to slope instability.<sup id="cite_ref-55" class="reference"><a href="#cite_note-55"><span class="cite-bracket">[</span>55<span class="cite-bracket">]</span></a></sup></li></ul> <p>Earthquakes are one of nature's most formidable threats. A magnitude 6.7 earthquake shook the San Fernando valley in Los Angeles in 1994. The earthquake caused extensive damage to various structures, including buildings, freeway overpasses and road systems throughout the area. The National Center for Environmental Information estimates total damages to be 40 billion dollars.<sup id="cite_ref-56" class="reference"><a href="#cite_note-56"><span class="cite-bracket">[</span>56<span class="cite-bracket">]</span></a></sup> According to an article issued by Steve Hymon of TheSource – Transportation News and Views, there was no serious damage sustained by the LA subway system. Metro, the owner of the LA subway system, issued a statement through their engineering staff about the design and consideration that goes into a tunnel system. Engineers and architects perform extensive analysis as to how hard they expect earthquakes to hit that area. All of this goes into the overall design and flexibility of the tunnel. </p><p>This same trend of limited subway damage following an earthquake can be seen in many other places. In 1985 a magnitude 8.1 earthquake shook Mexico City; there was no damage to the subway system, and in fact the subway systems served as a lifeline for emergency personnel and evacuations. A magnitude 7.2 ripped through Kobe Japan in 1995, leaving no damage to the tunnels themselves. Entry portals sustained minor damages, however these damages were attributed to inadequate earthquake design that originated from the original construction date of 1965. In 2010 a magnitude 8.8, massive by any scale, afflicted Chile. Entrance stations to subway systems suffered minor damages, and the subway system was down for the rest of the day. By the next afternoon, the subway system was operational again.<sup id="cite_ref-57" class="reference"><a href="#cite_note-57"><span class="cite-bracket">[</span>57<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Examples">Examples</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=24" title="Edit section: Examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444"><table class="box-Cleanup plainlinks metadata ambox ambox-style ambox-Cleanup" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/40px-Edit-clear.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/60px-Edit-clear.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/f/f2/Edit-clear.svg/80px-Edit-clear.svg.png 2x" data-file-width="48" data-file-height="48" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section may <b>require <a href="/wiki/Wikipedia:Cleanup" title="Wikipedia:Cleanup">cleanup</a></b> to meet Wikipedia's <a href="/wiki/Wikipedia:Manual_of_Style" title="Wikipedia:Manual of Style">quality standards</a>. The specific problem is: <b>just a random list.</b><span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Tunnel" title="Special:EditPage/Tunnel">improve this section</a> if you can.</span> <span class="date-container"><i>(<span class="date">December 2017</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="In_history">In history</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=25" title="Edit section: In history"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/History_of_rapid_transit" title="History of rapid transit">History of rapid transit</a></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1251242444"><table class="box-More_citations_needed_section plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This section <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Tunnel" title="Special:EditPage/Tunnel">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a> in this section. Unsourced material may be challenged and removed.</span> <span class="date-container"><i>(<span class="date">March 2013</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Dudley_Canal_Tunnel_Southern_Portal.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Dudley_Canal_Tunnel_Southern_Portal.jpg/220px-Dudley_Canal_Tunnel_Southern_Portal.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Dudley_Canal_Tunnel_Southern_Portal.jpg/330px-Dudley_Canal_Tunnel_Southern_Portal.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/2a/Dudley_Canal_Tunnel_Southern_Portal.jpg/440px-Dudley_Canal_Tunnel_Southern_Portal.jpg 2x" data-file-width="3888" data-file-height="2592" /></a><figcaption>Southern portal of the 1791 Dudley Canal tunnel in England</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Entrance_of_the_Railway_at_Edge_Hill,_from_Bury%27s_Liverpool_and_Manchester_Railway,_1831_-_artfinder_122456.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/69/Entrance_of_the_Railway_at_Edge_Hill%2C_from_Bury%27s_Liverpool_and_Manchester_Railway%2C_1831_-_artfinder_122456.jpg/220px-Entrance_of_the_Railway_at_Edge_Hill%2C_from_Bury%27s_Liverpool_and_Manchester_Railway%2C_1831_-_artfinder_122456.jpg" decoding="async" width="220" height="177" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/69/Entrance_of_the_Railway_at_Edge_Hill%2C_from_Bury%27s_Liverpool_and_Manchester_Railway%2C_1831_-_artfinder_122456.jpg/330px-Entrance_of_the_Railway_at_Edge_Hill%2C_from_Bury%27s_Liverpool_and_Manchester_Railway%2C_1831_-_artfinder_122456.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/69/Entrance_of_the_Railway_at_Edge_Hill%2C_from_Bury%27s_Liverpool_and_Manchester_Railway%2C_1831_-_artfinder_122456.jpg/440px-Entrance_of_the_Railway_at_Edge_Hill%2C_from_Bury%27s_Liverpool_and_Manchester_Railway%2C_1831_-_artfinder_122456.jpg 2x" data-file-width="1024" data-file-height="826" /></a><figcaption><a href="/wiki/Thomas_Talbot_Bury" title="Thomas Talbot Bury">Thomas Talbot Bury</a>'s watercolour of the Liverpool Edge Hill tunnel portals</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Start_of_Lime_Street_Tunnel_Cutting.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/30/Start_of_Lime_Street_Tunnel_Cutting.jpg/220px-Start_of_Lime_Street_Tunnel_Cutting.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/30/Start_of_Lime_Street_Tunnel_Cutting.jpg/330px-Start_of_Lime_Street_Tunnel_Cutting.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/30/Start_of_Lime_Street_Tunnel_Cutting.jpg/440px-Start_of_Lime_Street_Tunnel_Cutting.jpg 2x" data-file-width="1984" data-file-height="1488" /></a><figcaption>A short section remains of the 1832 Edge Hill to Lime Street tunnel in <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a>. This and a short section of the original tunnel nearer to Lime Street are the oldest rail tunnels in the world still in active use.</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg/220px-Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg/330px-Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/ad/Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg/440px-Leaving_Liverpool_Lime_St_-_geograph.org.uk_-_747034.jpg 2x" data-file-width="640" data-file-height="480" /></a><figcaption><a href="/wiki/Liverpool_Lime_Street_railway_station" title="Liverpool Lime Street railway station">Liverpool Lime Street</a> Approach. The original two-track tunnel was removed to create a deep cutting. Some of the road bridges seen across the cutting are solid rock and in effect are a series of short tunnels.</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Edge_Hill_cutting.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Edge_Hill_cutting.jpg/220px-Edge_Hill_cutting.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Edge_Hill_cutting.jpg/330px-Edge_Hill_cutting.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Edge_Hill_cutting.jpg/440px-Edge_Hill_cutting.jpg 2x" data-file-width="4000" data-file-height="3000" /></a><figcaption>The three eastern portals of Liverpool Edge Hill tunnels, built into a hand-dug deep cutting. The left tunnel with tracks is the short 1846 second Crown Street Tunnel, still used for shunting. In the center, partially hidden by undergrowth, is the disused 2.03 km (1.26 mi) 1829 <a href="/wiki/Wapping_Tunnel" title="Wapping Tunnel">Wapping Tunnel</a>. On the right, hidden by undergrowth, is the disused original short 1829 Crown Street Tunnel.</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Donner_Pass_Summit_Tunnel_West_Portal.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Donner_Pass_Summit_Tunnel_West_Portal.jpg/220px-Donner_Pass_Summit_Tunnel_West_Portal.jpg" decoding="async" width="220" height="272" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Donner_Pass_Summit_Tunnel_West_Portal.jpg/330px-Donner_Pass_Summit_Tunnel_West_Portal.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Donner_Pass_Summit_Tunnel_West_Portal.jpg/440px-Donner_Pass_Summit_Tunnel_West_Portal.jpg 2x" data-file-width="700" data-file-height="864" /></a><figcaption>The 1,659-foot (506 m) <a href="/wiki/Donner_Pass" title="Donner Pass">Donner Pass</a> Summit Tunnel (#6) was in service from 1868 to 1993.</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Sommeiller_drill.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Sommeiller_drill.jpg/220px-Sommeiller_drill.jpg" decoding="async" width="220" height="119" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Sommeiller_drill.jpg/330px-Sommeiller_drill.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Sommeiller_drill.jpg/440px-Sommeiller_drill.jpg 2x" data-file-width="794" data-file-height="428" /></a><figcaption>A late 19th-century pneumatic rock-drilling machine, invented by <a href="/wiki/Germain_Sommeiller" title="Germain Sommeiller">Germain Sommeiller</a> and used to drill the first large tunnels through the <a href="/wiki/Alps" title="Alps">Alps</a></figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Small_operational_brick_tunnel.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Small_operational_brick_tunnel.JPG/220px-Small_operational_brick_tunnel.JPG" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Small_operational_brick_tunnel.JPG/330px-Small_operational_brick_tunnel.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f6/Small_operational_brick_tunnel.JPG/440px-Small_operational_brick_tunnel.JPG 2x" data-file-width="1600" data-file-height="1068" /></a><figcaption>Small operational brick tunnel in France</figcaption></figure> <p>The history of ancient tunnels and tunneling in the world is reviewed in various sources which include many examples of these structures that were built for different purposes.<sup id="cite_ref-58" class="reference"><a href="#cite_note-58"><span class="cite-bracket">[</span>58<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-59" class="reference"><a href="#cite_note-59"><span class="cite-bracket">[</span>59<span class="cite-bracket">]</span></a></sup> Some well known ancient and modern tunnels are briefly introduced below: </p> <ul><li>The <a href="/wiki/Qanat" title="Qanat">qanat</a> or <a href="/wiki/Kareez" class="mw-redirect" title="Kareez">kareez</a> of <a href="/wiki/Persia" class="mw-redirect" title="Persia">Persia</a> are water management systems used to provide a reliable supply of water to human settlements or for irrigation in hot, arid and semi-arid climates. The deepest known qanat is in the Iranian city of <a href="/wiki/Gonabad" title="Gonabad">Gonabad</a>, which after 2700 years, still provides drinking and agricultural water to nearly 40,000 people. Its main well depth is more than 360 m (1,180 ft), and its length is 45 km (28 mi).<sup id="cite_ref-60" class="reference"><a href="#cite_note-60"><span class="cite-bracket">[</span>60<span class="cite-bracket">]</span></a></sup></li> <li>The <a href="/wiki/Siloam_Tunnel" class="mw-redirect" title="Siloam Tunnel">Siloam Tunnel</a> was built before 701 BC for a reliable supply of water, to withstand <a href="/wiki/Siege" title="Siege">siege</a> attacks.</li> <li>The <a href="/wiki/Eupalinian_aqueduct" class="mw-redirect" title="Eupalinian aqueduct">Eupalinian aqueduct</a> on the island of <a href="/wiki/Samos_Island" class="mw-redirect" title="Samos Island">Samos</a> (<a href="/wiki/North_Aegean" title="North Aegean">North Aegean</a>, Greece) was built in 520 BC by the ancient Greek engineer <a href="/wiki/Eupalinos" title="Eupalinos">Eupalinos</a> of <a href="/wiki/Megara" title="Megara">Megara</a> under a contract with the local community. Eupalinos organised the work so that the tunnel was begun from both sides of Mount Kastro. The two teams advanced simultaneously and met in the middle with excellent accuracy, something that was extremely difficult in that time. The aqueduct was of utmost defensive importance, since it ran underground, and it was not easily found by an enemy who could otherwise cut off the water supply to <a href="/wiki/Pythagoreion" title="Pythagoreion">Pythagoreion</a>, the ancient capital of <a href="/wiki/Samos_Island" class="mw-redirect" title="Samos Island">Samos</a>. The tunnel's existence was recorded by Herodotus (as was the mole and harbour, and the third wonder of the island, the great temple to Hera, thought by many to be the largest in the Greek world). The precise location of the tunnel was only re-established in the 19th century by German archaeologists. The tunnel proper is 1,030 m long (3,380 ft) and visitors can still enter it.</li> <li>One of the first known drainage and sewage networks in form of <a href="/wiki/Drainage_tunnel" title="Drainage tunnel">tunnels</a> was constructed at Persepolis in Iran at the same time as the construction of its foundation in 518 BC. In most places the network was dug in the sound rock of the mountain and then covered by large pieces of rock and stone followed by earth and piles of rubble to level the ground. During investigations and surveys, long sections of similar rock tunnels extending beneath the palace area were traced by Herzfeld and later by Schmidt and their archeological teams.<sup id="cite_ref-61" class="reference"><a href="#cite_note-61"><span class="cite-bracket">[</span>61<span class="cite-bracket">]</span></a></sup></li> <li>The <a href="/wiki/Via_Flaminia" title="Via Flaminia">Via Flaminia</a>, an important <a href="/wiki/Roman_road" class="mw-redirect" title="Roman road">Roman road</a>, penetrated the <a href="/wiki/Furlo" class="mw-redirect" title="Furlo">Furlo</a> pass in the <a href="/wiki/Apennines" class="mw-redirect" title="Apennines">Apennines</a> through a tunnel which emperor <a href="/wiki/Vespasian" title="Vespasian">Vespasian</a> had ordered built in 76–77 AD. A modern road, the SS 3 Flaminia, still uses this tunnel, which had a precursor dating back to the 3rd century BC, remnants of this earlier tunnel (one of the first road tunnels) are also still visible.</li> <li>The world's oldest tunnel traversing under a water body is claimed<sup id="cite_ref-62" class="reference"><a href="#cite_note-62"><span class="cite-bracket">[</span>62<span class="cite-bracket">]</span></a></sup> to be the <i>Terelek kaya tüneli</i> under <a href="/wiki/K%C4%B1z%C4%B1l_River" class="mw-redirect" title="Kızıl River">Kızıl River</a>, a little south of the towns of <a href="/wiki/Boyabat" title="Boyabat">Boyabat</a> and <a href="/wiki/Dura%C4%9Fan" title="Durağan">Durağan</a> in <a href="/wiki/Turkey" title="Turkey">Turkey</a>, just downstream from where <a href="/wiki/Kizil_River" class="mw-redirect" title="Kizil River">Kizil River</a> joins its tributary <a href="/wiki/G%C3%B6k%C4%B1rmak" class="mw-redirect" title="Gökırmak">Gökırmak</a>. The tunnel is presently under a narrow part of a lake formed by a dam some kilometers further downstream. Estimated to have been built more than 2000 years ago, possibly by the same civilization that also built the royal tombs in a rock face nearby, it is assumed to have had a defensive purpose.</li> <li><a href="/wiki/Sapperton_Canal_Tunnel" title="Sapperton Canal Tunnel">Sapperton Canal Tunnel</a> on the <a href="/wiki/Thames_and_Severn_Canal" title="Thames and Severn Canal">Thames and Severn Canal</a> in <a href="/wiki/England" title="England">England</a>, dug through hills, which opened in 1789, was 3.5 km (2.2 mi) long and allowed <a href="/wiki/Barge" title="Barge">boat</a> transport of <a href="/wiki/Coal" title="Coal">coal</a> and other goods. Above it the <a href="/wiki/Sapperton_railway_tunnel" class="mw-redirect" title="Sapperton railway tunnel">Sapperton Long Tunnel</a> was constructed which carries the "Golden Valley" railway line between <a href="/wiki/Swindon" title="Swindon">Swindon</a> and <a href="/wiki/Gloucester" title="Gloucester">Gloucester</a>.</li> <li>The 1791 <a href="/wiki/Dudley_Tunnel" title="Dudley Tunnel">Dudley canal tunnel</a> is on the <a href="/wiki/Dudley_Canal" title="Dudley Canal">Dudley Canal</a>, in <a href="/wiki/Dudley" title="Dudley">Dudley</a>, <a href="/wiki/England" title="England">England</a>. The tunnel is 2.9 kilometres (1.83 mi) long. Closed in 1962 the tunnel was reopened in 1973. The series of tunnels was extended in 1984 and 1989.<sup id="cite_ref-63" class="reference"><a href="#cite_note-63"><span class="cite-bracket">[</span>63<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Fritchley_Tunnel" title="Fritchley Tunnel">Fritchley Tunnel</a>, constructed in 1793 in Derbyshire by the <a href="/wiki/Butterley_Company" title="Butterley Company">Butterley Company</a> to transport limestone to its ironworks factory. The Butterley company engineered and built its own railway. A victim of the depression the company closed after 219 years in 2009. The tunnel is the world's oldest railway tunnel traversed by rail wagons. Gravity and horse haulage was utilised. The railway was converted to steam locomotion in 1813 using a <a href="/wiki/Steam_Horse_locomotive" title="Steam Horse locomotive">Steam Horse locomotive</a> engineered and built by the Butterley company, however reverted to horses. Steam trains used the tunnel continuously from the 1840s when the railway was converted to a narrow gauge. The line closed in 1933. In the Second World War, the tunnel was used as an air raid shelter. Sealed up in 1977 it was rediscovered in 2013 and inspected. The tunnel was resealed to preserved the construction as it was designated an ancient monument.<sup id="cite_ref-listedbuilding1422984_64-0" class="reference"><a href="#cite_note-listedbuilding1422984-64"><span class="cite-bracket">[</span>64<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-BBC22342239_65-0" class="reference"><a href="#cite_note-BBC22342239-65"><span class="cite-bracket">[</span>65<span class="cite-bracket">]</span></a></sup></li> <li>The 1794 <a href="/wiki/Butterley_Tunnel" title="Butterley Tunnel">Butterley canal tunnel</a> canal tunnel is 2,819 m (1.8 mi) in length on the <a href="/wiki/Cromford_Canal" title="Cromford Canal">Cromford Canal</a> in <a href="/wiki/Ripley,_Derbyshire" title="Ripley, Derbyshire">Ripley, Derbyshire</a>, England. The tunnel was built simultaneously with the 1793 Fritchley railway tunnel. The tunnel partially collapsed in 1900 splitting the Cromford Canal, and has not been used since. The Friends of Cromford Canal, a group of volunteers, are working at fully restoring the Cromford Canal and the Butterley Tunnel.<sup id="cite_ref-66" class="reference"><a href="#cite_note-66"><span class="cite-bracket">[</span>66<span class="cite-bracket">]</span></a></sup></li> <li>The 1796 Stoddart Tunnel in Chapel-en-le-Frith in <a href="/wiki/Derbyshire" title="Derbyshire">Derbyshire</a> is reputed to be the oldest rail tunnel in the world. The rail wagons were originally horse-drawn.</li> <li><a href="/wiki/Smuggling_tunnel#Derby_Tunnels" title="Smuggling tunnel">Derby Tunnels</a> in <a href="/wiki/Salem,_Massachusetts" title="Salem, Massachusetts">Salem, Massachusetts</a>, were built in 1801 to smuggle imports affected by President <a href="/wiki/Thomas_Jefferson" title="Thomas Jefferson">Thomas Jefferson</a>'s new customs duties. Jefferson had ordered local militias to help the Custom House in each port collect these dues, but the smugglers, led by Elias Derby, hired the Salem militia to dig the tunnels and hide the spoil.</li> <li>A tunnel was created for the first true steam locomotive, from <a href="/wiki/Penydarren" title="Penydarren">Penydarren</a> to <a href="/wiki/Abercynon" title="Abercynon">Abercynon</a>. The Penydarren locomotive was built by <a href="/wiki/Richard_Trevithick" title="Richard Trevithick">Richard Trevithick</a>. The locomotive made the historic journey from Penydarren to Abercynon in 1804. Part of this tunnel can still be seen at <a href="/wiki/Pentrebach" title="Pentrebach">Pentrebach</a>, <a href="/wiki/Merthyr_Tydfil" title="Merthyr Tydfil">Merthyr Tydfil</a>, <a href="/wiki/Wales" title="Wales">Wales</a>. This is arguably the oldest railway tunnel in the world, dedicated only to self-propelled steam engines on rails.</li> <li>The <a href="/wiki/Montgomery_Bell_Tunnel" title="Montgomery Bell Tunnel">Montgomery Bell Tunnel</a> in Tennessee, an 88 m long (289 ft) water diversion tunnel, 4.50 m × 2.45 m high (14.8 ft × 8.0 ft), to power a water wheel, was built by slave labour in 1819, being the first full-scale tunnel in North America.</li> <li>Bourne's Tunnel, <a href="/wiki/Rainhill" title="Rainhill">Rainhill</a>, near <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a>, England. It is 32.1 m (105 ft) long. Built in the late 1820s, the exact date is unknown, however probably built in 1828 or 1829. This is the first tunnel in the world constructed under a railway line. The construction of the Liverpool to Manchester Railway ran over a horse-drawn tramway that ran from the Sutton collieries to the Liverpool-Warrington turnpike road. A tunnel was bored under the railway for the tramway. As the railway was being constructed the tunnel was made operational, opening prior to the Liverpool tunnels on the Liverpool to Manchester line. The tunnel was made redundant in 1844 when the tramway was dismantled.<sup id="cite_ref-67" class="reference"><a href="#cite_note-67"><span class="cite-bracket">[</span>67<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Crown_Street_railway_station" title="Crown Street railway station">Crown Street station</a>, <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a>, England, 1829. Built by <a href="/wiki/George_Stephenson" title="George Stephenson">George Stephenson</a>, a single track railway tunnel 266 m long (873 ft), was bored from Edge Hill to Crown Street to serve the world's first intercity passenger railway terminus station. The station was abandoned in 1836 being too far from Liverpool city centre, with the area converted for freight use. Closed down in 1972, the tunnel is disused. However it is the oldest passenger rail tunnel running under streets in the world.<sup id="cite_ref-68" class="reference"><a href="#cite_note-68"><span class="cite-bracket">[</span>68<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-subbrit.org.uk_69-0" class="reference"><a href="#cite_note-subbrit.org.uk-69"><span class="cite-bracket">[</span>69<span class="cite-bracket">]</span></a></sup></li> <li>The 1829 <a href="/wiki/Wapping_Tunnel" title="Wapping Tunnel">Wapping Tunnel</a> in Liverpool, England, at 2.03 km (1.26 mi) long on a twin track railway, was the first rail tunnel bored under a metropolis. The tunnel's path is from Edge Hill in the east of the city to <a href="/wiki/Wapping_Dock" title="Wapping Dock">Wapping Dock</a> in the south end Liverpool docks. The tunnel was used only for freight terminating at the <a href="/wiki/Park_Lane_railway_goods_station" title="Park Lane railway goods station">Park Lane goods terminal</a>. Currently disused since 1972, the tunnel was to be a part of the <a href="/wiki/Merseyrail" title="Merseyrail">Merseyrail</a> metro network, with work started and abandoned because of costs. The tunnel is in excellent condition and is still being considered for reuse by Merseyrail, maybe with an underground station cut into the tunnel for Liverpool university. The river portal is opposite the new <a href="/wiki/Echo_Arena_Liverpool" class="mw-redirect" title="Echo Arena Liverpool">King's Dock Liverpool Arena</a> being an ideal location for a serving station. If reused the tunnel will be the oldest used underground rail tunnel in the world and oldest section of any underground metro system.<sup id="cite_ref-subbrit.org.uk_69-1" class="reference"><a href="#cite_note-subbrit.org.uk-69"><span class="cite-bracket">[</span>69<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-70" class="reference"><a href="#cite_note-70"><span class="cite-bracket">[</span>70<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-maund_71-0" class="reference"><a href="#cite_note-maund-71"><span class="cite-bracket">[</span>71<span class="cite-bracket">]</span></a></sup></li> <li>1832, <a href="/wiki/Liverpool_Lime_Street_railway_station" title="Liverpool Lime Street railway station">Lime Street railway station</a> tunnel, Liverpool. A two track rail tunnel, 1.811 km (1.125 mi) long was bored under the metropolis from Edge Hill in the east of the city to Lime Street in Liverpool's city centre. The tunnel was in use from 1832 being used to transport building materials to the new Lime St station while under construction. The station and tunnel was opened to passengers in 1836. In the 1880s the tunnel was converted to a deep cutting, open to the atmosphere, being four tracks wide. This is the only occurrence of a major tunnel being removed. Two short sections of the original tunnel still exist at Edge Hill station and further towards Lime Street, giving the two tunnels the distinction of being the oldest rail tunnels in the world still in use, and the oldest in use under streets.<sup id="cite_ref-72" class="reference"><a href="#cite_note-72"><span class="cite-bracket">[</span>72<span class="cite-bracket">]</span></a></sup> Over time a 525 m (0.326 mi) section of the deep cutting has been converted back into tunnel due to sections having buildings built over.</li> <li><a href="/wiki/Box_Tunnel" title="Box Tunnel">Box Tunnel</a> in England, which opened in 1841, was the longest railway tunnel in the world at the time of construction. It was dug by hand, and has a length of 2.9 km (1.8 mi).</li> <li>The 1.1 km (0.68 mi) 1842 Prince of Wales Tunnel, in <a href="/wiki/Shildon" title="Shildon">Shildon</a> near Darlington, England, is the oldest sizeable tunnel in the world still in use under a settlement.</li> <li>The <a href="/wiki/Victoria_Tunnel_(Newcastle)" title="Victoria Tunnel (Newcastle)">Victoria Tunnel Newcastle</a> opened in 1842, is a 3.9-kilometre (2.4 mi) subterranean wagonway with a maximum depth of 26 metres (85 ft) that drops 222 feet (68 m) from entrance to exit. The tunnel runs under Newcastle upon Tyne, England, and originally exited at the River Tyne. It remains largely intact. Originally designed to carry coal from <a href="/wiki/Spital_Tongues" title="Spital Tongues">Spital Tongues</a> to the river, in WW2 part of the tunnel was used as a shelter. Under the management of a charitable foundation called the Ouseburn Trust it is currently used for heritage tours.</li> <li>The <a href="/wiki/Thames_Tunnel" title="Thames Tunnel">Thames Tunnel</a>, built by <a href="/wiki/Marc_Isambard_Brunel" title="Marc Isambard Brunel">Marc Isambard Brunel</a> and his son <a href="/wiki/Isambard_Kingdom_Brunel" title="Isambard Kingdom Brunel">Isambard Kingdom Brunel</a> opened in 1843, was the first tunnel (after Terelek) traversing under a water body, and the first to be built using a <a href="/wiki/Tunnelling_shield" title="Tunnelling shield">tunnelling shield</a>. Originally used as a foot-tunnel, the tunnel was converted to a railway tunnel in 1869 and was a part of the <a href="/wiki/East_London_Line" class="mw-redirect" title="East London Line">East London Line</a> of the <a href="/wiki/London_Underground" title="London Underground">London Underground</a> until 2007. It was the oldest section of the network, although not the oldest purpose built rail section. From 2010 the tunnel became a part of the <a href="/wiki/London_Overground" title="London Overground">London Overground</a> network.</li> <li>The 3.34 km (2.08 mi) <a href="/wiki/Victoria_Tunnel_(Liverpool)" title="Victoria Tunnel (Liverpool)">Victoria Tunnel</a>/<a href="/wiki/Waterloo_Tunnel" title="Waterloo Tunnel">Waterloo Tunnel</a> in <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a>, England, was bored under a metropolis opening in 1848. The tunnel was initially used only for rail freight serving the Waterloo Freight terminal, and later freight and passengers serving the <a href="/wiki/Liverpool_Riverside_railway_station" title="Liverpool Riverside railway station">Liverpool ship liner terminal</a>. The tunnel's path is from Edge Hill in the east of the city to the north end Liverpool docks at <a href="/wiki/Waterloo_Dock_(Liverpool)" class="mw-redirect" title="Waterloo Dock (Liverpool)">Waterloo Dock</a>. The tunnel is split into two tunnels with a short open air cutting linking the two. The cutting is where the cable hauled trains from Edge Hill were hitched and unhitched. The two tunnels are effectively one on the same centre line and are regarded as one. However, as initially the 2,375 m (1.476 mi) long Victoria section was originally cable hauled and the shorter 862 m (943 yd) Waterloo section was locomotive hauled, two separate names were given, the short section was named the <a href="/wiki/Waterloo_Tunnel" title="Waterloo Tunnel">Waterloo Tunnel</a>. In 1895 the two tunnels were converted to locomotive haulage. Used until 1972, the tunnel is still in excellent condition. A short section of the Victoria tunnel at Edge Hill is still used for shunting trains. The tunnel is being considered for reuse by the <a href="/wiki/Merseyrail" title="Merseyrail">Merseyrail</a> network. Stations cut into the tunnel are being considered and also reuse by a monorail system from the proposed <a href="/wiki/Liverpool_Waters" title="Liverpool Waters">Liverpool Waters</a> redevelopment of Liverpool's Central Docks has been proposed.<sup id="cite_ref-73" class="reference"><a href="#cite_note-73"><span class="cite-bracket">[</span>73<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-74" class="reference"><a href="#cite_note-74"><span class="cite-bracket">[</span>74<span class="cite-bracket">]</span></a></sup></li> <li>The summit tunnel of the <a href="/wiki/Semmering_railway" title="Semmering railway">Semmering railway</a>, the first Alpine tunnel, was opened in 1848 and was 1.431 km (0.889 mi) long. It connected rail traffic between <a href="/wiki/Vienna" title="Vienna">Vienna</a>, the capital of <a href="/wiki/Austro-Hungarian_Empire" class="mw-redirect" title="Austro-Hungarian Empire">Austro-Hungarian Empire</a>, and <a href="/wiki/Trieste" title="Trieste">Trieste</a>, its port.</li> <li>The <a href="/w/index.php?title=Giovi_Rail_Tunnel&action=edit&redlink=1" class="new" title="Giovi Rail Tunnel (page does not exist)">Giovi Rail Tunnel</a> through the <a href="/wiki/Appennini" class="mw-redirect" title="Appennini">Appennini</a> Mounts opened in 1854, linking the capital city of the <a href="/wiki/Kingdom_of_Sardinia" title="Kingdom of Sardinia">Kingdom of Sardinia</a>, <a href="/wiki/Turin" title="Turin">Turin</a>, to its port, <a href="/wiki/Genoa" title="Genoa">Genoa</a>. The tunnel was 3.25 km (2.02 mi) long.</li> <li>The oldest underground sections of the <a href="/wiki/London_Underground" title="London Underground">London Underground</a> were built using the cut-and-cover method in the 1860s, and opened in January 1863. What are now the <a href="/wiki/Metropolitan_line" title="Metropolitan line">Metropolitan</a>, Hammersmith & City and Circle lines were the first to prove the success of a <a href="/wiki/Rapid_transit" title="Rapid transit">metro</a> or subway system.</li> <li>On 18 June 1868, the <a href="/wiki/Central_Pacific_Railroad" title="Central Pacific Railroad">Central Pacific Railroad</a>'s 506-metre (1,659 ft) Summit Tunnel (Tunnel #6) at <a href="/wiki/Donner_Pass" title="Donner Pass">Donner Pass</a> in the California <a href="/wiki/Sierra_Nevada_(U.S.)" class="mw-redirect" title="Sierra Nevada (U.S.)">Sierra Nevada</a> mountains was opened, permitting the establishment of the commercial mass transportation of passengers and freight over the Sierras for the first time. It remained in daily use until 1993, when the <a href="/wiki/Southern_Pacific_Railroad" class="mw-redirect" title="Southern Pacific Railroad">Southern Pacific Railroad</a> closed it and transferred all rail traffic through the 3,146-metre (10,322 ft) long Tunnel #41 (a.k.a. "The Big Hole") built a mile to the south in 1925.</li> <li>In 1870, after fourteen years of works, the <a href="/wiki/Fr%C3%A9jus_Rail_Tunnel" title="Fréjus Rail Tunnel">Fréjus Rail Tunnel</a> was completed between France and Italy, being the second-oldest Alpine tunnel, 13.7 km (8.5 mi) long. At that time it was the longest in the world.</li> <li>The third Alpine tunnel, the <a href="/wiki/Gotthard_Rail_Tunnel" class="mw-redirect" title="Gotthard Rail Tunnel">Gotthard Rail Tunnel</a>, between northern and southern Switzerland, opened in 1882 and was the longest rail tunnel in the world, measuring 15 km (9.3 mi).</li> <li>The 1882 <a href="/wiki/Col_de_Tende_Road_Tunnel" title="Col de Tende Road Tunnel">Col de Tende Road Tunnel</a>, at 3.182 km (1.977 mi) long, was one of the first long road tunnels under a pass, running between France and Italy.</li> <li>The <a href="/wiki/Mersey_Railway" title="Mersey Railway">Mersey Railway</a> tunnel opened in 1886, running from Liverpool to Birkenhead under the River Mersey. The <a href="/wiki/Mersey_Railway" title="Mersey Railway">Mersey Railway</a> was the world's first deep-level underground railway. By 1892 the extensions on land from Birkenhead Park station to Liverpool Central Low level station gave a tunnel 5.02 km (3.12 mi) in length. The under river section is 1.21 km (0.75 mi) in length, and was the longest underwater tunnel in world in January 1886.<sup id="cite_ref-75" class="reference"><a href="#cite_note-75"><span class="cite-bracket">[</span>75<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-76" class="reference"><a href="#cite_note-76"><span class="cite-bracket">[</span>76<span class="cite-bracket">]</span></a></sup></li> <li>The rail <a href="/wiki/Severn_Tunnel" title="Severn Tunnel">Severn Tunnel</a> was opened in late 1886, at 7.008 km (4.355 mi) long, although only 3.62 km (2.25 mi) of the tunnel is actually under the River Severn. The tunnel replaced the Mersey Railway tunnel's longest under water record, which was held for less than a year.</li> <li><a href="/wiki/James_Greathead" class="mw-redirect" title="James Greathead">James Greathead</a>, in constructing the City & South London Railway tunnel beneath the Thames, opened in 1890, brought together three key elements of tunnel construction under water: <ol><li>shield method of excavation;</li> <li>permanent cast iron tunnel lining;</li> <li>construction in a compressed air environment to inhibit water flowing through soft ground material into the tunnel heading.<sup id="cite_ref-nrhp_stclair_77-0" class="reference"><a href="#cite_note-nrhp_stclair-77"><span class="cite-bracket">[</span>77<span class="cite-bracket">]</span></a></sup></li></ol></li> <li>Built in sections between 1890 and 1939, the section of London Underground's <a href="/wiki/Northern_line" title="Northern line">Northern line</a> from Morden to East Finchley via Bank was the longest railway tunnel in the world at 27.8 km (17.3 mi) in length.</li> <li><a href="/wiki/St._Clair_Tunnel" title="St. Clair Tunnel">St. Clair Tunnel</a>, also opened later in 1890, linked the elements of the Greathead tunnels on a larger scale.<sup id="cite_ref-nrhp_stclair_77-1" class="reference"><a href="#cite_note-nrhp_stclair-77"><span class="cite-bracket">[</span>77<span class="cite-bracket">]</span></a></sup></li> <li>In 1906 the fourth Alpine tunnel opened, the <a href="/wiki/Simplon_Tunnel" title="Simplon Tunnel">Simplon Tunnel</a>, between Switzerland and Italy. It is 19.8 km (12.3 mi) long, and was the longest tunnel in the world until 1982. It was also the deepest tunnel in the world, with a maximum rock overlay of approximately 2,150 m (7,050 ft).</li> <li>The 1927 <a href="/wiki/Holland_Tunnel" title="Holland Tunnel">Holland Tunnel</a> was the first underwater tunnel designed for automobiles. The construction required a novel <a href="/wiki/Holland_Tunnel#Ventilation_system" title="Holland Tunnel">ventilation system</a>.</li> <li>In 1945 the <a href="/wiki/Delaware_Aqueduct" title="Delaware Aqueduct">Delaware Aqueduct</a> tunnel was completed, supplying water to New York City. At 137 km (85 mi) it is the longest tunnel in the world.</li> <li>In 1988 the 53.850 km (33.461 mi) long <a href="/wiki/Seikan_Tunnel" title="Seikan Tunnel">Seikan Tunnel</a> in Japan was completed under the <a href="/wiki/Tsugaru_Strait" title="Tsugaru Strait">Tsugaru Strait</a>, linking the islands of <a href="/wiki/Honshu" title="Honshu">Honshu</a> and <a href="/wiki/Hokkaido" title="Hokkaido">Hokkaido</a>. It was the longest railway tunnel in the world at that time.</li> <li><a href="/wiki/Ryfast" title="Ryfast">Ryfast</a> is the longest undersea road tunnel. It is 14.3 km (8.9 mi) in length.<sup id="cite_ref-78" class="reference"><a href="#cite_note-78"><span class="cite-bracket">[</span>78<span class="cite-bracket">]</span></a></sup> The tunnel opened for use in 2020.</li></ul> <div class="mw-heading mw-heading3"><h3 id="Longest">Longest</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=26" title="Edit section: Longest"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/List_of_longest_tunnels" title="List of longest tunnels">List of longest tunnels</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Gotthard_Base_Tunnel.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/45/Gotthard_Base_Tunnel.jpg/220px-Gotthard_Base_Tunnel.jpg" decoding="async" width="220" height="147" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/45/Gotthard_Base_Tunnel.jpg/330px-Gotthard_Base_Tunnel.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/45/Gotthard_Base_Tunnel.jpg/440px-Gotthard_Base_Tunnel.jpg 2x" data-file-width="3855" data-file-height="2570" /></a><figcaption>The Gotthard Base Tunnel is the first flat route through a major mountain range.</figcaption></figure> <ul><li>The <a href="/wiki/Thirlmere_Aqueduct" title="Thirlmere Aqueduct">Thirlmere Aqueduct</a> in <a href="/wiki/North_West_England" title="North West England">North West England</a>, United Kingdom is sometimes considered the longest tunnel, of any type, in the world at 154 km (96 mi), though the aqueduct's tunnel section is not continuous.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Accuracy_dispute#Disputed_statement" title="Wikipedia:Accuracy dispute"><span title="The material near this tag is possibly inaccurate or nonfactual. (March 2014)">dubious</span></a> – <a href="/wiki/Talk:Tunnel#Dubious" title="Talk:Tunnel">discuss</a></i>]</sup></li> <li>The <a href="/wiki/Dahuofang_Water_Tunnel" title="Dahuofang Water Tunnel">Dahuofang Water Tunnel</a> in <a href="/wiki/China" title="China">China</a>, opened in 2009, is the third longest water tunnel in the world at 85.3 km (53.0 mi) length.</li> <li>The <a href="/wiki/Gotthard_Base_Tunnel" title="Gotthard Base Tunnel">Gotthard Base Tunnel</a> in <a href="/wiki/Switzerland" title="Switzerland">Switzerland</a>, opened in 2016, is the longest and deepest railway tunnel in the world at 57.1 km (35.5 mi) length and 2,450 m (8,040 ft) maximum depth below the <a href="/wiki/Saint-Gotthard_Massif" title="Saint-Gotthard Massif">Gotthard Massif</a>. It provides a <a href="/wiki/NRLA" title="NRLA">flat transit route</a> between the North and South of Europe under the <a href="/wiki/Swiss_Alps" title="Swiss Alps">Swiss Alps</a>, at a maximum elevation of 549 m (1,801 ft).</li> <li>The <a href="/wiki/Seikan_Tunnel" title="Seikan Tunnel">Seikan Tunnel</a> in <a href="/wiki/Japan" title="Japan">Japan</a> connects the main island of <a href="/wiki/Honshu" title="Honshu">Honshu</a> with the northern island of <a href="/wiki/Hokkaido" title="Hokkaido">Hokkaido</a> by rail. It is 53.9-kilometre (33.5 mi) long, of which 23.3 km (14.5 mi) are crossing the <a href="/wiki/Tsugaru_Strait" title="Tsugaru Strait">Tsugaru Strait</a> undersea.</li> <li>The <a href="/wiki/Channel_Tunnel" title="Channel Tunnel">Channel Tunnel</a> crosses the <a href="/wiki/English_Channel" title="English Channel">English Channel</a> between <a href="/wiki/France" title="France">France</a> and the <a href="/wiki/United_Kingdom" title="United Kingdom">United Kingdom</a>. It has a total length of 50 km (31 mi), of which 39 km (24 mi) are the world's longest undersea tunnel section.</li> <li>The <a href="/wiki/L%C3%B6tschberg_Base_Tunnel" title="Lötschberg Base Tunnel">Lötschberg Base Tunnel</a> in <a href="/wiki/Switzerland" title="Switzerland">Switzerland</a> was the longest land rail tunnel, with a length of 34.5 km (21.4 mi), from its inauguration in 2007 until the completion of the <a href="/wiki/Gotthard_Base_Tunnel" title="Gotthard Base Tunnel">Gotthard Base Tunnel</a> in 2016.</li> <li>The <a href="/wiki/L%C3%A6rdal_Tunnel" title="Lærdal Tunnel">Lærdal Tunnel</a> in Norway from <a href="/wiki/L%C3%A6rdal" title="Lærdal">Lærdal</a> to <a href="/wiki/Aurland" title="Aurland">Aurland</a> is the world's longest road tunnel, intended for cars and similar vehicles, at 24.5 km (15.2 mi).</li> <li>The <a href="/wiki/Zhongnanshan_Tunnel" title="Zhongnanshan Tunnel">Zhongnanshan Tunnel</a> in <a href="/wiki/People%27s_Republic_of_China" class="mw-redirect" title="People's Republic of China">People's Republic of China</a> opened in January 2007 is the world's second longest <a href="/wiki/Highway" title="Highway">highway</a> tunnel and the longest mountain road tunnel in Asia, at 18 km (11 mi).</li> <li>The longest canal tunnel is the <a href="/wiki/Rove_Tunnel" title="Rove Tunnel">Rove Tunnel</a> in France, over 7.12 km (4.42 mi) long.</li></ul> <div class="mw-heading mw-heading3"><h3 id="Notable">Notable</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=27" title="Edit section: Notable"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Tunnel-large.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/db/Tunnel-large.jpg/220px-Tunnel-large.jpg" decoding="async" width="220" height="102" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/db/Tunnel-large.jpg/330px-Tunnel-large.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/db/Tunnel-large.jpg/440px-Tunnel-large.jpg 2x" data-file-width="1024" data-file-height="474" /></a><figcaption>The <a href="/wiki/Big_Dig" title="Big Dig">Big Dig</a> road vehicle tunnel in <a href="/wiki/Boston" title="Boston">Boston</a>, U.S.</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Gerrards_Cross_railway_station_2.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/12/Gerrards_Cross_railway_station_2.jpg/220px-Gerrards_Cross_railway_station_2.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/12/Gerrards_Cross_railway_station_2.jpg/330px-Gerrards_Cross_railway_station_2.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/12/Gerrards_Cross_railway_station_2.jpg/440px-Gerrards_Cross_railway_station_2.jpg 2x" data-file-width="2032" data-file-height="1524" /></a><figcaption>The <a href="/wiki/Gerrards_Cross_tunnel" class="mw-redirect" title="Gerrards Cross tunnel">Gerrards Cross tunnel</a> in England, completed in 2010. Looking west towards the station in March 2005, showing the extent of construction three months before a small section collapsed.</figcaption></figure> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Sideling_Hill_Tunnel_2009.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Sideling_Hill_Tunnel_2009.jpg/220px-Sideling_Hill_Tunnel_2009.jpg" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Sideling_Hill_Tunnel_2009.jpg/330px-Sideling_Hill_Tunnel_2009.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Sideling_Hill_Tunnel_2009.jpg/440px-Sideling_Hill_Tunnel_2009.jpg 2x" data-file-width="1600" data-file-height="1200" /></a><figcaption>The eastern portal of the abandoned <a href="/wiki/Sideling_Hill_Tunnel" title="Sideling Hill Tunnel">Sideling Hill Tunnel</a>, Pennsylvania, U.S., in 2009</figcaption></figure> <ul><li>The <a href="/wiki/Moffat_Tunnel" title="Moffat Tunnel">Moffat Tunnel</a>, opened in 1928, passes under the <a href="/wiki/Continental_Divide_of_the_Americas" title="Continental Divide of the Americas">Continental Divide of the Americas</a> in <a href="/wiki/Colorado" title="Colorado">Colorado</a>. The tunnel is 10.0 km (6.2 mi) long and at an elevation of 2,816 m (9,239 ft) is the highest active railroad tunnel in the U.S. (The inactive <a href="/wiki/Tennessee_Pass_Line" class="mw-redirect" title="Tennessee Pass Line">Tennessee Pass Line</a> and the historic <a href="/wiki/Alpine_Tunnel" title="Alpine Tunnel">Alpine Tunnel</a> are higher.)</li> <li><a href="/wiki/Williamson%27s_tunnels" class="mw-redirect" title="Williamson's tunnels">Williamson's tunnels</a> in <a href="/wiki/Liverpool" title="Liverpool">Liverpool</a>, from 1804 and completed around 1840 by a wealthy eccentric, are probably the largest underground <a href="/wiki/Folly" title="Folly">folly</a> in the world. The tunnels were built with no functional purpose.</li> <li>The <a href="/wiki/Chicago_Tunnel_Company" title="Chicago Tunnel Company">Chicago freight tunnel network</a> is the largest urban street tunnel network, comprising 97 km (60 mi) of tunnels beneath the majority of downtown <a href="/wiki/Chicago" title="Chicago">Chicago</a> streets. It operated between 1906 and 1956 as a freight network, connecting building basements and railway stations. Following a <a href="/wiki/Chicago_flood" title="Chicago flood">1992 flood</a> the network was sealed, although some parts still carry utility and communications infrastructure.</li> <li>The <a href="/wiki/Pennsylvania_Turnpike" title="Pennsylvania Turnpike">Pennsylvania Turnpike</a> opened in 1940 with seven tunnels, most of which were bored as part of the stillborn <a href="/wiki/South_Pennsylvania_Railroad" title="South Pennsylvania Railroad">South Pennsylvania Railroad</a> and giving the highway the nickname "Tunnel Highway". Four of the tunnels (<a href="/wiki/Allegheny_Mountain_Tunnel" title="Allegheny Mountain Tunnel">Allegheny Mountain</a>, <a href="/wiki/Tuscarora_Mountain_Tunnel" title="Tuscarora Mountain Tunnel">Tuscarora Mountain</a>, <a href="/wiki/Kittatinny_Mountain_Tunnel" title="Kittatinny Mountain Tunnel">Kittatinny Mountain</a>, and <a href="/wiki/Blue_Mountain_Tunnel" title="Blue Mountain Tunnel">Blue Mountain</a>) remain in active use, while the other three (<a href="/wiki/Laurel_Hill_Tunnel" title="Laurel Hill Tunnel">Laurel Hill</a>, <a href="/wiki/Rays_Hill_Tunnel" title="Rays Hill Tunnel">Rays Hill</a>, and <a href="/wiki/Sideling_Hill_Tunnel" title="Sideling Hill Tunnel">Sideling Hill</a>) were bypassed in the 1960s; the latter two tunnels are on a bypassed section of the Turnpike now commonly known as the <a href="/wiki/Abandoned_Pennsylvania_Turnpike" title="Abandoned Pennsylvania Turnpike">Abandoned Pennsylvania Turnpike</a>.</li> <li>The <a href="/wiki/Essingeleden" title="Essingeleden">Fredhälls road tunnel</a> was opened in 1966, in <a href="/wiki/Stockholm,_Sweden" class="mw-redirect" title="Stockholm, Sweden">Stockholm, Sweden</a>, and the <a href="/wiki/Elbe_Tunnel_(1975)" title="Elbe Tunnel (1975)">New Elbe road tunnel</a> opened in 1975 in <a href="/wiki/Hamburg,_Germany" class="mw-redirect" title="Hamburg, Germany">Hamburg, Germany</a>. Both tunnels handle around 150,000 vehicles a day, making them two of the most trafficked tunnels in the world.</li> <li>The <a href="/wiki/Honningsv%C3%A5g_Tunnel" title="Honningsvåg Tunnel">Honningsvåg Tunnel</a> (4.443 km (2.76 mi) long) opened in 1999 on <a href="/wiki/European_route_E69" title="European route E69">European route E69</a> in Norway as the world's northernmost road tunnel, except for mines (which exist on <a href="/wiki/Svalbard" title="Svalbard">Svalbard</a>).</li> <li>The Central Artery road tunnel in <a href="/wiki/Boston,_Massachusetts" class="mw-redirect" title="Boston, Massachusetts">Boston, Massachusetts</a>, is a part of the larger <a href="/wiki/Big_Dig_(Boston,_Massachusetts)" class="mw-redirect" title="Big Dig (Boston, Massachusetts)">Big Dig</a> completed around 2007, and carries approximately 200,000 vehicles/day under the city along <a href="/wiki/Interstate_93" title="Interstate 93">Interstate 93</a>, <a href="/wiki/U.S._Route_1_in_Massachusetts" title="U.S. Route 1 in Massachusetts">US Route 1</a>, and <a href="/wiki/Massachusetts_Route_3" title="Massachusetts Route 3">Massachusetts Route 3</a>, which share a <a href="/wiki/Concurrency_(road)" title="Concurrency (road)">concurrency</a> through the tunnels. The Big Dig replaced Boston's old badly deteriorated I-93 elevated highway.</li> <li>The Stormwater Management And Road Tunnel or <a href="/wiki/SMART_Tunnel" title="SMART Tunnel">SMART Tunnel</a>, is a combined storm drainage and road structure opened in 2007 in <a href="/wiki/Kuala_Lumpur" title="Kuala Lumpur">Kuala Lumpur</a>, Malaysia. The 9.7 km (6.0 mi) tunnel is the longest stormwater <a href="/wiki/Drainage_tunnel" title="Drainage tunnel">drainage tunnel</a> in South East Asia and second longest in Asia. The facility can be operated as a simultaneous traffic and stormwater passage, or dedicated exclusively to stormwater when necessary.</li> <li>The <a href="/wiki/Eiksund_Tunnel" title="Eiksund Tunnel">Eiksund Tunnel</a><sup id="cite_ref-79" class="reference"><a href="#cite_note-79"><span class="cite-bracket">[</span>79<span class="cite-bracket">]</span></a></sup> on national road Rv 653 in Norway is the world's deepest subsea road tunnel, measuring 7.776 km (4.832 mi) long, with deepest point at −287 m (−942 ft) below the sea level, opened in February 2008.</li> <li><a href="/wiki/Gerrards_Cross_Tunnel" title="Gerrards Cross Tunnel">Gerrards Cross railway tunnel</a>, in England, opened in 2010, is notable in that it converted an existing railway cutting into a tunnel to create ground to build a supermarket over the tunnel. The railway in the cutting was first opened around 1906, stretching over 104 years to complete a railway tunnel. The tunnel was built using the cover method with craned in prefabricated forms in order to keep the busy railway operating. A branch of the <a href="/wiki/Tesco" title="Tesco">Tesco</a> supermarket chain occupies the newly created ground above the railway tunnel, with an adjacent existing railway station at the end of the tunnel. During construction, a portion of the tunnel collapsed when soil cover was added. The prefabricated forms were covered with a layer of reinforced concrete after the collapse.<sup id="cite_ref-80" class="reference"><a href="#cite_note-80"><span class="cite-bracket">[</span>80<span class="cite-bracket">]</span></a></sup></li> <li>The <a href="/wiki/Fenghuoshan_tunnel" class="mw-redirect" title="Fenghuoshan tunnel">Fenghuoshan tunnel</a>, completed in 2005 on the <a href="/wiki/Qinghai-Tibet_railway" class="mw-redirect" title="Qinghai-Tibet railway">Qinghai-Tibet railway</a> is the world's highest railway tunnel, about 4.905 km (3.05 mi) above sea level and 1,338 m (0.831 mi) long.</li> <li>The <a href="/wiki/La_L%C3%ADnea_(Road_Pass)" class="mw-redirect" title="La Línea (Road Pass)">La Linea</a> Tunnel in <a href="/wiki/Colombia" title="Colombia">Colombia</a>, 2016, is the longest, 8.58 km (5.33 mi), mountain tunnel in South America. It crosses beneath a mountain at 2,500 m (8,202.1 ft) above sea level with six traffic lanes, and it has a parallel emergency tunnel. The tunnel is subject to serious <a href="/wiki/Groundwater" title="Groundwater">groundwater</a> pressure. The tunnel will link <a href="/wiki/Bogot%C3%A1" title="Bogotá">Bogotá</a> and its urban area with the coffee-growing region, and with the main port on the Colombian Pacific coast.</li> <li>The <a href="/wiki/Tunnel_and_Reservoir_Plan" title="Tunnel and Reservoir Plan">Chicago Deep Tunnel Project</a> is a network of 175 km (109 mi) of <a href="/wiki/Drainage_tunnel" title="Drainage tunnel">drainage tunnels</a> designed to reduce flooding in the <a href="/wiki/Chicago_metropolitan_area" title="Chicago metropolitan area">Chicago area</a>. Started in the mid-1970s, the project is due to be completed in 2029.</li> <li><a href="/wiki/New_York_City_Water_Tunnel_No._3" title="New York City Water Tunnel No. 3">New York City Water Tunnel No. 3</a>, started in 1970, has an expected completion beyond 2026,<sup id="cite_ref-81" class="reference"><a href="#cite_note-81"><span class="cite-bracket">[</span>81<span class="cite-bracket">]</span></a></sup> and will measure more than 97 km long (60 mi).<sup id="cite_ref-82" class="reference"><a href="#cite_note-82"><span class="cite-bracket">[</span>82<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Mining">Mining</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=28" title="Edit section: Mining"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Mining" title="Mining">Mining</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:New_Pinghsi_Coal_Tunnel.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a6/New_Pinghsi_Coal_Tunnel.JPG/220px-New_Pinghsi_Coal_Tunnel.JPG" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a6/New_Pinghsi_Coal_Tunnel.JPG/330px-New_Pinghsi_Coal_Tunnel.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a6/New_Pinghsi_Coal_Tunnel.JPG/440px-New_Pinghsi_Coal_Tunnel.JPG 2x" data-file-width="2816" data-file-height="2112" /></a><figcaption>Tunnel formerly used for <a href="/wiki/Taiwan_Coal_Mine_Museum" title="Taiwan Coal Mine Museum">coal mining</a> in <a href="/wiki/New_Taipei" class="mw-redirect" title="New Taipei">New Taipei</a>, <a href="/wiki/Taiwan" title="Taiwan">Taiwan</a></figcaption></figure> <p>The use of tunnels for mining is called <a href="/wiki/Drift_mining" title="Drift mining">drift mining</a>. Drift mining can help find coal, goal, iron, and other minerals, just like normal mining. </p><p>Sub-surface mining consists of digging tunnels or shafts into the earth to reach buried ore deposits. </p> <div class="mw-heading mw-heading2"><h2 id="Military_use">Military use</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=29" title="Edit section: Military use"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Sapper" title="Sapper">Sapper</a></div> <p>Some tunnels are not for transport at all but rather, are fortifications, for example <a href="/wiki/Mittelwerk" title="Mittelwerk">Mittelwerk</a> and <a href="/wiki/Cheyenne_Mountain_Complex" title="Cheyenne Mountain Complex">Cheyenne Mountain Complex</a>. Excavation techniques, as well as the construction of underground bunkers and other habitable areas, are often associated with <a href="/wiki/Tunnel_warfare" title="Tunnel warfare">military use during armed conflict</a>, or civilian responses to threat of attack. Another use for tunnels was for the storage of chemical weapons<sup id="cite_ref-83" class="reference"><a href="#cite_note-83"><span class="cite-bracket">[</span>83<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-84" class="reference"><a href="#cite_note-84"><span class="cite-bracket">[</span>84<span class="cite-bracket">]</span></a></sup> <a rel="nofollow" class="external autonumber" href="http://www.mustardgas.org/">[1]</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Secret_tunnels">Secret tunnels</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=30" title="Edit section: Secret tunnels"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main articles: <a href="/wiki/Secret_passage" title="Secret passage">Secret passage</a> and <a href="/wiki/Smuggling_tunnel" title="Smuggling tunnel">Smuggling tunnel</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Underground_Railroad_Tunnel_Door.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/80/Underground_Railroad_Tunnel_Door.jpg/170px-Underground_Railroad_Tunnel_Door.jpg" decoding="async" width="170" height="262" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/80/Underground_Railroad_Tunnel_Door.jpg/255px-Underground_Railroad_Tunnel_Door.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/80/Underground_Railroad_Tunnel_Door.jpg/340px-Underground_Railroad_Tunnel_Door.jpg 2x" data-file-width="624" data-file-height="960" /></a><figcaption>Door to a compartment where runaway slaves would sleep, on the <a href="/wiki/Underground_Railroad" title="Underground Railroad">Underground Railroad</a></figcaption></figure> <p><a href="/wiki/Secret_passage" title="Secret passage">Secret tunnels</a> have given entrance to or escape from an area, such as the <a href="/wiki/Cu_Chi_Tunnels" class="mw-redirect" title="Cu Chi Tunnels">Cu Chi Tunnels</a> or the <a href="/wiki/Gaza_Strip_smuggling_tunnels" title="Gaza Strip smuggling tunnels">smuggling tunnels in the Gaza Strip</a> which connect it to <a href="/wiki/Egypt" title="Egypt">Egypt</a>. Although the <a href="/wiki/Underground_Railroad" title="Underground Railroad">Underground Railroad</a> network used to transport escaped slaves was "underground" mostly in the sense of secrecy, hidden tunnels were occasionally used. Secret tunnels were also used during the <a href="/wiki/Cold_War" title="Cold War">Cold War</a>, under the <a href="/wiki/Berlin_Wall" title="Berlin Wall">Berlin Wall</a> and elsewhere, to smuggle refugees, and for <a href="/wiki/Espionage" title="Espionage">espionage</a>. </p><p><a href="/wiki/Smuggler" class="mw-redirect" title="Smuggler">Smugglers</a> use secret tunnels to transport or store <a href="/wiki/Contraband" title="Contraband">contraband</a>, such as <a href="/wiki/Illegal_drugs" class="mw-redirect" title="Illegal drugs">illegal drugs</a> and <a href="/wiki/Weapon" title="Weapon">weapons</a>. Elaborately engineered 300-metre (1,000 ft) tunnels built to smuggle drugs across the Mexico-US border were estimated to require up to 9 months to complete, and an expenditure of up to $1 million.<sup id="cite_ref-Audi_85-0" class="reference"><a href="#cite_note-Audi-85"><span class="cite-bracket">[</span>85<span class="cite-bracket">]</span></a></sup> Some of these tunnels were equipped with lighting, ventilation, telephones, drainage pumps, hydraulic elevators, and in at least one instance, an electrified rail transport system.<sup id="cite_ref-Audi_85-1" class="reference"><a href="#cite_note-Audi-85"><span class="cite-bracket">[</span>85<span class="cite-bracket">]</span></a></sup> Secret tunnels have also been used by thieves to break into bank vaults and retail stores after hours.<sup id="cite_ref-Colchester_86-0" class="reference"><a href="#cite_note-Colchester-86"><span class="cite-bracket">[</span>86<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Evans_87-0" class="reference"><a href="#cite_note-Evans-87"><span class="cite-bracket">[</span>87<span class="cite-bracket">]</span></a></sup> Several tunnels have been discovered by the <a href="/wiki/Border_Security_Forces" class="mw-redirect" title="Border Security Forces">Border Security Forces</a> across the <a href="/wiki/Line_of_Control" title="Line of Control">Line of Control</a> along the <a href="/wiki/India-Pakistan_border" class="mw-redirect" title="India-Pakistan border">India-Pakistan border</a>, mainly to allow terrorists access to the Indian territory of <a href="/wiki/Jammu_and_Kashmir_(union_territory)" title="Jammu and Kashmir (union territory)">Jammu and Kashmir</a>.<sup id="cite_ref-arniatunnel_88-0" class="reference"><a href="#cite_note-arniatunnel-88"><span class="cite-bracket">[</span>88<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-sambhatunnel_89-0" class="reference"><a href="#cite_note-sambhatunnel-89"><span class="cite-bracket">[</span>89<span class="cite-bracket">]</span></a></sup> </p><p>The actual usage of <a href="/wiki/Erdstall" title="Erdstall">erdstall</a> tunnels is unknown but theories connect it to a rebirth ritual. </p> <div class="mw-heading mw-heading2"><h2 id="Natural_tunnels">Natural tunnels</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=31" title="Edit section: Natural tunnels"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Yongmun-gul_at_Daedunsan.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/16/Yongmun-gul_at_Daedunsan.jpg/170px-Yongmun-gul_at_Daedunsan.jpg" decoding="async" width="170" height="254" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/16/Yongmun-gul_at_Daedunsan.jpg/255px-Yongmun-gul_at_Daedunsan.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/16/Yongmun-gul_at_Daedunsan.jpg/340px-Yongmun-gul_at_Daedunsan.jpg 2x" data-file-width="2600" data-file-height="3888" /></a><figcaption>View through a natural tunnel in South Korea</figcaption></figure> <ul><li><a href="/wiki/Lava_tube" title="Lava tube">Lava tubes</a> are emptied lava conduits, formed during volcanic eruptions by flowing and cooling lava.</li> <li><a href="/wiki/Natural_Tunnel_State_Park" title="Natural Tunnel State Park">Natural Tunnel State Park</a> (Virginia, US) features an 260-metre (850 ft) natural tunnel, really a limestone <a href="/wiki/Cave" title="Cave">cave</a>, that has been used as a railroad tunnel since 1890.</li> <li><a href="/wiki/Punarjani_Guha" title="Punarjani Guha">Punarjani Guha</a> in <a href="/wiki/Kerala,_India" class="mw-redirect" title="Kerala, India">Kerala, India</a>. Hindus believe that crawling through the tunnel (which they believe was created by a Hindu god) from one end to the other will wash away all of one's sins and thus allow one to attain rebirth. Only men are permitted to crawl through the tunnel.</li> <li><a href="/wiki/Torghatten" title="Torghatten">Torghatten</a>, a Norwegian island with a hat-shaped silhouette, has a natural tunnel in the middle of the hat, letting light come through. The 160-metre (520 ft) long, 35-metre (115 ft) high, and 20-metre (66 ft) wide tunnel is said to be the hole made by an arrow of the angry <a href="/wiki/Troll" title="Troll">troll</a> Hestmannen, the hill being the hat of the troll-king of <a href="/wiki/S%C3%B8mna_Municipality" title="Sømna Municipality">Sømna</a> trying to save the beautiful <a href="/wiki/Lekam%C3%B8ya" title="Lekamøya">Lekamøya</a>. The tunnel is thought actually to be the work of ice. The sun shines through the tunnel during two few minutes long periods every year.<sup id="cite_ref-90" class="reference"><a href="#cite_note-90"><span class="cite-bracket">[</span>90<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Major_accidents">Major accidents</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=32" title="Edit section: Major accidents"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Clayton_Tunnel_rail_crash" title="Clayton Tunnel rail crash">Clayton Tunnel rail crash</a> (1861) – confusion about block signals leading to collision, 23 killed.</li> <li><a href="/wiki/Welwyn_Tunnel_rail_crash" title="Welwyn Tunnel rail crash">Welwyn Tunnel rail crash</a> (1866) – train failed in tunnel, guard did not protect train.</li> <li><a href="/wiki/Paris_M%C3%A9tro_train_fire" title="Paris Métro train fire">Paris Métro train fire</a> (1904) – train fire in Couronnes underground station, 84 killed by smoke and gases.</li> <li><a href="/wiki/Church_Hill_Tunnel" title="Church Hill Tunnel">Church Hill Tunnel collapse</a> (1925) – tunnel collapse on a work train during renovation, killing four men and trapping a steam locomotive and ten flat cars.</li> <li><a href="/wiki/Balvano_train_disaster" title="Balvano train disaster">Balvano train disaster</a> (1944) – asphyxiation of about 500 "unofficial" passengers on freight train.</li> <li><a href="/wiki/Caldecott_Tunnel_fire" title="Caldecott Tunnel fire">Caldecott Tunnel fire</a> (1982) – major motor vehicle tunnel crash and fire.</li> <li><a href="/wiki/1996_Channel_Tunnel_fire" title="1996 Channel Tunnel fire">Channel Tunnel fire</a> (1996) – Train carrying <a href="/wiki/Large_goods_vehicle" title="Large goods vehicle">Heavy Good Vehicles (HGV)</a> caught on fire.</li> <li><a href="/wiki/Death_of_Diana,_Princess_of_Wales" title="Death of Diana, Princess of Wales">Princess Diana's death</a> (1997) – Car crash in <a href="/wiki/Pont_de_l%27Alma" title="Pont de l'Alma">Pont de l'Alma</a> tunnel, <a href="/wiki/Paris" title="Paris">Paris</a>, which killed <a href="/wiki/Princess_Diana" class="mw-redirect" title="Princess Diana">Princess Diana</a>.</li> <li><a href="/wiki/Mont_Blanc_tunnel_fire" class="mw-redirect" title="Mont Blanc tunnel fire">Mont Blanc Tunnel fire</a> (1999) – Transport truck caught on fire and combusted inside tunnel.</li> <li><a href="/wiki/Big_Dig_ceiling_collapse" title="Big Dig ceiling collapse">Big Dig Ceiling collapse</a> (2006) – Concrete ceiling panel falls in <a href="/wiki/Fort_Point_Tunnel" class="mw-redirect" title="Fort Point Tunnel">Fort Point</a> tunnel, <a href="/wiki/Boston" title="Boston">Boston</a>, which causes the <a href="/wiki/Big_Dig" title="Big Dig">Big Dig project</a> to be closed for a year.</li></ul> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=33" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1184024115">.mw-parser-output .div-col{margin-top:0.3em;column-width:30em}.mw-parser-output .div-col-small{font-size:90%}.mw-parser-output .div-col-rules{column-rule:1px solid #aaa}.mw-parser-output .div-col dl,.mw-parser-output .div-col ol,.mw-parser-output .div-col ul{margin-top:0}.mw-parser-output .div-col li,.mw-parser-output .div-col dd{page-break-inside:avoid;break-inside:avoid-column}</style><div class="div-col"> <ul><li><a href="/wiki/Euphrates_Tunnel" title="Euphrates Tunnel">Euphrates Tunnel</a></li> <li><a href="/wiki/Cattle_creep" title="Cattle creep">Cattle creep</a></li> <li><a href="/wiki/Counter-beam_lighting" title="Counter-beam lighting">Counter-beam lighting</a></li> <li><a href="/wiki/Culvert" title="Culvert">Culvert</a></li> <li><a href="/wiki/Hobby_tunneling" title="Hobby tunneling">Hobby tunneling</a></li> <li><a href="/wiki/Megaproject" title="Megaproject">Megaproject</a></li> <li><a href="/wiki/Rapid_transit" title="Rapid transit">Rapid transit</a></li> <li><a href="/wiki/Sequential_Excavation_Method" class="mw-redirect" title="Sequential Excavation Method">Sequential Excavation Method</a></li> <li><a href="/wiki/Structure_gauge" title="Structure gauge">Structure gauge</a> – measure of maximum physical clearance in a tunnel</li> <li><a href="/wiki/Tree_tunnel" title="Tree tunnel">Tree tunnel</a> – tunnel-like effect from tree canopies above a road</li> <li><a href="/wiki/Tunnel_tree" title="Tunnel tree">Tunnel tree</a> – tunnel bored through the trunk of a tree</li> <li><a href="/wiki/Tunnels_in_popular_culture" title="Tunnels in popular culture">Tunnels in popular culture</a></li> <li><a href="/wiki/Underground_living" title="Underground living">Underground living</a></li></ul> </div> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=34" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-columns references-column-width" style="column-width: 30em;"> <ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFZhouSuChenAn2022" class="citation journal cs1">Zhou, Man; Su, Xiaolong; Chen, Yaying; An, Lin (2 October 2022). <a rel="nofollow" class="external text" href="https://www.tandfonline.com/doi/full/10.1080/10168664.2021.1904487">"New Technologies and Challenges in the Construction of the Immersed Tube Tunnel of the Hong Kong-Zhuhai-Macao Link"</a>. <i>Structural Engineering International</i>. <b>32</b> (4): 455–464. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1080%2F10168664.2021.1904487">10.1080/10168664.2021.1904487</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1016-8664">1016-8664</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Structural+Engineering+International&rft.atitle=New+Technologies+and+Challenges+in+the+Construction+of+the+Immersed+Tube+Tunnel+of+the+Hong+Kong-Zhuhai-Macao+Link&rft.volume=32&rft.issue=4&rft.pages=455-464&rft.date=2022-10-02&rft_id=info%3Adoi%2F10.1080%2F10168664.2021.1904487&rft.issn=1016-8664&rft.aulast=Zhou&rft.aufirst=Man&rft.au=Su%2C+Xiaolong&rft.au=Chen%2C+Yaying&rft.au=An%2C+Lin&rft_id=https%3A%2F%2Fwww.tandfonline.com%2Fdoi%2Ffull%2F10.1080%2F10168664.2021.1904487&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFTakahashi2009" class="citation book cs1">Takahashi, Yutaka (2009). <i>Water Storage, Transport, and Distribution</i>. <a href="/w/index.php?title=EOLSS_Publications&action=edit&redlink=1" class="new" title="EOLSS Publications (page does not exist)">EOLSS Publications</a>. pp. 318–319. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/9781848261761" title="Special:BookSources/9781848261761"><bdi>9781848261761</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Water+Storage%2C+Transport%2C+and+Distribution&rft.pages=318-319&rft.pub=EOLSS+Publications&rft.date=2009&rft.isbn=9781848261761&rft.aulast=Takahashi&rft.aufirst=Yutaka&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text">Salazar, Waneta. <i>Tunnels in Civil Engineering</i>. Delhi, India : White Word Publications, 2012.</span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSorrensen2014" class="citation journal cs1">Sorrensen, Cynthia (1 July 2014). <a rel="nofollow" class="external text" href="https://www.tandfonline.com/doi/full/10.1111/j.1931-0846.2014.12029.x">"Making the Subterranean Visible: Security, Tunnels, and the United States–Mexico Border"</a>. <i>Geographical Review</i>. <b>104</b> (3): 328–345. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1111%2Fj.1931-0846.2014.12029.x">10.1111/j.1931-0846.2014.12029.x</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0016-7428">0016-7428</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Geographical+Review&rft.atitle=Making+the+Subterranean+Visible%3A+Security%2C+Tunnels%2C+and+the+United+States%E2%80%93Mexico+Border&rft.volume=104&rft.issue=3&rft.pages=328-345&rft.date=2014-07-01&rft_id=info%3Adoi%2F10.1111%2Fj.1931-0846.2014.12029.x&rft.issn=0016-7428&rft.aulast=Sorrensen&rft.aufirst=Cynthia&rft_id=https%3A%2F%2Fwww.tandfonline.com%2Fdoi%2Ffull%2F10.1111%2Fj.1931-0846.2014.12029.x&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">Brodziewska, J. (2005). Wildlife tunnels and fauna bridges in Poland: past, present and future, 1997-2013. <i>UC Davis: Road Ecology Center</i>. Retrieved from https://escholarship.org/uc/item/4wd0j27j</span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://www.standardsforhighways.co.uk/tses/attachments/987a669b-13a1-40b9-94da-1ea4e4604fdd"><i>Highway Structures & Bridges Design CD 352, Design of road tunnels (formerly BD 78/99)</i></a>. The Department for Transport. 2020.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Highway+Structures+%26+Bridges+Design+CD+352%2C+Design+of+road+tunnels+%28formerly+BD+78%2F99%29&rft.pub=The+Department+for+Transport&rft.date=2020&rft_id=https%3A%2F%2Fwww.standardsforhighways.co.uk%2Ftses%2Fattachments%2F987a669b-13a1-40b9-94da-1ea4e4604fdd&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><i>NFPA Standard for Safeguarding Construction, Alteration, and Demolition Operations</i>. National Fire Protection Association.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=NFPA+Standard+for+Safeguarding+Construction%2C+Alteration%2C+and+Demolition+Operations&rft.pub=National+Fire+Protection+Association&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation cs2"><a rel="nofollow" class="external text" href="https://oed.com/dictionary/tunnel_n">"tunnel, n."</a>, <i>Oxford English Dictionary</i> (3 ed.), Oxford University Press, 2 March 2023, <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Foed%2F1137765320">10.1093/oed/1137765320</a><span class="reference-accessdate">, retrieved <span class="nowrap">1 September</span> 2024</span></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Oxford+English+Dictionary&rft.atitle=tunnel%2C+n.&rft.date=2023-03-02&rft_id=info%3Adoi%2F10.1093%2Foed%2F1137765320&rft_id=https%3A%2F%2Foed.com%2Fdictionary%2Ftunnel_n&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFrank,_de_Carvalho_Buchmann,_Gonçalves_de_Lima,_Caron,_Lopes_&_Fornari2011" class="citation journal cs1">Frank, de Carvalho Buchmann, Gonçalves de Lima, Caron, Lopes & Fornari (2011). <a rel="nofollow" class="external text" href="https://www.ufrgs.br/paleotocas/Frank_et_al_2011b.pdf">"KARSTIC FEATURES GENERATED FROM LARGE PALAEOVERTEBRATE TUNNELS IN SOUTHERN BRAZIL"</a> <span class="cs1-format">(PDF)</span>. <i>Espeleo-Tema</i>. <b>22</b> (1).</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Espeleo-Tema&rft.atitle=KARSTIC+FEATURES+GENERATED+FROM+LARGE+PALAEOVERTEBRATE+TUNNELS+IN+SOUTHERN+BRAZIL&rft.volume=22&rft.issue=1&rft.date=2011&rft.au=Frank%2C+de+Carvalho+Buchmann%2C+Gon%C3%A7alves+de+Lima%2C+Caron%2C+Lopes+%26+Fornari&rft_id=https%3A%2F%2Fwww.ufrgs.br%2Fpaleotocas%2FFrank_et_al_2011b.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_journal" title="Template:Cite journal">cite journal</a>}}</code>: CS1 maint: multiple names: authors list (<a href="/wiki/Category:CS1_maint:_multiple_names:_authors_list" title="Category:CS1 maint: multiple names: authors list">link</a>)</span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFgzichnalis2022" class="citation web cs1">gzichnalis (15 January 2022). <a rel="nofollow" class="external text" href="https://wtc2023.gr/eupalinos-tunnel-first-tunnel-to-be-excavated-simultaneously-from-both-ends-in-the-6th-centurty-b-c/">"Eupalinos Tunnel – First Tunnel to be excavated simultaneously from both ends in the 6th centurty B.C."</a> <i>WTC2023</i><span class="reference-accessdate">. Retrieved <span class="nowrap">26 September</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=WTC2023&rft.atitle=Eupalinos+Tunnel+%E2%80%93+First+Tunnel+to+be+excavated+simultaneously+from+both+ends+in+the+6th+centurty+B.C.&rft.date=2022-01-15&rft.au=gzichnalis&rft_id=https%3A%2F%2Fwtc2023.gr%2Feupalinos-tunnel-first-tunnel-to-be-excavated-simultaneously-from-both-ends-in-the-6th-centurty-b-c%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external free" href="https://www.safeworkaustralia.gov.au/system/files/documents/1702/guide-tunnelling.pdf">https://www.safeworkaustralia.gov.au/system/files/documents/1702/guide-tunnelling.pdf</a></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSutcliffe2004" class="citation book cs1">Sutcliffe, Harry (2004). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=59V5BgAAQBAJ&pg=PA210">"Tunnel Boring Machines"</a>. In Bickel, John O.; Kuesel, Thomas R.; King, Elwyn H. (eds.). <i>Tunnel Engineering Handbook</i> (2nd ed.). Kluwer Academic Publishers. p. 210. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-4613-8053-5" title="Special:BookSources/978-1-4613-8053-5"><bdi>978-1-4613-8053-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Tunnel+Boring+Machines&rft.btitle=Tunnel+Engineering+Handbook&rft.pages=210&rft.edition=2nd&rft.pub=Kluwer+Academic+Publishers&rft.date=2004&rft.isbn=978-1-4613-8053-5&rft.aulast=Sutcliffe&rft.aufirst=Harry&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3D59V5BgAAQBAJ%26pg%3DPA210&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text">Powers, P.J. (2007). Construction dewatering and groundwater control. Hoboken, NJ: John Wiley & Sons Inc.</span> </li> <li id="cite_note-Engineers._1978-14"><span class="mw-cite-backlink">^ <a href="#cite_ref-Engineers._1978_14-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Engineers._1978_14-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">United States Army Corps of Engineers. (1978). Tunnels and shafts in rock. Washington, DC: Department of the Army.</span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.worldhighways.com/wh10/feature/tunnels-environmentally-attractive-option">"Tunnels - an environmentally attractive option?"</a>. <i>World Highways</i><span class="reference-accessdate">. Retrieved <span class="nowrap">8 October</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=World+Highways&rft.atitle=Tunnels+-+an+environmentally+attractive+option%3F&rft_id=https%3A%2F%2Fwww.worldhighways.com%2Fwh10%2Ffeature%2Ftunnels-environmentally-attractive-option&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.fhwa.dot.gov/ipd/project_profiles/ma_boston_central_artery.aspx">"FHWA - Center for Innovative Finance Support - Project Profiles"</a>. <i>www.fhwa.dot.gov</i><span class="reference-accessdate">. Retrieved <span class="nowrap">8 November</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.fhwa.dot.gov&rft.atitle=FHWA+-+Center+for+Innovative+Finance+Support+-+Project+Profiles&rft_id=https%3A%2F%2Fwww.fhwa.dot.gov%2Fipd%2Fproject_profiles%2Fma_boston_central_artery.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.bbc.com/news/articles/c7283vplp56o">"Queensway Tunnel which links Liverpool to Birkenhead marks 90th anniversary"</a>. <i>www.bbc.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">8 October</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.bbc.com&rft.atitle=Queensway+Tunnel+which+links+Liverpool+to+Birkenhead+marks+90th+anniversary&rft_id=https%3A%2F%2Fwww.bbc.com%2Fnews%2Farticles%2Fc7283vplp56o&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20111217080357/http://www.cord.edu/faculty/bfoss/ADVC20.htm">"Capital Projects Funds"</a>. Cord.edu. Archived from <a rel="nofollow" class="external text" href="http://www.cord.edu/faculty/bfoss/ADVC20.htm">the original</a> on 17 December 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Capital+Projects+Funds&rft.pub=Cord.edu&rft_id=http%3A%2F%2Fwww.cord.edu%2Ffaculty%2Fbfoss%2FADVC20.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFChan2005" class="citation news cs1">Chan, Sewell (3 August 2005). <a rel="nofollow" class="external text" href="https://www.nytimes.com/2005/08/03/nyregion/03rail.html?_r=0">"$100 Million for a Tunnel. What Tunnel?"</a>. <i>The New York Times</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=%24100+Million+for+a+Tunnel.+What+Tunnel%3F&rft.date=2005-08-03&rft.aulast=Chan&rft.aufirst=Sewell&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2005%2F08%2F03%2Fnyregion%2F03rail.html%3F_r%3D0&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130523092826/http://www.cfr.org/infrastructure/encouraging-us-infrastructure-investment/p27771">"Encouraging U.S. Infrastructure Investment – Council on Foreign Relations"</a>. Cfr.org. Archived from <a rel="nofollow" class="external text" href="http://www.cfr.org/infrastructure/encouraging-us-infrastructure-investment/p27771">the original</a> on 23 May 2013<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Encouraging+U.S.+Infrastructure+Investment+%E2%80%93+Council+on+Foreign+Relations&rft.pub=Cfr.org&rft_id=http%3A%2F%2Fwww.cfr.org%2Finfrastructure%2Fencouraging-us-infrastructure-investment%2Fp27771&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-FOOTNOTEEllis2015118-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEEllis2015118_21-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFEllis2015">Ellis 2015</a>, p. 118.</span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKonyukhov2022" class="citation journal cs1">Konyukhov, D. S. (12 April 2022). <a rel="nofollow" class="external text" href="https://mst.misis.ru/jour/article/view/330">"Analysis of mechanized tunneling parameters to determine the overcutting characteristics"</a>. <i>Gornye Nauki I Tekhnologii = Mining Science and Technology (Russia)</i>. <b>7</b> (1): 49–56. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.17073%2F2500-0632-2022-1-49-56">10.17073/2500-0632-2022-1-49-56</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/2500-0632">2500-0632</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:248136002">248136002</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Gornye+Nauki+I+Tekhnologii+%3D+Mining+Science+and+Technology+%28Russia%29&rft.atitle=Analysis+of+mechanized+tunneling+parameters+to+determine+the+overcutting+characteristics&rft.volume=7&rft.issue=1&rft.pages=49-56&rft.date=2022-04-12&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A248136002%23id-name%3DS2CID&rft.issn=2500-0632&rft_id=info%3Adoi%2F10.17073%2F2500-0632-2022-1-49-56&rft.aulast=Konyukhov&rft.aufirst=D.+S.&rft_id=https%3A%2F%2Fmst.misis.ru%2Fjour%2Farticle%2Fview%2F330&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20100823081917/http://tunnellersmemorial.com/Tunnelling.htm">"Tunnelling"</a>. <i>The Tunneller's Memorial, Givenchy</i>. 2009. Archived from <a rel="nofollow" class="external text" href="http://tunnellersmemorial.com/Tunnelling.htm">the original</a> on 23 August 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">20 June</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=The+Tunneller%27s+Memorial%2C+Givenchy&rft.atitle=Tunnelling&rft.date=2009&rft_id=http%3A%2F%2Ftunnellersmemorial.com%2FTunnelling.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120316162001/http://www.tunnelsonline.info/story.asp?sectioncode=1&storycode=61846">"Tunnels & Tunnelling International"</a>. <i>Tunnelsonline.info</i>. Archived from <a rel="nofollow" class="external text" href="http://www.tunnelsonline.info/story.asp?sectioncode=1&storycode=61846">the original</a> on 16 March 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Tunnelsonline.info&rft.atitle=Tunnels+%26+Tunnelling+International&rft_id=http%3A%2F%2Fwww.tunnelsonline.info%2Fstory.asp%3Fsectioncode%3D1%26storycode%3D61846&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20090925160241/http://www.hslzuid.nl/hsl/uk/bouw/ment/Bored_Tunnel_Groene_Hart/index.jsp">"The Groene Hart Tunnel"</a>. <i>Hslzuid.nl</i>. Archived from <a rel="nofollow" class="external text" href="http://www.hslzuid.nl/hsl/uk/bouw/ment/Bored_Tunnel_Groene_Hart/index.jsp">the original</a> on 25 September 2009<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Hslzuid.nl&rft.atitle=The+Groene+Hart+Tunnel&rft_id=http%3A%2F%2Fwww.hslzuid.nl%2Fhsl%2Fuk%2Fbouw%2Fment%2FBored_Tunnel_Groene_Hart%2Findex.jsp&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-NYT_Dec_2012-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-NYT_Dec_2012_26-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJohnson2012" class="citation news cs1">Johnson, Kirk (5 December 2012). <span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://www.nytimes.com/2012/12/05/us/projects-to-transform-seattle-all-along-the-waterfront.html">"Engineering Projects Will Transform Seattle, All Along the Waterfront"</a></span>. <i><a href="/wiki/The_New_York_Times" title="The New York Times">The New York Times</a></i><span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=Engineering+Projects+Will+Transform+Seattle%2C+All+Along+the+Waterfront&rft.date=2012-12-05&rft.aulast=Johnson&rft.aufirst=Kirk&rft_id=https%3A%2F%2Fwww.nytimes.com%2F2012%2F12%2F05%2Fus%2Fprojects-to-transform-seattle-all-along-the-waterfront.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-tbm20181205-27"><span class="mw-cite-backlink">^ <a href="#cite_ref-tbm20181205_27-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-tbm20181205_27-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-tbm20181205_27-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation news cs1"><a rel="nofollow" class="external text" href="https://tunnelingonline.com/understanding-the-new-austrian-tunnel-method-natm/">"Understanding the New Austrian Tunnel Method (NATM)"</a>. <i>Tunnel Business Magazine</i>. Benjamin Media. 5 December 2018<span class="reference-accessdate">. Retrieved <span class="nowrap">27 December</span> 2018</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Tunnel+Business+Magazine&rft.atitle=Understanding+the+New+Austrian+Tunnel+Method+%28NATM%29&rft.date=2018-12-05&rft_id=https%3A%2F%2Ftunnelingonline.com%2Funderstanding-the-new-austrian-tunnel-method-natm%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-Company_Website-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-Company_Website_28-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSun" class="citation web cs1">Sun, Li. <a rel="nofollow" class="external text" href="http://web.archive.org/web/20180316053305/http://www.li-sunexoticmushrooms.com.au/">"Mushrooms and Tours | Li-Sun Exotic Mushrooms"</a>. <i>www.li-sunexoticmushrooms.com.au</i>. Archived from the original on 16 March 2018<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.li-sunexoticmushrooms.com.au&rft.atitle=Mushrooms+and+Tours+%7C+Li-Sun+Exotic+Mushrooms&rft.aulast=Sun&rft.aufirst=Li&rft_id=http%3A%2F%2Fwww.li-sunexoticmushrooms.com.au%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_web" title="Template:Cite web">cite web</a>}}</code>: CS1 maint: unfit URL (<a href="/wiki/Category:CS1_maint:_unfit_URL" title="Category:CS1 maint: unfit URL">link</a>)</span></span> </li> <li id="cite_note-Article_on_Closure-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-Article_on_Closure_29-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBiscoe2014" class="citation web cs1">Biscoe, Emma (15 May 2014). <span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://www.illawarramercury.com.au/story/2284594/mittagong-mushroom-business-will-close-down/">"Mittagong mushroom business will close down"</a></span>. <i>Illawarra Mercury</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Illawarra+Mercury&rft.atitle=Mittagong+mushroom+business+will+close+down&rft.date=2014-05-15&rft.aulast=Biscoe&rft.aufirst=Emma&rft_id=https%3A%2F%2Fwww.illawarramercury.com.au%2Fstory%2F2284594%2Fmittagong-mushroom-business-will-close-down%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-30">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.scienceandsociety.co.uk/results.asp?image=10445941">"National Railway Museum / Science & Society image # 10445941"</a>. <i>Science & Society Picture Library</i>. 1881. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160304114308/http://i34.tinypic.com/23ixthy.jpg">Archived</a> from the original on 4 March 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Science+%26+Society+Picture+Library&rft.atitle=National+Railway+Museum+%2F+Science+%26+Society+image+%23+10445941&rft.date=1881&rft_id=https%3A%2F%2Fwww.scienceandsociety.co.uk%2Fresults.asp%3Fimage%3D10445941&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.scienceandsociety.co.uk/results.asp?image=10445944">"National Railway Museum / Science & Society image # 10445944: "Building a railway bridge in Liverpool, 1881"<span class="cs1-kern-right"></span>"</a>. <i>Science & Society Picture Library</i>. 1881. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160304185533/http://i36.tinypic.com/16k1ahx.jpg">Archived</a> from the original on 4 March 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">24 January</span> 2023</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Science+%26+Society+Picture+Library&rft.atitle=National+Railway+Museum+%2F+Science+%26+Society+image+%23+10445944%3A+%22Building+a+railway+bridge+in+Liverpool%2C+1881%22&rft.date=1881&rft_id=https%3A%2F%2Fwww.scienceandsociety.co.uk%2Fresults.asp%3Fimage%3D10445944&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-32">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.railwaygazette.com/uks-biggest-tbm-rebores-farnworth-tunnel/41248.article">"UK's biggest TBM rebores Farnworth Tunnel"</a>. <i>Railway Gazette International</i>. 12 August 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Railway+Gazette+International&rft.atitle=UK%27s+biggest+TBM+rebores+Farnworth+Tunnel&rft.date=2015-08-12&rft_id=https%3A%2F%2Fwww.railwaygazette.com%2Fuks-biggest-tbm-rebores-farnworth-tunnel%2F41248.article&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-33">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.tunnel-online.info/en/artikel/tunnel_2012-04_Report_on_Redeveloping_Railway_Tunnels_1433844.html">"Report on Redeveloping Railway Tunnels"</a>. <i>www.tunnel-online.info</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.tunnel-online.info&rft.atitle=Report+on+Redeveloping+Railway+Tunnels&rft_id=http%3A%2F%2Fwww.tunnel-online.info%2Fen%2Fartikel%2Ftunnel_2012-04_Report_on_Redeveloping_Railway_Tunnels_1433844.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-34">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20161107072916/http://mtc.ca.gov/about-mtc/what-mtc/bay-area-toll-authority/san-francisco-oakland-bay-bridge">"San Francisco-Oakland Bay Bridge"</a>. <i>Bay Area Toll Authority</i>. 4 November 2015. Archived from <a rel="nofollow" class="external text" href="http://mtc.ca.gov/about-mtc/what-mtc/bay-area-toll-authority/san-francisco-oakland-bay-bridge">the original</a> on 7 November 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Bay+Area+Toll+Authority&rft.atitle=San+Francisco-Oakland+Bay+Bridge&rft.date=2015-11-04&rft_id=http%3A%2F%2Fmtc.ca.gov%2Fabout-mtc%2Fwhat-mtc%2Fbay-area-toll-authority%2Fsan-francisco-oakland-bay-bridge&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-uc-35"><span class="mw-cite-backlink"><b><a href="#cite_ref-uc_35-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20160120170635/http://events.unicredit-cib.eu/uploads/media/Presentation_Basar_Arioglu_Yapi_Merkezi_Insaat.pdf">"Eurasia Tunnel Project"</a> <span class="cs1-format">(PDF)</span>. <a href="/wiki/Unicredit" class="mw-redirect" title="Unicredit">Unicredit</a> – Yapı Merkezi, SK EC Joint Venture. Archived from the original on 20 January 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">13 April</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Eurasia+Tunnel+Project&rft.pub=Unicredit+%E2%80%93+Yap%C4%B1+Merkezi%2C+SK+EC+Joint+Venture&rft_id=http%3A%2F%2Fevents.unicredit-cib.eu%2Fuploads%2Fmedia%2FPresentation_Basar_Arioglu_Yapi_Merkezi_Insaat.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_web" title="Template:Cite web">cite web</a>}}</code>: CS1 maint: unfit URL (<a href="/wiki/Category:CS1_maint:_unfit_URL" title="Category:CS1 maint: unfit URL">link</a>)</span></span> </li> <li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-36">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.dailysabah.com/business/2015/02/27/istanbuls-megaproject-worlds-first-threelevel-tunnel-to-be-built-under-the-bosporus">"Istanbul's mega-project: World's first three-level tunnel to be built under the Bosporus – Daily Sabah"</a>. <i><a href="/wiki/Daily_Sabah" title="Daily Sabah">Daily Sabah</a></i>. 27 February 2015. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170219015521/https://www.dailysabah.com/business/2015/02/27/istanbuls-megaproject-worlds-first-threelevel-tunnel-to-be-built-under-the-bosporus">Archived</a> from the original on 19 February 2017<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Daily+Sabah&rft.atitle=Istanbul%27s+mega-project%3A+World%27s+first+three-level+tunnel+to+be+built+under+the+Bosporus+%E2%80%93+Daily+Sabah&rft.date=2015-02-27&rft_id=https%3A%2F%2Fwww.dailysabah.com%2Fbusiness%2F2015%2F02%2F27%2Fistanbuls-megaproject-worlds-first-threelevel-tunnel-to-be-built-under-the-bosporus&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.china.org.cn/english/China/47409.htm">"Shanghai to Dig Double-deck Tunnel"</a>. <i>China Facts and Figures 2002</i>. 1 November 2002. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20060515033120/http://www.china.org.cn/english/China/47409.htm">Archived</a> from the original on 15 May 2006<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=China+Facts+and+Figures+2002&rft.atitle=Shanghai+to+Dig+Double-deck+Tunnel&rft.date=2002-11-01&rft_id=http%3A%2F%2Fwww.china.org.cn%2Fenglish%2FChina%2F47409.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-38">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKalus2016" class="citation web cs1">Kalus, Ruben (22 December 2016). <a rel="nofollow" class="external text" href="http://www.dw.com/en/maastrichts-new-highway-tunnel-a-role-model-for-europe/av-36867098">"Maastricht's new highway tunnel: a role model for Europe"</a>. <i>DW.COM</i><span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=DW.COM&rft.atitle=Maastricht%27s+new+highway+tunnel%3A+a+role+model+for+Europe&rft.date=2016-12-22&rft.aulast=Kalus&rft.aufirst=Ruben&rft_id=http%3A%2F%2Fwww.dw.com%2Fen%2Fmaastrichts-new-highway-tunnel-a-role-model-for-europe%2Fav-36867098&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-39">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20150817110627/http://imtech.com/EN/traffic-infra/Traffic-Infra-Newsroom/Divisie-Imtech-Traffic-Infra-Homepage-Newsroom-Highlights/Unique-stacked-tunnel-under-Maastricht.html">"Unique stacked tunnel under Maastricht - Division Traffic & Infra"</a>. <i>Imtech</i>. 17 August 2015. Archived from <a rel="nofollow" class="external text" href="http://imtech.com/EN/traffic-infra/Traffic-Infra-Newsroom/Divisie-Imtech-Traffic-Infra-Homepage-Newsroom-Highlights/Unique-stacked-tunnel-under-Maastricht.html">the original</a> on 17 August 2015<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Imtech&rft.atitle=Unique+stacked+tunnel+under+Maastricht+-+Division+Traffic+%26+Infra&rft.date=2015-08-17&rft_id=http%3A%2F%2Fimtech.com%2FEN%2Ftraffic-infra%2FTraffic-Infra-Newsroom%2FDivisie-Imtech-Traffic-Infra-Homepage-Newsroom-Highlights%2FUnique-stacked-tunnel-under-Maastricht.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-40"><span class="mw-cite-backlink"><b><a href="#cite_ref-40">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation news cs1"><a rel="nofollow" class="external text" href="http://fultonhistory.com/highlighter/highlight-for-xml?altUrl=http%3A%2F%2Ffultonhistory.com%2FNewspapers%252023%2FForest%2520Parkway%2520NY%2520Leader%2520Observer%2FForest%2520Parkway%2520NY%2520Leader%2520Observer%25201969-1971%2FForest%2520Parkway%2520NY%2520Leader%2520Observer%25201969-1971%2520-%25200628.pdf&highlightsFile=http%3A%2F%2Ffultonhistory.com%2Fhighlighter%2Fhits%2F816c7feba198b14dee5deb0dc12d134f#page=1">"To Break Ground For 63rd St., East River Tunnel"</a>. <i>New York Leader-Observer</i>. 20 November 1969. p. 8<span class="reference-accessdate">. Retrieved <span class="nowrap">29 July</span> 2016</span> – via <a href="/wiki/Old_Fulton_New_York_Postcards" class="mw-redirect" title="Old Fulton New York Postcards">Old Fulton New York Postcards</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=New+York+Leader-Observer&rft.atitle=To+Break+Ground+For+63rd+St.%2C+East+River+Tunnel&rft.pages=8&rft.date=1969-11-20&rft_id=http%3A%2F%2Ffultonhistory.com%2Fhighlighter%2Fhighlight-for-xml%3FaltUrl%3Dhttp%253A%252F%252Ffultonhistory.com%252FNewspapers%25252023%252FForest%252520Parkway%252520NY%252520Leader%252520Observer%252FForest%252520Parkway%252520NY%252520Leader%252520Observer%2525201969-1971%252FForest%252520Parkway%252520NY%252520Leader%252520Observer%2525201969-1971%252520-%2525200628.pdf%26highlightsFile%3Dhttp%253A%252F%252Ffultonhistory.com%252Fhighlighter%252Fhits%252F816c7feba198b14dee5deb0dc12d134f%23page%3D1&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="#cite_ref-41">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation news cs1"><span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://www.nytimes.com/1972/10/11/archives/governor-rockefeller-and-mayor-lindsay-attend-holing-through-of-63d.html">"Governor Rockefeller and Mayor Lindsay Attend 'Holing Through' of 63d St. Tunnel"</a></span>. <i>The New York Times</i>. 11 October 1972. p. 47. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0362-4331">0362-4331</a><span class="reference-accessdate">. Retrieved <span class="nowrap">3 February</span> 2018</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=Governor+Rockefeller+and+Mayor+Lindsay+Attend+%27Holing+Through%27+of+63d+St.+Tunnel&rft.pages=47&rft.date=1972-10-11&rft.issn=0362-4331&rft_id=https%3A%2F%2Fwww.nytimes.com%2F1972%2F10%2F11%2Farchives%2Fgovernor-rockefeller-and-mayor-lindsay-attend-holing-through-of-63d.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-42"><span class="mw-cite-backlink"><b><a href="#cite_ref-42">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLorch1989" class="citation news cs1">Lorch, Donatella (29 October 1989). <span class="id-lock-subscription" title="Paid subscription required"><a rel="nofollow" class="external text" href="https://www.nytimes.com/1989/10/29/nyregion/the-subway-to-nowhere-now-goes-somewhere.html">"The 'Subway to Nowhere' Now Goes Somewhere"</a></span>. <i>The New York Times</i>. p. 1.37<span class="reference-accessdate">. Retrieved <span class="nowrap">20 October</span> 2011</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+New+York+Times&rft.atitle=The+%27Subway+to+Nowhere%27+Now+Goes+Somewhere&rft.pages=1.37&rft.date=1989-10-29&rft.aulast=Lorch&rft.aufirst=Donatella&rft_id=https%3A%2F%2Fwww.nytimes.com%2F1989%2F10%2F29%2Fnyregion%2Fthe-subway-to-nowhere-now-goes-somewhere.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-43"><span class="mw-cite-backlink"><b><a href="#cite_ref-43">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://new.mta.info/project/east-side-access">"East Side Access"</a>. <i>MTA</i>. 5 October 2023<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=MTA&rft.atitle=East+Side+Access&rft.date=2023-10-05&rft_id=https%3A%2F%2Fnew.mta.info%2Fproject%2Feast-side-access&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-44"><span class="mw-cite-backlink"><b><a href="#cite_ref-44">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.waterworld.com/technologies/pipes/article/16216777/black-veatch-uses-trenchless-technology-for-water-main-rehabilitation-in-hong-kong">"Black & Veatch uses trenchless technology for water main rehabilitation in Hong Kong – WaterWorld"</a>. 5 June 2017. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20170605114200/http://www.waterworld.com/articles/2009/08/black--veatch-uses.html">Archived</a> from the original on 5 June 2017.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Black+%26+Veatch+uses+trenchless+technology+for+water+main+rehabilitation+in+Hong+Kong+%E2%80%93+WaterWorld&rft.date=2017-06-05&rft_id=https%3A%2F%2Fwww.waterworld.com%2Ftechnologies%2Fpipes%2Farticle%2F16216777%2Fblack-veatch-uses-trenchless-technology-for-water-main-rehabilitation-in-hong-kong&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-45"><span class="mw-cite-backlink"><b><a href="#cite_ref-45">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20190716063606/http://www.xinhuanet.com/2018-10/01/c_129964700.htm">"新闻分析：这条隧道藏了多少科技秘密——揭秘"万里长江公铁第一隧"-新华网"</a>. <i>www.xinhuanet.com</i>. Archived from <a rel="nofollow" class="external text" href="http://www.xinhuanet.com/2018-10/01/c_129964700.htm">the original</a> on 16 July 2019<span class="reference-accessdate">. Retrieved <span class="nowrap">7 June</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.xinhuanet.com&rft.atitle=%E6%96%B0%E9%97%BB%E5%88%86%E6%9E%90%EF%BC%9A%E8%BF%99%E6%9D%A1%E9%9A%A7%E9%81%93%E8%97%8F%E4%BA%86%E5%A4%9A%E5%B0%91%E7%A7%91%E6%8A%80%E7%A7%98%E5%AF%86%E2%80%94%E2%80%94%E6%8F%AD%E7%A7%98%22%E4%B8%87%E9%87%8C%E9%95%BF%E6%B1%9F%E5%85%AC%E9%93%81%E7%AC%AC%E4%B8%80%E9%9A%A7%22-%E6%96%B0%E5%8D%8E%E7%BD%91&rft_id=http%3A%2F%2Fwww.xinhuanet.com%2F2018-10%2F01%2Fc_129964700.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-46"><span class="mw-cite-backlink"><b><a href="#cite_ref-46">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREF汉网2018" class="citation web cs1">汉网 (27 September 2018). <a rel="nofollow" class="external text" href="https://news.sina.com.cn/o/2018-09-27/doc-ifxeuwwr8734437.shtml">"揭秘武汉长江公铁第一隧"尖板眼" 68个通道可供江底逃生"</a>. <i>news.sina.com.cn</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 June</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=news.sina.com.cn&rft.atitle=%E6%8F%AD%E7%A7%98%E6%AD%A6%E6%B1%89%E9%95%BF%E6%B1%9F%E5%85%AC%E9%93%81%E7%AC%AC%E4%B8%80%E9%9A%A7%22%E5%B0%96%E6%9D%BF%E7%9C%BC%22+68%E4%B8%AA%E9%80%9A%E9%81%93%E5%8F%AF%E4%BE%9B%E6%B1%9F%E5%BA%95%E9%80%83%E7%94%9F&rft.date=2018-09-27&rft.au=%E6%B1%89%E7%BD%91&rft_id=https%3A%2F%2Fnews.sina.com.cn%2Fo%2F2018-09-27%2Fdoc-ifxeuwwr8734437.shtml&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-47"><span class="mw-cite-backlink"><b><a href="#cite_ref-47">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://m.xinhuanet.com/hb/2018-09/19/c_1123450459.htm">"武汉长江公铁隧道工程打造全球"超级工程"样板-新华网"</a>. <i>m.xinhuanet.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">7 June</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=m.xinhuanet.com&rft.atitle=%E6%AD%A6%E6%B1%89%E9%95%BF%E6%B1%9F%E5%85%AC%E9%93%81%E9%9A%A7%E9%81%93%E5%B7%A5%E7%A8%8B%E6%89%93%E9%80%A0%E5%85%A8%E7%90%83%22%E8%B6%85%E7%BA%A7%E5%B7%A5%E7%A8%8B%22%E6%A0%B7%E6%9D%BF-%E6%96%B0%E5%8D%8E%E7%BD%91&rft_id=http%3A%2F%2Fm.xinhuanet.com%2Fhb%2F2018-09%2F19%2Fc_1123450459.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-48"><span class="mw-cite-backlink"><b><a href="#cite_ref-48">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.mnn.com/green-tech/transportation/stories/drive-through-these-10-tremendous-tunnels">"Drive through these 10 tremendous tunnels"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Drive+through+these+10+tremendous+tunnels&rft_id=https%3A%2F%2Fwww.mnn.com%2Fgreen-tech%2Ftransportation%2Fstories%2Fdrive-through-these-10-tremendous-tunnels&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-Mishra-49"><span class="mw-cite-backlink"><b><a href="#cite_ref-Mishra_49-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMishraAggarwalBerghmansFrijns2015" class="citation journal cs1">Mishra, V K; Aggarwal, M L; Berghmans, P; Frijns, E; Int Panis, L; Chacko, K M (2015). <a rel="nofollow" class="external text" href="https://www.researchgate.net/publication/284172320">"Dynamics of ultrafine particles inside a roadway tunnel"</a>. <i>Environmental Monitoring and Assessment</i>. <b>187</b> (12): 756. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2015EMnAs.187..756M">2015EMnAs.187..756M</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs10661-015-4948-x">10.1007/s10661-015-4948-x</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/26577216">26577216</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:207140116">207140116</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Environmental+Monitoring+and+Assessment&rft.atitle=Dynamics+of+ultrafine+particles+inside+a+roadway+tunnel&rft.volume=187&rft.issue=12&rft.pages=756&rft.date=2015&rft_id=info%3Adoi%2F10.1007%2Fs10661-015-4948-x&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A207140116%23id-name%3DS2CID&rft_id=info%3Apmid%2F26577216&rft_id=info%3Abibcode%2F2015EMnAs.187..756M&rft.aulast=Mishra&rft.aufirst=V+K&rft.au=Aggarwal%2C+M+L&rft.au=Berghmans%2C+P&rft.au=Frijns%2C+E&rft.au=Int+Panis%2C+L&rft.au=Chacko%2C+K+M&rft_id=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F284172320&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-50"><span class="mw-cite-backlink"><b><a href="#cite_ref-50">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKimRho2018" class="citation journal cs1">Kim, Joon-Hyung; Rho, Joo-Hyun (1 March 2018). "Pressure wave characteristics of a high-speed train in a tunnel according to the operating conditions". <i>Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit</i>. <b>232</b> (3): 928–935. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1177%2F0954409717702015">10.1177/0954409717702015</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0954-4097">0954-4097</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:125620030">125620030</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Proceedings+of+the+Institution+of+Mechanical+Engineers%2C+Part+F%3A+Journal+of+Rail+and+Rapid+Transit&rft.atitle=Pressure+wave+characteristics+of+a+high-speed+train+in+a+tunnel+according+to+the+operating+conditions&rft.volume=232&rft.issue=3&rft.pages=928-935&rft.date=2018-03-01&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A125620030%23id-name%3DS2CID&rft.issn=0954-4097&rft_id=info%3Adoi%2F10.1177%2F0954409717702015&rft.aulast=Kim&rft.aufirst=Joon-Hyung&rft.au=Rho%2C+Joo-Hyun&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-51"><span class="mw-cite-backlink"><b><a href="#cite_ref-51">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNiuZhouLiuYuan2018" class="citation journal cs1">Niu, Jiqiang; Zhou, Dan; Liu, Feng; Yuan, Yanping (1 October 2018). "Effect of train length on fluctuating aerodynamic pressure wave in tunnels and method for determining the amplitude of pressure wave on trains". <i>Tunnelling and Underground Space Technology</i>. <b>80</b>: 277–289. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2018TUSTI..80..277N">2018TUSTI..80..277N</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.tust.2018.07.031">10.1016/j.tust.2018.07.031</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0886-7798">0886-7798</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:116606435">116606435</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Tunnelling+and+Underground+Space+Technology&rft.atitle=Effect+of+train+length+on+fluctuating+aerodynamic+pressure+wave+in+tunnels+and+method+for+determining+the+amplitude+of+pressure+wave+on+trains&rft.volume=80&rft.pages=277-289&rft.date=2018-10-01&rft_id=info%3Adoi%2F10.1016%2Fj.tust.2018.07.031&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A116606435%23id-name%3DS2CID&rft.issn=0886-7798&rft_id=info%3Abibcode%2F2018TUSTI..80..277N&rft.aulast=Niu&rft.aufirst=Jiqiang&rft.au=Zhou%2C+Dan&rft.au=Liu%2C+Feng&rft.au=Yuan%2C+Yanping&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-52"><span class="mw-cite-backlink"><b><a href="#cite_ref-52">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFXiePengWangZhang2019" class="citation journal cs1">Xie, Pengpeng; Peng, Yong; Wang, Tiantian; Zhang, Honghao (April 2019). <a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6480231">"Risks of Ear Complaints of Passengers and Drivers While Trains Are Passing Through Tunnels at High Speed: A Numerical Simulation and Experimental Study"</a>. <i>International Journal of Environmental Research and Public Health</i>. <b>16</b> (7): 1283. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.3390%2Fijerph16071283">10.3390/ijerph16071283</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1661-7827">1661-7827</a>. <a href="/wiki/PMC_(identifier)" class="mw-redirect" title="PMC (identifier)">PMC</a> <span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6480231">6480231</a></span>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30974822">30974822</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=International+Journal+of+Environmental+Research+and+Public+Health&rft.atitle=Risks+of+Ear+Complaints+of+Passengers+and+Drivers+While+Trains+Are+Passing+Through+Tunnels+at+High+Speed%3A+A+Numerical+Simulation+and+Experimental+Study&rft.volume=16&rft.issue=7&rft.pages=1283&rft.date=2019-04&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC6480231%23id-name%3DPMC&rft.issn=1661-7827&rft_id=info%3Apmid%2F30974822&rft_id=info%3Adoi%2F10.3390%2Fijerph16071283&rft.aulast=Xie&rft.aufirst=Pengpeng&rft.au=Peng%2C+Yong&rft.au=Wang%2C+Tiantian&rft.au=Zhang%2C+Honghao&rft_id=https%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fpmc%2Farticles%2FPMC6480231&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-53"><span class="mw-cite-backlink"><b><a href="#cite_ref-53">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFridolfRonchiNilssonFrantzich2013" class="citation journal cs1">Fridolf, K.; Ronchi, E.; Nilsson, D.; Frantzich, H. (2013). "Movement speed and exit choice in smoke-filled rail tunnels". <i>Fire Safety Journal</i>. <b>59</b>: 8–21. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2013FirSJ..59....8F">2013FirSJ..59....8F</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.firesaf.2013.03.007">10.1016/j.firesaf.2013.03.007</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Fire+Safety+Journal&rft.atitle=Movement+speed+and+exit+choice+in+smoke-filled+rail+tunnels&rft.volume=59&rft.pages=8-21&rft.date=2013&rft_id=info%3Adoi%2F10.1016%2Fj.firesaf.2013.03.007&rft_id=info%3Abibcode%2F2013FirSJ..59....8F&rft.aulast=Fridolf&rft.aufirst=K.&rft.au=Ronchi%2C+E.&rft.au=Nilsson%2C+D.&rft.au=Frantzich%2C+H.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-54"><span class="mw-cite-backlink"><b><a href="#cite_ref-54">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJohnsonEdward_L._Thomas1999" class="citation journal cs1">Johnson, Christine M.; Edward L. Thomas (October 1999). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20130309164537/http://ntl.bts.gov/lib/jpodocs/repts_te/11063.pdf">"A Case Study Boston Central Artery/Tunnel Integrated Project Control System, Responding to incidents Rapidly and Effectively"</a> <span class="cs1-format">(PDF)</span>. <i>Metropolitan Transportation Management Center</i>: 12. Archived from <a rel="nofollow" class="external text" href="http://ntl.bts.gov/lib/jpodocs/repts_te/11063.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 9 March 2013<span class="reference-accessdate">. Retrieved <span class="nowrap">4 April</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Metropolitan+Transportation+Management+Center&rft.atitle=A+Case+Study+Boston+Central+Artery%2FTunnel+Integrated+Project+Control+System%2C+Responding+to+incidents+Rapidly+and+Effectively&rft.pages=12&rft.date=1999-10&rft.aulast=Johnson&rft.aufirst=Christine+M.&rft.au=Edward+L.+Thomas&rft_id=http%3A%2F%2Fntl.bts.gov%2Flib%2Fjpodocs%2Frepts_te%2F11063.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-55"><span class="mw-cite-backlink"><b><a href="#cite_ref-55">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHashashHookSchmidtYao2001" class="citation journal cs1">Hashash, Youssef M.A.; Hook, Jeffrey J.; Schmidt, Birger; Yao, John I-Chiang (2001). <a rel="nofollow" class="external text" href="https://www.sciencedirect.com/science/article/abs/pii/S0886779801000517">"Seismic design and analysis of underground structures"</a>. <i>Tunnelling and Underground Space Technology</i>. <b>16</b> (4): 247–293. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2001TUSTI..16..247H">2001TUSTI..16..247H</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2FS0886-7798%2801%2900051-7">10.1016/S0886-7798(01)00051-7</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:108456041">108456041</a> – via <a href="/wiki/Science_Direct" class="mw-redirect" title="Science Direct">Science Direct</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Tunnelling+and+Underground+Space+Technology&rft.atitle=Seismic+design+and+analysis+of+underground+structures&rft.volume=16&rft.issue=4&rft.pages=247-293&rft.date=2001&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A108456041%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1016%2FS0886-7798%2801%2900051-7&rft_id=info%3Abibcode%2F2001TUSTI..16..247H&rft.aulast=Hashash&rft.aufirst=Youssef+M.A.&rft.au=Hook%2C+Jeffrey+J.&rft.au=Schmidt%2C+Birger&rft.au=Yao%2C+John+I-Chiang&rft_id=https%3A%2F%2Fwww.sciencedirect.com%2Fscience%2Farticle%2Fabs%2Fpii%2FS0886779801000517&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-56"><span class="mw-cite-backlink"><b><a href="#cite_ref-56">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFNational_Geophysical_Data_Center_/_World_Data_Service_(NGDC/WDS):_NCEI/WDS_Global_Significant_Earthquake_Database._NOAA_National_Centers_for_Environmental_Information1972" class="citation web cs1">National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Global Significant Earthquake Database. NOAA National Centers for Environmental Information (1972). <a rel="nofollow" class="external text" href="https://www.ngdc.noaa.gov/hazel/view/hazards/earthquake/event-more-info/5372">"Significant Earthquake Information"</a>. NOAA National Centers for Environmental Information. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.7289%2FV5TD9V7K">10.7289/V5TD9V7K</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Significant+Earthquake+Information&rft.pub=NOAA+National+Centers+for+Environmental+Information&rft.date=1972&rft_id=info%3Adoi%2F10.7289%2FV5TD9V7K&rft.au=National+Geophysical+Data+Center+%2F+World+Data+Service+%28NGDC%2FWDS%29%3A+NCEI%2FWDS+Global+Significant+Earthquake+Database.+NOAA+National+Centers+for+Environmental+Information&rft_id=https%3A%2F%2Fwww.ngdc.noaa.gov%2Fhazel%2Fview%2Fhazards%2Fearthquake%2Fevent-more-info%2F5372&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-57"><span class="mw-cite-backlink"><b><a href="#cite_ref-57">^</a></b></span> <span class="reference-text">Hymon, Steve. "Designing A Subway to Withstand an Earthquake." The Source. N.p., 2017. Web. 11 November 2017. <a rel="nofollow" class="external free" href="http://thesource.metro.net/2012/08/10/designing-a-subway-to-withstand-an-earthquake/">http://thesource.metro.net/2012/08/10/designing-a-subway-to-withstand-an-earthquake/</a></span> </li> <li id="cite_note-58"><span class="mw-cite-backlink"><b><a href="#cite_ref-58">^</a></b></span> <span class="reference-text">Klaus Grewe, 1998, Licht am Ende des Tunnels – Planung und Trassierung im antiken Tunnelbau, Verlag Philipp von Zabern, Mainz am Rhein.</span> </li> <li id="cite_note-59"><span class="mw-cite-backlink"><b><a href="#cite_ref-59">^</a></b></span> <span class="reference-text">Siamak Hashemi, 2013, The Magnificence of Civilization in Depths of Ground (A Review of Underground Structures in Iran – Past to Present), Shadrang Printing and Publishing Co., Tehran.</span> </li> <li id="cite_note-60"><span class="mw-cite-backlink"><b><a href="#cite_ref-60">^</a></b></span> <span class="reference-text">UNESCO World Heritage Centre – World Heritage List: Qanats of Gonabad, Date of Inscription 2007, Reference No. 5207, At: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://whc.unesco.org/fr/listesindicatives/5207">"Qanats of Gonabad – UNESCO World Heritage Centre"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160329120845/https://whc.unesco.org/fr/listesindicatives/5207">Archived</a> from the original on 29 March 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">14 December</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Qanats+of+Gonabad+%E2%80%93+UNESCO+World+Heritage+Centre&rft_id=https%3A%2F%2Fwhc.unesco.org%2Ffr%2Flistesindicatives%2F5207&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-61"><span class="mw-cite-backlink"><b><a href="#cite_ref-61">^</a></b></span> <span class="reference-text">Schmidt, E.F., 1953, Persepolis I – Structures, Reliefs, Inscriptions; The University of Chicago Oriental Institute Publications, Volume LXVIII, The University of Chicago Press.</span> </li> <li id="cite_note-62"><span class="mw-cite-backlink"><b><a href="#cite_ref-62">^</a></b></span> <span class="reference-text">Blogcu <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://terelek.blogcu.com/terelek-kaya-tuneli/319497">"TERELEK KAYA TÜNELİ – terelek"</a>. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160327222549/http://terelek.blogcu.com/terelek-kaya-tuneli/319497">Archived</a> from the original on 27 March 2016<span class="reference-accessdate">. Retrieved <span class="nowrap">17 July</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=TERELEK+KAYA+T%C3%9CNEL%C4%B0+%E2%80%93+terelek&rft_id=http%3A%2F%2Fterelek.blogcu.com%2Fterelek-kaya-tuneli%2F319497&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-63"><span class="mw-cite-backlink"><b><a href="#cite_ref-63">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.dudleycanaltrust.org.uk/interactive-tour-map/">Map of Dudley Canals | Discover Black Country Canals</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20150409192053/http://www.dudleycanaltrust.org.uk/interactive-tour-map/">Archived</a> 9 April 2015 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span> </li> <li id="cite_note-listedbuilding1422984-64"><span class="mw-cite-backlink"><b><a href="#cite_ref-listedbuilding1422984_64-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHistoric_England1422984" class="citation web cs1"><a href="/wiki/Historic_England" title="Historic England">Historic England</a>. <a rel="nofollow" class="external text" href="https://HistoricEngland.org.uk/listing/the-list/list-entry/1422984?section=official-list-entry">"Fritchley Tunnel, Butterley Gangroad (1422984)"</a>. <i><a href="/wiki/National_Heritage_List_for_England" title="National Heritage List for England">National Heritage List for England</a></i><span class="reference-accessdate">. Retrieved <span class="nowrap">19 March</span> 2015</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=National+Heritage+List+for+England&rft.atitle=Fritchley+Tunnel%2C+Butterley+Gangroad+%281422984%29&rft.au=Historic+England&rft_id=https%3A%2F%2FHistoricEngland.org.uk%2Flisting%2Fthe-list%2Flist-entry%2F1422984%3Fsection%3Dofficial-list-entry&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-BBC22342239-65"><span class="mw-cite-backlink"><b><a href="#cite_ref-BBC22342239_65-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation news cs1"><a rel="nofollow" class="external text" href="https://www.bbc.co.uk/news/uk-england-derbyshire-22342239">"Archaeologists find 'world's oldest railway tunnel' in Derbyshire"</a>. <i>BBC News</i>. 1 May 2013.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=BBC+News&rft.atitle=Archaeologists+find+%27world%27s+oldest+railway+tunnel%27+in+Derbyshire&rft.date=2013-05-01&rft_id=https%3A%2F%2Fwww.bbc.co.uk%2Fnews%2Fuk-england-derbyshire-22342239&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-66"><span class="mw-cite-backlink"><b><a href="#cite_ref-66">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.cromfordcanal.info">Friends of the Cromford Canal – HOME</a><a rel="nofollow" class="external text" href="https://web.archive.org/web/20161023115647/http://www.cromfordcanal.info/">Archived</a> 23 October 2016 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span> </li> <li id="cite_note-67"><span class="mw-cite-backlink"><b><a href="#cite_ref-67">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.britishlistedbuildings.co.uk/en-507533-bourne-s-tunnel-at-sj5033491804-">"Bourne's Tunnel at Sj5033491804 – Saint Helens – St Helens – England"</a>. <i>British Listed Buildings</i><span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=British+Listed+Buildings&rft.atitle=Bourne%27s+Tunnel+at+Sj5033491804+%E2%80%93+Saint+Helens+%E2%80%93+St+Helens+%E2%80%93+England&rft_id=http%3A%2F%2Fwww.britishlistedbuildings.co.uk%2Fen-507533-bourne-s-tunnel-at-sj5033491804-&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-68"><span class="mw-cite-backlink"><b><a href="#cite_ref-68">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20090517123220/http://www.liverpoolwiki.org/Liverpool%27s_Historic_Rail_Tunnels">"Liverpool's Historic Rail Tunnels"</a>. The Liverpool Wiki. 22 February 1999. Archived from <a rel="nofollow" class="external text" href="http://www.liverpoolwiki.org/Liverpool%27s_Historic_Rail_Tunnels">the original</a> on 17 May 2009<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Liverpool%27s+Historic+Rail+Tunnels&rft.pub=The+Liverpool+Wiki&rft.date=1999-02-22&rft_id=http%3A%2F%2Fwww.liverpoolwiki.org%2FLiverpool%2527s_Historic_Rail_Tunnels&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-subbrit.org.uk-69"><span class="mw-cite-backlink">^ <a href="#cite_ref-subbrit.org.uk_69-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-subbrit.org.uk_69-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.subbrit.org.uk/sb-sites/sites/l/liverpool_edge_hill_cutting/index3.shtml">"Subterranea Britannica: Sites"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Subterranea+Britannica%3A+Sites&rft_id=http%3A%2F%2Fwww.subbrit.org.uk%2Fsb-sites%2Fsites%2Fl%2Fliverpool_edge_hill_cutting%2Findex3.shtml&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-70"><span class="mw-cite-backlink"><b><a href="#cite_ref-70">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.forgottenrelics.co.uk/tunnels/gallery/wapping.html">"Wapping Tunnel"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Wapping+Tunnel&rft_id=http%3A%2F%2Fwww.forgottenrelics.co.uk%2Ftunnels%2Fgallery%2Fwapping.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-maund-71"><span class="mw-cite-backlink"><b><a href="#cite_ref-maund_71-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMaund,_T.B.2001" class="citation book cs1">Maund, T.B. (2001). <i>Merseyrail electrics: the inside story</i>. Sheffield: NBC Books. <a href="/wiki/OCLC_(identifier)" class="mw-redirect" title="OCLC (identifier)">OCLC</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/oclc/655126526">655126526</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Merseyrail+electrics%3A+the+inside+story&rft.place=Sheffield&rft.pub=NBC+Books&rft.date=2001&rft_id=info%3Aoclcnum%2F655126526&rft.au=Maund%2C+T.B.&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-72"><span class="mw-cite-backlink"><b><a href="#cite_ref-72">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.hows.org.uk/personal/rail/incline/lls.htm">Liverpool Lime St</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20160304031133/http://www.hows.org.uk/personal/rail/incline/lls.htm">Archived</a> 4 March 2016 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span> </li> <li id="cite_note-73"><span class="mw-cite-backlink"><b><a href="#cite_ref-73">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.forgottenrelics.co.uk/tunnels/gallery/victoria.html">"Victoria Tunnel"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Victoria+Tunnel&rft_id=http%3A%2F%2Fwww.forgottenrelics.co.uk%2Ftunnels%2Fgallery%2Fvictoria.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-74"><span class="mw-cite-backlink"><b><a href="#cite_ref-74">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.forgottenrelics.co.uk/tunnels/gallery/waterloo.html">"Waterloo Tunnel"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Waterloo+Tunnel&rft_id=http%3A%2F%2Fwww.forgottenrelics.co.uk%2Ftunnels%2Fgallery%2Fwaterloo.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-75"><span class="mw-cite-backlink"><b><a href="#cite_ref-75">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130529074903/http://www.upton-wirral.co.uk/wir2.php">"Mersey Railway Tunnel"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.upton-wirral.co.uk/wir2.php">the original</a> on 29 May 2013<span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mersey+Railway+Tunnel&rft_id=http%3A%2F%2Fwww.upton-wirral.co.uk%2Fwir2.php&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-76"><span class="mw-cite-backlink"><b><a href="#cite_ref-76">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1151">Engineering Timelines – Mersey Railway</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20120322113859/http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1151">Archived</a> 22 March 2012 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span> </li> <li id="cite_note-nrhp_stclair-77"><span class="mw-cite-backlink">^ <a href="#cite_ref-nrhp_stclair_77-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-nrhp_stclair_77-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLange1993" class="citation web cs1">Lange, Robie S. (February 1993). <a rel="nofollow" class="external text" href="https://npgallery.nps.gov/NRHP/GetAsset/NHLS/70000684_text">"National Register of Historic Places Inventory-Nomination: St. Clair River Tunnel / St. Clair Railroad Tunnel"</a>. <i>National Park Service</i><span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=National+Park+Service&rft.atitle=National+Register+of+Historic+Places+Inventory-Nomination%3A+St.+Clair+River+Tunnel+%2F+St.+Clair+Railroad+Tunnel&rft.date=1993-02&rft.aulast=Lange&rft.aufirst=Robie+S.&rft_id=https%3A%2F%2Fnpgallery.nps.gov%2FNRHP%2FGetAsset%2FNHLS%2F70000684_text&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-78"><span class="mw-cite-backlink"><b><a href="#cite_ref-78">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.tu.no/artikler/i-dag-sprenges-siste-fjellrest-vekk-i-verdens-lengste-undersjoiske-veitunnel/410538">"Nå er siste fjellrest sprengt vekk i verdens lengste undersjøiske veitunnel"</a>. 26 October 2017.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=N%C3%A5+er+siste+fjellrest+sprengt+vekk+i+verdens+lengste+undersj%C3%B8iske+veitunnel&rft.date=2017-10-26&rft_id=https%3A%2F%2Fwww.tu.no%2Fartikler%2Fi-dag-sprenges-siste-fjellrest-vekk-i-verdens-lengste-undersjoiske-veitunnel%2F410538&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-79"><span class="mw-cite-backlink"><b><a href="#cite_ref-79">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120317104705/http://www.tunnelintelligence.com/safety-in-detail-106.html">"Safety: World's Deepest Subsea Tunnel Opens in Norway"</a>. <i>www.tunnelintelligence.com</i>. 2 March 2008. Archived from the original on 17 March 2012<span class="reference-accessdate">. Retrieved <span class="nowrap">23 January</span> 2024</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.tunnelintelligence.com&rft.atitle=Safety%3A+World%27s+Deepest+Subsea+Tunnel+Opens+in+Norway&rft.date=2008-03-02&rft_id=http%3A%2F%2Fwww.tunnelintelligence.com%2Fsafety-in-detail-106.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span><span class="cs1-maint citation-comment"><code class="cs1-code">{{<a href="/wiki/Template:Cite_web" title="Template:Cite web">cite web</a>}}</code>: CS1 maint: unfit URL (<a href="/wiki/Category:CS1_maint:_unfit_URL" title="Category:CS1 maint: unfit URL">link</a>)</span></span> </li> <li id="cite_note-80"><span class="mw-cite-backlink"><b><a href="#cite_ref-80">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.nce.co.uk/news/transport/costain-finishes-gerrards-cross-tunnel-rebuild/5218141.article">"Costain finishes Gerrards Cross tunnel rebuild"</a>. 19 May 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">30 September</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Costain+finishes+Gerrards+Cross+tunnel+rebuild&rft.date=2010-05-19&rft_id=http%3A%2F%2Fwww.nce.co.uk%2Fnews%2Ftransport%2Fcostain-finishes-gerrards-cross-tunnel-rebuild%2F5218141.article&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-81"><span class="mw-cite-backlink"><b><a href="#cite_ref-81">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKensinger2021" class="citation web cs1">Kensinger, Nathan (22 April 2021). <span class="id-lock-registration" title="Free registration required"><a rel="nofollow" class="external text" href="https://gothamist.com/news/nycs-giant-water-tunnel-begins-work-on-final-shafts-following-50-years-of-construction">"NYC's Giant Water Tunnel Begins Work On Final Shafts, Following 50 Years Of Construction"</a></span>. <i>Gothamist</i><span class="reference-accessdate">. Retrieved <span class="nowrap">15 September</span> 2022</span>. <q>These last two shafts are now expected to be done by 2026, according to the DEP, but the tunnel still won't be complete. The original plans called for one more extension—a 14-mile conduit between Yonkers, the Bronx and Queens.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Gothamist&rft.atitle=NYC%27s+Giant+Water+Tunnel+Begins+Work+On+Final+Shafts%2C+Following+50+Years+Of+Construction&rft.date=2021-04-22&rft.aulast=Kensinger&rft.aufirst=Nathan&rft_id=https%3A%2F%2Fgothamist.com%2Fnews%2Fnycs-giant-water-tunnel-begins-work-on-final-shafts-following-50-years-of-construction&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-82"><span class="mw-cite-backlink"><b><a href="#cite_ref-82">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20070621120811/http://www.nyc.gov/html/dep/html/news/3rdtunnel.html">"City Water Tunnel No. 3"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.nyc.gov/html/dep/html/news/3rdtunnel.html">the original</a> on 21 June 2007<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=City+Water+Tunnel+No.+3&rft_id=http%3A%2F%2Fwww.nyc.gov%2Fhtml%2Fdep%2Fhtml%2Fnews%2F3rdtunnel.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-83"><span class="mw-cite-backlink"><b><a href="#cite_ref-83">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110517201322/http://www.youtube.com/watch?v=kp1EFlngjKQ">"Glenbrook Tunnel – Alcatraz Down Under – History Channel"</a>. Youtube.com. Archived from <a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=kp1EFlngjKQ">the original</a> on 17 May 2011<span class="reference-accessdate">. Retrieved <span class="nowrap">19 April</span> 2013</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Glenbrook+Tunnel+%E2%80%93+Alcatraz+Down+Under+%E2%80%93+History+Channel&rft.pub=Youtube.com&rft_id=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dkp1EFlngjKQ&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-84"><span class="mw-cite-backlink"><b><a href="#cite_ref-84">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://bluemountains.yourguide.com.au/news/local/news/general/author-lifts-lid-on-chemical-wartime-history/307763.aspx">Author lifts lid on chemical wartime history – Local News – News – General – Blue Mountains Gazette</a> <a rel="nofollow" class="external text" href="https://web.archive.org/web/20090109001520/http://bluemountains.yourguide.com.au/news/local/news/general/author-lifts-lid-on-chemical-wartime-history/307763.aspx">Archived</a> 9 January 2009 at the <a href="/wiki/Wayback_Machine" title="Wayback Machine">Wayback Machine</a></span> </li> <li id="cite_note-Audi-85"><span class="mw-cite-backlink">^ <a href="#cite_ref-Audi_85-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Audi_85-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAudi2013" class="citation news cs1">Audi, Tamara (31 January 2013). <a rel="nofollow" class="external text" href="https://online.wsj.com/news/articles/SB10001424127887323854904578264382749570570">"Drug Tunnels Have Feds Digging for Answers"</a>. <i>The Wall Street Journal</i><span class="reference-accessdate">. Retrieved <span class="nowrap">4 October</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Wall+Street+Journal&rft.atitle=Drug+Tunnels+Have+Feds+Digging+for+Answers&rft.date=2013-01-31&rft.aulast=Audi&rft.aufirst=Tamara&rft_id=https%3A%2F%2Fonline.wsj.com%2Fnews%2Farticles%2FSB10001424127887323854904578264382749570570&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-Colchester-86"><span class="mw-cite-backlink"><b><a href="#cite_ref-Colchester_86-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFColchester2010" class="citation news cs1">Colchester, Max (31 March 2010). <a rel="nofollow" class="external text" href="https://online.wsj.com/articles/SB10001424052702304739104575153530631794248">"Thieves Drill Into Paris Bank Vault"</a>. <i>The Wall Street Journal</i><span class="reference-accessdate">. Retrieved <span class="nowrap">4 October</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Wall+Street+Journal&rft.atitle=Thieves+Drill+Into+Paris+Bank+Vault&rft.date=2010-03-31&rft.aulast=Colchester&rft.aufirst=Max&rft_id=https%3A%2F%2Fonline.wsj.com%2Farticles%2FSB10001424052702304739104575153530631794248&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-Evans-87"><span class="mw-cite-backlink"><b><a href="#cite_ref-Evans_87-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFEvans2014" class="citation news cs1">Evans, Peter (3 October 2014). <a rel="nofollow" class="external text" href="https://online.wsj.com/articles/where-criminal-underworld-is-more-than-a-euphemism-1412383000">"Where 'Criminal Underworld' Is More Than a Euphemism"</a>. <i>The Wall Street Journal</i><span class="reference-accessdate">. Retrieved <span class="nowrap">4 October</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=The+Wall+Street+Journal&rft.atitle=Where+%27Criminal+Underworld%27+Is+More+Than+a+Euphemism&rft.date=2014-10-03&rft.aulast=Evans&rft.aufirst=Peter&rft_id=https%3A%2F%2Fonline.wsj.com%2Farticles%2Fwhere-criminal-underworld-is-more-than-a-euphemism-1412383000&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-arniatunnel-88"><span class="mw-cite-backlink"><b><a href="#cite_ref-arniatunnel_88-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKhajuria" class="citation news cs1">Khajuria, Ravi Krishnan. <a rel="nofollow" class="external text" href="http://www.hindustantimes.com/india-news/under-construction-tunnel-being-dug-from-pakistan-side-unearthed-by-bsf-in-jammu/story-B1qgulsJCMQ8FOxWs3LYyO.html">"Day after India-Pakistan flag meet, BSF detects trans-border tunnel in Jammu's Arnia sub-sector"</a>. <i><a href="/wiki/Hindustan_Times" title="Hindustan Times">Hindustan Times</a></i>. 1 October 2017<span class="reference-accessdate">. Retrieved <span class="nowrap">10 December</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Hindustan+Times&rft.atitle=Day+after+India-Pakistan+flag+meet%2C+BSF+detects+trans-border+tunnel+in+Jammu%27s+Arnia+sub-sector&rft.aulast=Khajuria&rft.aufirst=Ravi+Krishnan&rft_id=http%3A%2F%2Fwww.hindustantimes.com%2Findia-news%2Funder-construction-tunnel-being-dug-from-pakistan-side-unearthed-by-bsf-in-jammu%2Fstory-B1qgulsJCMQ8FOxWs3LYyO.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-sambhatunnel-89"><span class="mw-cite-backlink"><b><a href="#cite_ref-sambhatunnel_89-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFIqbal2017" class="citation news cs1">Iqbal, Sheikh Zaffar (14 February 2017). <a rel="nofollow" class="external text" href="https://www.ndtv.com/india-news/20-foot-tunnel-from-pakistan-found-by-bsf-at-sambha-jammu-and-kashmir-1659393">"20-Foot Tunnel From Pakistan Found By BSF At Sambha, Jammu and Kashmir"</a>. <i><a href="/wiki/NDTV" title="NDTV">NDTV</a></i><span class="reference-accessdate">. Retrieved <span class="nowrap">10 December</span> 2017</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=NDTV&rft.atitle=20-Foot+Tunnel+From+Pakistan+Found+By+BSF+At+Sambha%2C+Jammu+and+Kashmir&rft.date=2017-02-14&rft.aulast=Iqbal&rft.aufirst=Sheikh+Zaffar&rft_id=https%3A%2F%2Fwww.ndtv.com%2Findia-news%2F20-foot-tunnel-from-pakistan-found-by-bsf-at-sambha-jammu-and-kashmir-1659393&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> <li id="cite_note-90"><span class="mw-cite-backlink"><b><a href="#cite_ref-90">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWarholm2014" class="citation news cs1 cs1-prop-foreign-lang-source">Warholm, Harald (10 November 2014). <a rel="nofollow" class="external text" href="http://www.nrk.no/nordland/jubler-over-sjeldent-blinkskudd-av-fjellet-torghatten-1.12034377">"Hobbyfotografen har ventet tre år på dette sjeldne blinkskuddet"</a> [The hobby photographer has waited three years for this rare shot]. <i>nrk.no</i> (in Norwegian)<span class="reference-accessdate">. Retrieved <span class="nowrap">13 November</span> 2014</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=nrk.no&rft.atitle=Hobbyfotografen+har+ventet+tre+%C3%A5r+p%C3%A5+dette+sjeldne+blinkskuddet&rft.date=2014-11-10&rft.aulast=Warholm&rft.aufirst=Harald&rft_id=http%3A%2F%2Fwww.nrk.no%2Fnordland%2Fjubler-over-sjeldent-blinkskudd-av-fjellet-torghatten-1.12034377&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Bibliography">Bibliography</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=35" title="Edit section: Bibliography"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFEllis2015" class="citation book cs1">Ellis, Iain W (2015). <i>Ellis' British Railway Engineering Encyclopaedia</i> (3rd Revised ed.). Lulu.com. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-1-326-01063-8" title="Special:BookSources/978-1-326-01063-8"><bdi>978-1-326-01063-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Ellis%27+British+Railway+Engineering+Encyclopaedia&rft.edition=3rd+Revised&rft.pub=Lulu.com&rft.date=2015&rft.isbn=978-1-326-01063-8&rft.aulast=Ellis&rft.aufirst=Iain+W&rfr_id=info%3Asid%2Fen.wikipedia.org%3ATunnel" class="Z3988"></span></li> <li>Railway Tunnels in Queensland by Brian Webber, 1997, <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-909937-33-8" title="Special:BookSources/0-909937-33-8">0-909937-33-8</a>.</li> <li>Sullivan, Walter. <a rel="nofollow" class="external text" href="https://www.nytimes.com/1986/06/24/science/progress-in-technology-revives-interest-in-great-tunnels.html?&pagewanted=all">Progress In Technology Revives Interest In Great Tunnels</a>, <a href="/wiki/New_York_Times" class="mw-redirect" title="New York Times">New York Times</a>, 24 June 1986. Retrieved 15 August 2010.</li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Tunnel&action=edit&section=36" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/38px-Wikisource-logo.svg.png" decoding="async" width="38" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/57px-Wikisource-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/76px-Wikisource-logo.svg.png 2x" data-file-width="410" data-file-height="430" /></span></span></div> <div class="side-box-text plainlist"><a href="/wiki/Wikisource" title="Wikisource">Wikisource</a> has the text of the 1879 <i><a href="/wiki/American_Cyclop%C3%A6dia" class="mw-redirect" title="American Cyclopædia">American Cyclopædia</a></i> article <i><b><a href="https://en.wikisource.org/wiki/The_American_Cyclop%C3%A6dia_(1879)/Tunnel" class="extiw" title="s:The American Cyclopædia (1879)/Tunnel">Tunnel</a></b></i>.</div></div> </div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1235681985"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1237033735"><div class="side-box side-box-right plainlinks sistersitebox"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" decoding="async" width="30" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span></div> <div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Tunnels" class="extiw" title="commons:Category:Tunnels">Tunnels</a></span>.</div></div> </div> <ul><li><a rel="nofollow" class="external text" href="http://www.ita-aites.org/">ITA-AITES International Tunnelling Association</a></li> <li><a rel="nofollow" class="external text" href="http://www.tunnelsonline.info/">Tunnels & Tunnelling International magazine</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl 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(structure)">Theater</a></li> <li><a href="/wiki/Urban_park" title="Urban park">Urban park</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Geotechnical_engineering" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Geotechnical_engineering" title="Template:Geotechnical engineering"><abbr title="View this 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class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;">Field (<i>in situ</i>)</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"><div class="div-col" style="column-width: 33em;"> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Core_sample.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Core_sample.svg/20px-Core_sample.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Core_sample.svg/30px-Core_sample.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5e/Core_sample.svg/40px-Core_sample.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Core_drill" title="Core drill">Core drill</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Cone_penetration_test.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/28/Cone_penetration_test.svg/20px-Cone_penetration_test.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/28/Cone_penetration_test.svg/30px-Cone_penetration_test.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/28/Cone_penetration_test.svg/40px-Cone_penetration_test.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Cone_penetration_test" title="Cone penetration test">Cone penetration test</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Geo-electrical_sounding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/10/Geo-electrical_sounding.svg/20px-Geo-electrical_sounding.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/10/Geo-electrical_sounding.svg/30px-Geo-electrical_sounding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/10/Geo-electrical_sounding.svg/40px-Geo-electrical_sounding.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/w/index.php?title=Geo-electrical_sounding&action=edit&redlink=1" class="new" title="Geo-electrical sounding (page does not exist)">Geo-electrical sounding</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:In_situ_permeameter_test.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/7b/In_situ_permeameter_test.svg/20px-In_situ_permeameter_test.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/7b/In_situ_permeameter_test.svg/30px-In_situ_permeameter_test.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/7b/In_situ_permeameter_test.svg/40px-In_situ_permeameter_test.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Permeability_(Earth_sciences)" class="mw-redirect" title="Permeability (Earth sciences)">Permeability test</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Load_test.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Load_test.svg/20px-Load_test.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Load_test.svg/30px-Load_test.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Load_test.svg/40px-Load_test.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Load_test" class="mw-redirect" title="Load test">Load test</a> <ul><li><a href="/wiki/Static_load_testing" title="Static load testing">Static</a></li> <li><a href="/wiki/Dynamic_load_testing" title="Dynamic load testing">Dynamic</a></li> <li><a href="/wiki/Statnamic_load_test" title="Statnamic load test">Statnamic</a></li></ul></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Pore_pressure_measurement.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Pore_pressure_measurement.svg/20px-Pore_pressure_measurement.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Pore_pressure_measurement.svg/30px-Pore_pressure_measurement.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Pore_pressure_measurement.svg/40px-Pore_pressure_measurement.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> Pore pressure measurement <ul><li><a href="/wiki/Piezometer" class="mw-redirect" title="Piezometer">Piezometer</a></li> <li><a href="/wiki/Well#Classification" title="Well">Well</a></li></ul></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Ram_sounding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Ram_sounding.svg/20px-Ram_sounding.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Ram_sounding.svg/30px-Ram_sounding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Ram_sounding.svg/40px-Ram_sounding.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/w/index.php?title=Ram_sounding&action=edit&redlink=1" class="new" title="Ram sounding (page does not exist)">Ram sounding</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Rock_control_drilling.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Rock_control_drilling.svg/20px-Rock_control_drilling.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Rock_control_drilling.svg/30px-Rock_control_drilling.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Rock_control_drilling.svg/40px-Rock_control_drilling.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/w/index.php?title=Rock_control_drilling&action=edit&redlink=1" class="new" title="Rock control drilling (page does not exist)">Rock control drilling</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Rotary_pressure_sounding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/81/Rotary_pressure_sounding.svg/20px-Rotary_pressure_sounding.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/81/Rotary_pressure_sounding.svg/30px-Rotary_pressure_sounding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/81/Rotary_pressure_sounding.svg/40px-Rotary_pressure_sounding.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Rotary-pressure_sounding" title="Rotary-pressure sounding">Rotary-pressure sounding</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Rotary_weight_sounding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Rotary_weight_sounding.svg/20px-Rotary_weight_sounding.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Rotary_weight_sounding.svg/30px-Rotary_weight_sounding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Rotary_weight_sounding.svg/40px-Rotary_weight_sounding.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/w/index.php?title=Rotary_weight_sounding&action=edit&redlink=1" class="new" title="Rotary weight sounding (page does not exist)">Rotary weight sounding</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Sample_series.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/05/Sample_series.svg/20px-Sample_series.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/05/Sample_series.svg/30px-Sample_series.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/05/Sample_series.svg/40px-Sample_series.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Soil_test#Soil_testing" title="Soil test">Sample series</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Screw_plate_test.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/75/Screw_plate_test.svg/20px-Screw_plate_test.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/75/Screw_plate_test.svg/30px-Screw_plate_test.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/75/Screw_plate_test.svg/40px-Screw_plate_test.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/w/index.php?title=Screw_plate_test&action=edit&redlink=1" class="new" title="Screw plate test (page does not exist)">Screw plate test</a></li></ul> <ul><li><a href="/wiki/Deformation_monitoring" title="Deformation monitoring">Deformation monitoring</a> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Inclinometer.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Inclinometer.svg/20px-Inclinometer.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Inclinometer.svg/30px-Inclinometer.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c6/Inclinometer.svg/40px-Inclinometer.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Inclinometer" title="Inclinometer">Inclinometer</a></li> <li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Settlement_recordings.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/35/Settlement_recordings.svg/20px-Settlement_recordings.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/35/Settlement_recordings.svg/30px-Settlement_recordings.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/35/Settlement_recordings.svg/40px-Settlement_recordings.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Soil_consolidation" title="Soil consolidation">Settlement recordings</a></li></ul></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Shear_vane_test.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Shear_vane_test.svg/20px-Shear_vane_test.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Shear_vane_test.svg/30px-Shear_vane_test.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/ae/Shear_vane_test.svg/40px-Shear_vane_test.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Shear_vane_test" title="Shear vane test">Shear vane test</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Simple_sounding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Simple_sounding.svg/20px-Simple_sounding.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Simple_sounding.svg/30px-Simple_sounding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d4/Simple_sounding.svg/40px-Simple_sounding.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/w/index.php?title=Simple_sounding&action=edit&redlink=1" class="new" title="Simple sounding (page does not exist)">Simple sounding</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Standard_penetration_test.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0d/Standard_penetration_test.svg/20px-Standard_penetration_test.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/0d/Standard_penetration_test.svg/30px-Standard_penetration_test.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/0d/Standard_penetration_test.svg/40px-Standard_penetration_test.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Standard_penetration_test" title="Standard penetration test">Standard penetration test</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Total_sounding.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/60/Total_sounding.svg/20px-Total_sounding.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/60/Total_sounding.svg/30px-Total_sounding.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/60/Total_sounding.svg/40px-Total_sounding.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Total_sounding" title="Total sounding">Total sounding</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Trial_pit.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/71/Trial_pit.svg/20px-Trial_pit.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/71/Trial_pit.svg/30px-Trial_pit.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/71/Trial_pit.svg/40px-Trial_pit.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Trial_pit" title="Trial pit">Trial pit</a></li></ul> <ul><li><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Visible_rock.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/14/Visible_rock.svg/20px-Visible_rock.svg.png" decoding="async" width="20" height="20" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/14/Visible_rock.svg/30px-Visible_rock.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/14/Visible_rock.svg/40px-Visible_rock.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span> <a href="/wiki/Bedrock" title="Bedrock">Visible bedrock</a></li></ul> <ul><li><a href="/wiki/Nuclear_densometer" class="mw-redirect" title="Nuclear densometer">Nuclear densometer test</a></li></ul> <ul><li><a href="/wiki/Exploration_geophysics" title="Exploration geophysics">Exploration geophysics</a></li></ul> <ul><li><a href="/wiki/Crosshole_sonic_logging" title="Crosshole sonic logging">Crosshole sonic logging</a></li></ul> <ul><li><a href="/wiki/Pile_integrity_test" title="Pile integrity test">Pile integrity test</a></li></ul> <ul><li><a href="/wiki/Wave_equation_analysis" title="Wave equation analysis">Wave equation analysis</a></li></ul></div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;"><a href="/wiki/Soil_test" title="Soil test">Laboratory <br />testing</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <li><a href="/wiki/Soil_classification" title="Soil classification">Soil classification</a></li> <li><a href="/wiki/Atterberg_limits" title="Atterberg limits">Atterberg limits</a></li> <li><a href="/wiki/California_bearing_ratio" title="California bearing ratio">California bearing ratio</a></li> <li><a href="/wiki/Direct_shear_test" title="Direct shear test">Direct shear test</a></li> <li><a href="/wiki/Hydrometer" title="Hydrometer">Hydrometer</a></li> <li><a href="/wiki/Proctor_compaction_test" title="Proctor compaction test">Proctor compaction test</a></li> <li><a href="/wiki/R-value_(soils)" title="R-value (soils)">R-value</a></li> <li><a href="/wiki/Sieve_analysis" title="Sieve analysis">Sieve analysis</a></li> <li><a href="/wiki/Triaxial_shear_test" title="Triaxial shear test">Triaxial shear test</a></li> <li><a href="/wiki/Oedometer_test" title="Oedometer test">Oedometer test</a></li> <li><a href="/wiki/Hydraulic_conductivity#Experimental_approach" title="Hydraulic conductivity">Hydraulic conductivity tests</a></li> <li><a href="/wiki/Water_content#Measurement" title="Water content">Water content tests</a></li> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Soil" title="Soil">Soil</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;">Types</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Clay" title="Clay">Clay</a></li> <li><a href="/wiki/Silt" title="Silt">Silt</a></li> <li><a href="/wiki/Sand" title="Sand">Sand</a></li> <li><a href="/wiki/Gravel" title="Gravel">Gravel</a></li> <li><a href="/wiki/Peat" title="Peat">Peat</a></li> <li><a href="/wiki/Loam" title="Loam">Loam</a></li> <li><a href="/wiki/Loess" title="Loess">Loess</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;">Properties</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Hydraulic_conductivity" title="Hydraulic conductivity">Hydraulic conductivity</a></li> <li><a href="/wiki/Water_content" title="Water content">Water content</a></li> <li><a href="/wiki/Void_ratio" title="Void ratio">Void ratio</a></li> <li><a href="/wiki/Bulk_density" title="Bulk density">Bulk density</a></li> <li><a href="/wiki/Thixotropy" title="Thixotropy">Thixotropy</a></li> <li><a href="/wiki/Reynolds%27_dilatancy" class="mw-redirect" title="Reynolds' dilatancy">Reynolds' dilatancy</a></li> <li><a href="/wiki/Angle_of_repose" title="Angle of repose">Angle of repose</a></li> <li><a href="/wiki/Friction#Angle_of_friction" title="Friction">Friction angle</a></li> <li><a href="/wiki/Cohesion_(geology)" title="Cohesion (geology)">Cohesion</a></li> <li><a href="/wiki/Porosity" title="Porosity">Porosity</a></li> <li><a href="/wiki/Permeability_(earth_sciences)" class="mw-redirect" title="Permeability (earth sciences)">Permeability</a></li> <li><a href="/wiki/Specific_storage" title="Specific storage">Specific storage</a></li> <li><a href="/wiki/Shear_strength_(soil)" title="Shear strength (soil)">Shear strength</a></li> <li><a href="/wiki/Soil_liquefaction" title="Soil liquefaction">Sensitivity</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Structures <br />(<a href="/wiki/Soil-structure_interaction" title="Soil-structure interaction">Interaction</a>)</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;">Natural features</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Topography" title="Topography">Topography</a></li> <li><a href="/wiki/Vegetation" title="Vegetation">Vegetation</a></li> <li><a href="/wiki/Terrain" title="Terrain">Terrain</a></li> <li><a href="/wiki/Topsoil" title="Topsoil">Topsoil</a></li> <li><a href="/wiki/Water_table" title="Water table">Water table</a></li> <li><a href="/wiki/Bedrock" title="Bedrock">Bedrock</a></li> <li><a href="/wiki/Subgrade" title="Subgrade">Subgrade</a></li> <li><a href="/wiki/Subsoil" title="Subsoil">Subsoil</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;"><a href="/wiki/Earthworks_(engineering)" title="Earthworks (engineering)">Earthworks</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li>Shoring structures <ul><li><a href="/wiki/Retaining_wall" title="Retaining wall">Retaining walls</a></li> <li><a href="/wiki/Gabion" title="Gabion">Gabion</a></li> <li><a href="/wiki/Ground_freezing" title="Ground freezing">Ground freezing</a></li> <li><a href="/wiki/Mechanically_stabilized_earth" title="Mechanically stabilized earth">Mechanically stabilized earth</a></li> <li><a href="/wiki/Pressure_grouting" title="Pressure grouting">Pressure grouting</a></li> <li><a href="/wiki/Slurry_wall" title="Slurry wall">Slurry wall</a></li> <li><a href="/wiki/Soil_nailing" title="Soil nailing">Soil nailing</a></li> <li><a href="/wiki/Tieback_(geotechnical)" title="Tieback (geotechnical)">Tieback</a></li></ul></li> <li><a href="/wiki/Land_development" title="Land development">Land development</a></li> <li><a href="/wiki/Landfill" title="Landfill">Landfill</a></li> <li><a href="/wiki/Digging" title="Digging">Excavation</a></li> <li><a href="/wiki/Trench" title="Trench">Trench</a></li> <li><a href="/wiki/Embankment_(earthworks)" title="Embankment (earthworks)">Embankment</a></li> <li><a href="/wiki/Cut_(earthworks)" title="Cut (earthworks)">Cut</a></li> <li><a href="/wiki/Causeway" title="Causeway">Causeway</a></li> <li><a href="/wiki/Terrace_(earthworks)" title="Terrace (earthworks)">Terracing</a></li> <li><a class="mw-selflink-fragment" href="#Cut-and-cover">Cut-and-cover</a></li> <li><a href="/wiki/Cut_and_fill" title="Cut and fill">Cut and fill</a></li> <li><a href="/wiki/Fill_dirt" title="Fill dirt">Fill dirt</a></li> <li><a href="/wiki/Grading_(engineering)" class="mw-redirect" title="Grading (engineering)">Grading</a></li> <li><a href="/wiki/Land_reclamation" title="Land reclamation">Land reclamation</a></li> <li><a href="/wiki/Track_bed" title="Track bed">Track bed</a></li> <li><a href="/wiki/Erosion_control" title="Erosion control">Erosion control</a></li> <li><a href="/wiki/Earth_structure" title="Earth structure">Earth structure</a></li> <li><a href="/wiki/Expanded_clay_aggregate" title="Expanded clay aggregate">Expanded clay aggregate</a></li> <li><a href="/wiki/Crushed_stone" title="Crushed stone">Crushed stone</a></li> <li><a href="/wiki/Geosynthetics" title="Geosynthetics">Geosynthetics</a> <ul><li><a href="/wiki/Geotextile" title="Geotextile">Geotextile</a></li> <li><a href="/wiki/Geomembrane" title="Geomembrane">Geomembrane</a></li> <li><a href="/wiki/Geosynthetic_clay_liner" title="Geosynthetic clay liner">Geosynthetic clay liner</a></li> <li><a href="/wiki/Cellular_confinement" title="Cellular confinement">Cellular confinement</a></li></ul></li> <li><a href="/wiki/Infiltration_(hydrology)" title="Infiltration (hydrology)">Infiltration</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;"><a href="/wiki/Foundation_(engineering)" title="Foundation (engineering)">Foundations</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Shallow_foundation" title="Shallow foundation">Shallow</a></li> <li><a href="/wiki/Deep_foundation" title="Deep foundation">Deep</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Soil_mechanics" title="Soil mechanics">Mechanics</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;">Forces</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Effective_stress" title="Effective stress">Effective stress</a></li> <li><a href="/wiki/Pore_water_pressure" title="Pore water pressure">Pore water pressure</a></li> <li><a href="/wiki/Lateral_earth_pressure" title="Lateral earth pressure">Lateral earth pressure</a></li> <li><a href="/wiki/Overburden_pressure" title="Overburden pressure">Overburden pressure</a></li> <li><a href="/wiki/Preconsolidation_pressure" title="Preconsolidation pressure">Preconsolidation pressure</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:10.0em;font-weight: normal;">Phenomena/<br />problems</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Permafrost" title="Permafrost">Permafrost</a></li> <li><a href="/wiki/Frost_heaving" title="Frost heaving">Frost heaving</a></li> <li><a href="/wiki/Consolidation_(soil)" class="mw-redirect" title="Consolidation (soil)">Consolidation</a></li> <li><a href="/wiki/Soil_compaction" title="Soil compaction">Compaction</a></li> <li><a href="/wiki/Earthquake" title="Earthquake">Earthquake</a> <ul><li><a href="/wiki/Response_spectrum" title="Response spectrum">Response spectrum</a></li> <li><a href="/wiki/Seismic_hazard" title="Seismic hazard">Seismic hazard</a></li> <li><a href="/wiki/S_wave" title="S wave">Shear wave</a></li></ul></li> <li><a href="/wiki/Landslide" title="Landslide">Landslide</a> analysis <ul><li><a href="/wiki/Slope_stability_analysis" title="Slope stability analysis">Stability analysis</a></li> <li><a href="/wiki/Landslide_mitigation" title="Landslide mitigation">Mitigation</a></li> <li><a href="/wiki/Landslide_classification" title="Landslide classification">Classification</a></li> <li><a href="/wiki/Sliding_criterion_(geotechnical_engineering)" title="Sliding criterion (geotechnical engineering)">Sliding criterion</a></li> <li><a href="/wiki/Road#Slab_stabilization" title="Road">Slab stabilisation</a></li></ul></li> <li><a href="/wiki/Bearing_capacity" title="Bearing capacity">Bearing capacity</a> * <a href="/wiki/Stress_distribution_in_soil" title="Stress distribution in soil">Stress distribution in soil</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Software" title="Software">Numerical analysis <br />software</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/SEEP2D" title="SEEP2D">SEEP2D</a></li> <li><a href="/w/index.php?title=STABL&action=edit&redlink=1" class="new" title="STABL (page does not exist)">STABL</a></li> <li><a href="/wiki/SVFlux" title="SVFlux">SVFlux</a></li> <li><a href="/wiki/SVSlope" title="SVSlope">SVSlope</a></li> <li><a href="/wiki/UTEXAS" title="UTEXAS">UTEXAS</a></li> <li><a href="/wiki/Plaxis" title="Plaxis">Plaxis</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Geoprofessions" title="Geoprofessions">Related fields</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Geology" title="Geology">Geology</a></li> <li><a href="/wiki/Geochemistry" title="Geochemistry">Geochemistry</a></li> <li><a href="/wiki/Petrology" title="Petrology">Petrology</a></li> <li><a href="/wiki/Earthquake_engineering" title="Earthquake engineering">Earthquake engineering</a></li> <li><a href="/wiki/Geomorphology" title="Geomorphology">Geomorphology</a></li> <li><a href="/wiki/Soil_science" title="Soil science">Soil science</a></li> <li><a href="/wiki/Hydrology" title="Hydrology">Hydrology</a></li> <li><a href="/wiki/Hydrogeology" title="Hydrogeology">Hydrogeology</a></li> <li><a href="/wiki/Biogeography" title="Biogeography">Biogeography</a></li> <li><a href="/wiki/Earth_materials" title="Earth materials">Earth materials</a></li> <li><a href="/wiki/Archaeology" title="Archaeology">Archaeology</a></li> <li><a href="/wiki/Agricultural_science" title="Agricultural science">Agricultural science</a> <ul><li><a href="/wiki/Agrology" class="mw-redirect" title="Agrology">Agrology</a></li></ul></li></ul> </div></td></tr></tbody></table></div> <style data-mw-deduplicate="TemplateStyles:r1130092004">.mw-parser-output .portal-bar{font-size:88%;font-weight:bold;display:flex;justify-content:center;align-items:baseline}.mw-parser-output .portal-bar-bordered{padding:0 2em;background-color:#fdfdfd;border:1px solid #a2a9b1;clear:both;margin:1em auto 0}.mw-parser-output .portal-bar-related{font-size:100%;justify-content:flex-start}.mw-parser-output .portal-bar-unbordered{padding:0 1.7em;margin-left:0}.mw-parser-output .portal-bar-header{margin:0 1em 0 0.5em;flex:0 0 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.navbox+link+.portal-bar,.mw-parser-output .navbox+style+.portal-bar,.mw-parser-output .navbox+link+.portal-bar-bordered,.mw-parser-output .navbox+style+.portal-bar-bordered,.mw-parser-output .sister-bar+link+.portal-bar,.mw-parser-output .sister-bar+style+.portal-bar,.mw-parser-output .portal-bar+.navbox-styles+.navbox,.mw-parser-output .portal-bar+.navbox-styles+.sister-bar{margin-top:-1px}</style><div class="portal-bar noprint metadata noviewer portal-bar-bordered" role="navigation" aria-label="Portals"><span class="portal-bar-header"><a href="/wiki/Wikipedia:Contents/Portals" title="Wikipedia:Contents/Portals">Portal</a>:</span><ul class="portal-bar-content"><li class="portal-bar-item"><span class="nowrap"><span typeof="mw:File"><a href="/wiki/File:P_parthenon.svg" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f4/P_parthenon.svg/21px-P_parthenon.svg.png" decoding="async" width="21" height="19" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f4/P_parthenon.svg/32px-P_parthenon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f4/P_parthenon.svg/42px-P_parthenon.svg.png 2x" data-file-width="400" data-file-height="360" /></a></span> </span><a href="/wiki/Portal:Architecture" title="Portal:Architecture">Architecture</a></li></ul></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"></div><div role="navigation" class="navbox" aria-labelledby="Man-made_and_man-related_subterranea" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Man-made_and_man-related_subterranea" title="Template:Man-made and man-related subterranea"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Man-made_and_man-related_subterranea" title="Template talk:Man-made and man-related subterranea"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Man-made_and_man-related_subterranea" title="Special:EditPage/Template:Man-made and man-related subterranea"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Man-made_and_man-related_subterranea" style="font-size:114%;margin:0 4em">Man-made and man-related <a href="/wiki/Subterranea_(geography)" title="Subterranea (geography)">subterranea</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Natural features</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cave" title="Cave">Cave</a></li> <li><a href="/wiki/Cenote" title="Cenote">Cenote</a></li> <li><a href="/wiki/Grotto" title="Grotto">Grotto</a></li> <li><a href="/wiki/Sinkhole" title="Sinkhole">Sinkhole</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Civilian features</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Basement" title="Basement">Basement</a></li> <li><a href="/wiki/Burial_vault_(tomb)" title="Burial vault (tomb)">Burial vault (tomb)</a></li> <li><a href="/wiki/Borehole" title="Borehole">Borehole</a></li> <li><a href="/wiki/Catacombs" title="Catacombs">Catacombs</a></li> <li><a href="/wiki/Dungeon" title="Dungeon">Dungeon</a></li> <li><a href="/wiki/Dugout_(shelter)" title="Dugout (shelter)">Dugout (shelter)</a></li> <li><a href="/wiki/Dry_well" title="Dry well">Dry well</a></li> <li><a href="/wiki/Earth_shelter" title="Earth shelter">Earth shelter</a></li> <li><a href="/wiki/Erdstall" title="Erdstall">Erdstall</a></li> <li><a href="/wiki/Fogou" title="Fogou">Fogou</a></li> <li><a href="/wiki/Hypogeum" title="Hypogeum">Hypogeum</a></li> <li><a href="/wiki/Manhole" title="Manhole">Manhole</a></li> <li><a href="/wiki/Rapid_transit" title="Rapid transit">Rapid transit</a></li> <li><a href="/wiki/Rock-cut_tomb" title="Rock-cut tomb">Rock-cut tomb</a></li> <li><a href="/wiki/Root_cellar" title="Root cellar">Root cellar</a></li> <li><a class="mw-selflink selflink">Tunnel</a></li> <li><a href="/wiki/Utility_vault" title="Utility vault">Utility vault</a></li> <li><a href="/wiki/Underground_city" title="Underground city">Underground city</a></li> <li><a href="/wiki/Well" title="Well">Well</a></li> <li><a href="/wiki/Wine_cave" title="Wine cave">Wine cave</a></li> <li><a href="/wiki/Secret_passage" title="Secret passage">Secret passage</a></li> <li><a href="/wiki/Semi-basement" title="Semi-basement">Semi-basement</a></li> <li><a href="/wiki/Stepwell" title="Stepwell">Stepwell</a></li> <li><a href="/wiki/Storm_cellar" title="Storm cellar">Storm cellar</a></li> <li><a href="/wiki/Smuggling_tunnel" title="Smuggling tunnel">Smuggling tunnel</a></li> <li><a href="/wiki/Ventilation_shaft" title="Ventilation shaft">Ventilation shaft</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Military features</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Air_raid_shelter" title="Air raid shelter">Air raid shelter</a></li> <li><a href="/wiki/Bunker" title="Bunker">Bunker</a></li> <li><a href="/wiki/Blast_shelter" title="Blast shelter">Blast shelter</a></li> <li><a href="/wiki/Casemate" title="Casemate">Casemate</a></li> <li><a href="/wiki/Fallout_shelter" title="Fallout shelter">Fallout shelter</a></li> <li><a href="/wiki/Missile_launch_facility" title="Missile launch facility">Missile launch facility</a> (silo)</li> <li><a href="/wiki/Scallywag_bunker" title="Scallywag bunker">Scallywag bunker</a></li> <li><a href="/wiki/Underground_base" title="Underground base">Underground base</a></li> <li><a href="/wiki/Underground_hangar" title="Underground hangar">Underground hangar</a></li> <li><a href="/wiki/Spider_hole" title="Spider hole">Spider hole</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Mining" title="Mining">Mining</a>, <a href="/wiki/Quarrying" class="mw-redirect" title="Quarrying">quarrying</a>, and<br /><a href="/wiki/Underground_construction" title="Underground construction">underground construction</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Rock-cut_architecture" title="Rock-cut architecture">Rock-cut architecture</a></li> <li><a href="/wiki/Subsurface_utility_engineering" title="Subsurface utility engineering">Subsurface utility engineering</a></li> <li><a href="/wiki/Tunnel_construction" title="Tunnel construction">Tunnel construction</a></li> <li><a href="/wiki/Underground_mine_ventilation" title="Underground mine ventilation">Underground mine ventilation</a></li> <li><a href="/wiki/Underground_mining_(hard_rock)" class="mw-redirect" title="Underground mining (hard rock)">Underground mining (hard rock)</a></li> <li><a href="/wiki/Underground_mining_(soft_rock)" class="mw-redirect" title="Underground mining (soft rock)">Underground mining (soft rock)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related topics</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cave_dweller" title="Cave dweller">Cave dweller</a></li> <li><a href="/wiki/Caves_of_Maastricht" title="Caves of Maastricht">Caves of Maastricht</a></li> <li><a href="/wiki/Civil_defense" title="Civil defense">Civil defense</a></li> <li><a href="/wiki/Coober_Pedy" title="Coober Pedy">Coober Pedy</a></li> <li><a href="/wiki/Houston_tunnel_system" title="Houston tunnel system">Houston tunnel system</a></li> <li><a href="/wiki/K%C5%91b%C3%A1nya_cellar_system" title="Kőbánya cellar system">Kőbánya cellar system</a></li> <li><a href="/wiki/Tunnel_warfare" title="Tunnel warfare">Tunnel warfare</a></li> <li><a href="/wiki/Tunnel_network" title="Tunnel network">Tunnel network</a></li> <li><a href="/wiki/Trench_warfare" title="Trench warfare">Trench warfare</a></li> <li><a href="/wiki/Underground_living" title="Underground living">Underground living</a></li> <li><a href="/wiki/Underground_City_(Beijing)" title="Underground City (Beijing)">Underground City (Beijing)</a></li> <li><a href="/wiki/Underground_City,_Montreal" title="Underground City, Montreal">Underground City, Montreal</a></li> <li><a href="/wiki/Mine_exploration" title="Mine exploration">Mine exploration</a></li> <li><a href="/wiki/Mines_of_Paris" title="Mines of Paris">Mines of Paris</a></li> <li><a href="/wiki/Mole_people" title="Mole people">Mole people</a></li> <li><a href="/wiki/Naples_underground_geothermal_zone" title="Naples underground geothermal zone">Naples underground geothermal zone</a></li> <li><a href="/wiki/Sapping" title="Sapping">Sapping</a></li> <li><a href="/wiki/Subterranean_London" title="Subterranean London">Subterranean London</a></li> <li><a href="/wiki/Subterranean_Toledo" title="Subterranean Toledo">Subterranean Toledo</a></li> <li><a href="/wiki/Subterranean_warfare" title="Subterranean warfare">Subterranean warfare</a></li> <li><a href="/wiki/Subterranean_fiction" title="Subterranean fiction">Subterranean fiction</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Earth shelters US</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Bill_Gates%27_house" class="mw-redirect" title="Bill Gates' house">Bill Gates' house</a></li> <li><a href="/wiki/Forestiere_Underground_Gardens" title="Forestiere Underground Gardens">Forestiere Underground Gardens</a></li> <li><a href="/wiki/Underground_House_Colorado" title="Underground House Colorado">Underground House Colorado</a></li> <li><a href="/wiki/Underground_House_Las_Vegas" title="Underground House Las Vegas">Underground House Las Vegas</a></li> <li><a href="/wiki/Underground_World_Home" title="Underground World Home">Underground World Home</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Earth shelters UK</th><td class="navbox-list-with-group 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