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/* cache key: enwiki:resourceloader:filter:minify-js:7:f01864140ec2ba42468570048b875f39 */ }</script> <script>if(window.mw){ mw.loader.load(["mediawiki.page.startup","mediawiki.legacy.wikibits","mediawiki.legacy.ajax","ext.vector.footerCleanup","ext.wikimediaShopLink.core","ext.postEdit","wikibase.client.init","ext.centralNotice.bannerController"]); }</script> <script src="//web.archive.org/web/20130424163117js_/http://bits.wikimedia.org/geoiplookup"></script><link rel="dns-prefetch" href="//web.archive.org/web/20130424163117/http://meta.wikimedia.org/"/></head> <body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-Continuous_track skin-vector action-view vector-animateLayout"> <div id="mw-page-base" class="noprint"></div> <div id="mw-head-base" class="noprint"></div>  <div id="content" class="mw-body" role="main"> <a id="top"></a> <div id="mw-js-message" style="display:none;"></div>  <div id="siteNotice"></div>   <h1 id="firstHeading" class="firstHeading" lang="en"><span dir="auto">Continuous track</span></h1>   <div id="bodyContent">  <div id="siteSub">From Wikipedia, the free encyclopedia</div>   <div id="contentSub"></div>   <div id="jump-to-nav" class="mw-jump"> Jump to: <a href="#mw-navigation">navigation</a>, <a href="#p-search">search</a> </div>   <div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><table class="metadata plainlinks ambox ambox-content ambox-Refimprove" style=""> <tr> <td class="mbox-image"> <div style="width: 52px;"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" width="50" height="39" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x"/></div> </td> <td class="mbox-text" style=""><span class="mbox-text-span">This article <b>needs additional citations for verification</b>. <span class="hide-when-compact">Please help <a class="external text" href="//web.archive.org/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit">improve this article</a> by <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Help:Introduction_to_referencing/1" title="Help:Introduction to referencing/1">adding citations to reliable sources</a>. Unsourced material may be <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Template:Citation_needed" title="Template:Citation needed">challenged</a> and <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Wikipedia:Verifiability#Burden_of_evidence" title="Wikipedia:Verifiability">removed</a>.</span> <small><i>(November 2006)</i></small> </span></td> </tr> </table> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Caterpillar_track_shingle.JPG" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Caterpillar_track_shingle.JPG/220px-Caterpillar_track_shingle.JPG" width="220" height="165" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Caterpillar_track_shingle.JPG/330px-Caterpillar_track_shingle.JPG 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Caterpillar_track_shingle.JPG/440px-Caterpillar_track_shingle.JPG 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Caterpillar_track_shingle.JPG" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> A closeup of continuous tracks on a bulldozer</div> </div> </div> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Challenger_1_suspension.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Challenger_1_suspension.jpg/220px-Challenger_1_suspension.jpg" width="220" height="142" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Challenger_1_suspension.jpg/330px-Challenger_1_suspension.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Challenger_1_suspension.jpg/440px-Challenger_1_suspension.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Challenger_1_suspension.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> A British Army Challenger 1 tank</div> </div> </div> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Tracked_tractor_-_geograph.org.uk_-_1023986.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Tracked_tractor_-_geograph.org.uk_-_1023986.jpg/220px-Tracked_tractor_-_geograph.org.uk_-_1023986.jpg" width="220" height="165" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Tracked_tractor_-_geograph.org.uk_-_1023986.jpg/330px-Tracked_tractor_-_geograph.org.uk_-_1023986.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Tracked_tractor_-_geograph.org.uk_-_1023986.jpg/440px-Tracked_tractor_-_geograph.org.uk_-_1023986.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Tracked_tractor_-_geograph.org.uk_-_1023986.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> An agricultural tractor with rubber tracks</div> </div> </div> <p><b>Continuous tracks</b>, also called <b>tank treads</b><sup id="cite_ref-stith_1-0" class="reference"><a href="#cite_note-stith-1"><span>[</span>1<span>]</span></a></sup> or <b>caterpillar tracks</b>, are a system of <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Vehicle_propulsion" title="Vehicle propulsion" class="mw-redirect">vehicle propulsion</a> in which a continuous band of treads is driven by two or more wheels. This band is typically made of modular steel plates in the case of military vehicles, or rubber reinforced with steel wires in the case of lighter agricultural or construction vehicles. The large surface area of the tracks distributes the weight of the vehicle better than steel or rubber tires on an equivalent vehicle, enabling a continuous tracked vehicle to traverse soft ground with less likelihood of becoming stuck due to sinking. The prominent treads of the metal plates are both hard-wearing and damage resistant, especially in comparison to rubber tires. The aggressive treads of the tracks provide good traction in soft surfaces but can damage paved surfaces. Special tracks that incorporate rubber pads can be installed for use on paved surfaces to prevent the damage that can be caused by all-metal tracks.</p> <p>Continuous tracks can be traced back as far as 1770 and today are commonly used on a variety of vehicles including <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Bulldozer" title="Bulldozer">bulldozers</a>, <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Excavator" title="Excavator">excavators</a>, <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Tank" title="Tank">tanks</a>, and <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Tractor" title="Tractor">tractors</a>, but can be found on any vehicle used in an application that can benefit from the added traction, low ground pressure and durability inherent in continuous track propulsion systems.</p> <table id="toc" class="toc"> <tr> <td> <div id="toctitle"> <h2>Contents</h2> </div> <ul> <li class="toclevel-1 tocsection-1"><a href="#History"><span class="tocnumber">1</span> <span class="toctext">History</span></a></li> <li class="toclevel-1 tocsection-2"><a href="#Engineering"><span class="tocnumber">2</span> <span class="toctext">Engineering</span></a> <ul> <li class="toclevel-2 tocsection-3"><a href="#Construction_and_Operation"><span class="tocnumber">2.1</span> <span class="toctext">Construction and Operation</span></a> <ul> <li class="toclevel-3 tocsection-4"><a href="#Overlapping_road_wheels"><span class="tocnumber">2.1.1</span> <span class="toctext">Overlapping road wheels</span></a></li> </ul> </li> <li class="toclevel-2 tocsection-5"><a href="#Advantages"><span class="tocnumber">2.2</span> <span class="toctext">Advantages</span></a></li> <li class="toclevel-2 tocsection-6"><a href="#Disadvantages"><span class="tocnumber">2.3</span> <span class="toctext">Disadvantages</span></a></li> <li class="toclevel-2 tocsection-7"><a href="#Non-metal_tread_patterns"><span class="tocnumber">2.4</span> <span class="toctext">Non-metal tread patterns</span></a> <ul> <li class="toclevel-3 tocsection-8"><a href="#Aggressive_Tread_Pattern"><span class="tocnumber">2.4.1</span> <span class="toctext">Aggressive Tread Pattern</span></a></li> <li class="toclevel-3 tocsection-9"><a href="#Anti-Vibration_Tread_Pattern"><span class="tocnumber">2.4.2</span> <span class="toctext">Anti-Vibration Tread Pattern</span></a></li> </ul> </li> <li class="toclevel-2 tocsection-10"><a href="#.22Live.22_and_.22Dead.22_track"><span class="tocnumber">2.5</span> <span class="toctext">"Live" and "Dead" track</span></a></li> </ul> </li> <li class="toclevel-1 tocsection-11"><a href="#See_also"><span class="tocnumber">3</span> <span class="toctext">See also</span></a></li> <li class="toclevel-1 tocsection-12"><a href="#References"><span class="tocnumber">4</span> <span class="toctext">References</span></a></li> <li class="toclevel-1 tocsection-13"><a href="#External_links"><span class="tocnumber">5</span> <span class="toctext">External links</span></a></li> </ul> </td> </tr> </table> <h2><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=1" title="Edit section: History">edit</a>]</span> <span class="mw-headline" id="History">History</span></h2> <div class="thumb tleft"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Lombard_steam_log_hauler.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Lombard_steam_log_hauler.jpg/220px-Lombard_steam_log_hauler.jpg" width="220" height="146" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Lombard_steam_log_hauler.jpg/330px-Lombard_steam_log_hauler.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Lombard_steam_log_hauler.jpg/440px-Lombard_steam_log_hauler.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Lombard_steam_log_hauler.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> Lombard Steam Log Hauler (Designed, patented 1901)</div> </div> </div> <div class="thumb tleft"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Roberts_tracked_steam_tractor.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Roberts_tracked_steam_tractor.jpg/220px-Roberts_tracked_steam_tractor.jpg" width="220" height="153" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Roberts_tracked_steam_tractor.jpg/330px-Roberts_tracked_steam_tractor.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Roberts_tracked_steam_tractor.jpg/440px-Roberts_tracked_steam_tractor.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Roberts_tracked_steam_tractor.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> <a href="/web/20130424163117/http://en.wikipedia.org/wiki/David_Roberts_(engineer)" title="David Roberts (engineer)">David Roberts</a> tracked steam tractor c.1908</div> </div> </div> <div class="thumb tleft"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Hornsby.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Hornsby.jpg/220px-Hornsby.jpg" width="220" height="147" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Hornsby.jpg/330px-Hornsby.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Hornsby.jpg/440px-Hornsby.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Hornsby.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> Hornsby tractor, 1909</div> </div> </div> <p>Perhaps the oldest implementation of something resembling continuous tracks is to be found in theories of <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Prehistory" title="Prehistory">prehistoric</a> erection of large stone monuments, when <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Megalith" title="Megalith">megaliths</a> may have been slid atop rounded wooden logs. The logs were grooved near their ends to be held in alignment and rotation by belts out past the edge of the megalith and lubricated by some means, probably organic. The logs are carried from the back of the procession to the front in an endless chain, like continuous track. The system is a precursor to development of the axle, which keeps a rotating cylinder fixed relative to its cargo.</p> <p>In modern times, continuous track propulsion systems can be traced back to a crude continuous track system designed in the 1770s by <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Richard_Lovell_Edgeworth" title="Richard Lovell Edgeworth">Richard Lovell Edgeworth</a>. Polish mathematician and inventor <a href="/web/20130424163117/http://en.wikipedia.org/wiki/J%C3%B3zef_Maria_Hoene-Wro%C5%84ski" title="Józef Maria Hoene-Wroński">Józef Maria Hoene-Wroński</a> conceived of the idea in the 1830s.<sup id="cite_ref-wronski_2-0" class="reference"><a href="#cite_note-wronski-2"><span>[</span>2<span>]</span></a></sup> The British <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Polymath" title="Polymath">polymath</a> Sir <a href="/web/20130424163117/http://en.wikipedia.org/wiki/George_Cayley" title="George Cayley">George Cayley</a> patented a continuous track, which he called a "universal railway".<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span>[</span>3<span>]</span></a></sup> In 1837, a <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Russia" title="Russia">Russian</a> inventor <a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Dmitry_Zagryazhsky&action=edit&redlink=1" class="new" title="Dmitry Zagryazhsky (page does not exist)">Dmitry Zagryazhsky</a> designed a "carriage with mobile tracks" which he patented the same year, but due to a lack of funds he was unable to build a working prototype, and his patent was voided in 1839. <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Traction_engine" title="Traction engine">Steam powered tractors</a> using a form of continuous track were reported in use with the Western Alliance during the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Crimean_War" title="Crimean War">Crimean War</a> in the 1850s.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span>[</span>4<span>]</span></a></sup> A <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Dreadnaught_Wheel" title="Dreadnaught Wheel">Dreadnaught Wheel</a> or "endless railway wheel" had been patented by the British engineer <a href="/web/20130424163117/http://en.wikipedia.org/wiki/James_Boydell" title="James Boydell">James Boydell</a> 1846.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span>[</span>5<span>]</span></a></sup></p> <p>In 1877, a Russian, <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Fyodor_Blinov" title="Fyodor Blinov">Fyodor Blinov</a>, created a tracked vehicle called "<a href="/web/20130424163117/http://en.wikipedia.org/wiki/Wagon" title="Wagon">wagon</a> moved on endless rails" (caterpillars).<sup id="cite_ref-blinov_6-0" class="reference"><a href="#cite_note-blinov-6"><span>[</span>6<span>]</span></a></sup> It lacked self-propulsion and was pulled by horses. Blinov received a patent for his "wagon" in 1878. From 1881 to 1888 he developed a steam-powered caterpillar-tractor. This self-propelled crawler was successfully tested and featured at a farmers' exhibition in 1896.<sup id="cite_ref-blinov_6-1" class="reference"><a href="#cite_note-blinov-6"><span>[</span>6<span>]</span></a></sup></p> <p>A little known American inventor, Henery T. Stith, developed a continuous track prototype which was, in multiple forms, patented in 1873, 1880, and 1900. The last was for the application of the track to a prototype off-road bicycle built for his son.<sup id="cite_ref-stith_1-1" class="reference"><a href="#cite_note-stith-1"><span>[</span>1<span>]</span></a></sup> The 1900 prototype is retained by his surviving family.</p> <p>An effective continuous track was invented and implemented by <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Alvin_Orlando_Lombard" title="Alvin Orlando Lombard">Alvin Orlando Lombard</a> for the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Lombard_Steam_Log_Hauler" title="Lombard Steam Log Hauler">Lombard Steam Log Hauler</a>. He was granted a patent in 1901 and built the first steam-powered log hauler at the Waterville Iron Works in Waterville, Maine, the same year. In all, 83 Lombard steam log haulers are known to have been built up to 1917, when production switched entirely to internal combustion engine powered machines, ending with a Fairbanks diesel powered unit in 1934. Undoubtedly, Alvin Lombard was the first commercial manufacturer of the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Tractor_crawler" title="Tractor crawler" class="mw-redirect">tractor crawler</a>. At least one of Lombard's steam-powered machines apparently remains in working order.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span>[</span>7<span>]</span></a></sup> A gasoline-powered Lombard hauler is on display at the Maine State Museum in Augusta.</p> <p>In addition, there may have been up to twice as many Phoenix Centipeed versions of the steam log hauler built under license from Lombard, with vertical instead of horizontal cylinders. In 1903, the founder of Holt Manufacturing, <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Benjamin_Holt" title="Benjamin Holt">Benjamin Holt</a>, paid Lombard $60,000 for the right to produce vehicles under his patent. There seems to have been an agreement made after Lombard moved to California, but when previous track patents were studied, discrepancies arose concerning how this matter was resolved.</p> <p>At about the same time a British agricultural company, <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Richard_Hornsby_%26_Sons" title="Richard Hornsby & Sons">Hornsby</a> in <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Grantham" title="Grantham">Grantham</a>, developed a continuous track which was patented in 1905.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span>[</span>8<span>]</span></a></sup> The design differed from modern tracks in that it flexed in only one direction, with the effect that the links locked together to form a solid rail on which the road wheels ran. Hornsby's tracked vehicles were given trials as <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Artillery_tractor" title="Artillery tractor">artillery tractors</a> by the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/British_Army" title="British Army">British Army</a> on several occasions between 1905 and 1910, but not adopted. The patent was purchased by Holt. The Hornsby tractors featured a track-steer clutch arrangement, which is the basis of the modern crawler operation, and some say an observing British soldier quipped that it crawled like a caterpillar. The word was shrewdly <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Trademark" title="Trademark">trademarked</a> and defended by Holt.</p> <p>American <a href="/web/20130424163117/http://en.wikipedia.org/wiki/James_B._Hill" title="James B. Hill">James B. Hill</a>, working in Bowling Green, Wood County, Ohio, patented what he termed "apron traction"<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span>[</span>9<span>]</span></a></sup> on September 24, 1907.</p> <div class="thumb tleft"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:CatD9T.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/CatD9T.jpg/220px-CatD9T.jpg" width="220" height="146" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/CatD9T.jpg/330px-CatD9T.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/CatD9T.jpg/440px-CatD9T.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:CatD9T.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> A modern <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Caterpillar_Inc." title="Caterpillar Inc.">Caterpillar Inc.</a> D9T bulldozer</div> </div> </div> <p><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Caterpillar_Tractor_Company" title="Caterpillar Tractor Company" class="mw-redirect">Caterpillar Tractor Company</a> began in 1925 from a merger of the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Holt_Manufacturing_Company" title="Holt Manufacturing Company">Holt Manufacturing Company</a> and the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/C._L._Best" title="C. L. Best">C. L. Best Tractor Company</a>; an early successful manufacturer of crawler tractors. Caterpillar brand continuous tracks have since revolutionized construction vehicles and <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Land_warfare" title="Land warfare" class="mw-redirect">land warfare</a>. Track systems have been developed and improved during their use on fighting vehicles. During <a href="/web/20130424163117/http://en.wikipedia.org/wiki/World_War_I" title="World War I">World War I</a> Holt tractors were used by the British and Austro-Hungarian armies to tow heavy artillery and stimulated the development of tanks in several countries. The first tanks to go into action, built by Great Britain, were designed from scratch and were inspired by but not directly based on the Holt. The slightly later French and German tanks were built on modified Holt running gear.</p> <p>A <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Concept_vehicle" title="Concept vehicle" class="mw-redirect">concept vehicle</a> called the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Hyanide" title="Hyanide">Hyanide</a> proposes a continuous track drive motorcycle. It involves a steerable continuous track to enable the vehicle to corner.<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span>[</span>10<span>]</span></a></sup></p> <p>The Canadian company BPG Werks has developed a dual tracked recreational vehicle called the DTV Shredder. This gas-powered vehicle consists of two caterpillar tracks steered by activating a dual <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Continuously_variable_transmission" title="Continuously variable transmission">CVT</a> connected to the rider deck. As the rider leans the deck side to side, the speed of the tracks change allowing for <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Differential_steering" title="Differential steering" class="mw-redirect">differential steering</a>.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span>[</span>11<span>]</span></a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span>[</span>12<span>]</span></a></sup></p> <p><br style="clear:both;"/></p> <h2><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=2" title="Edit section: Engineering">edit</a>]</span> <span class="mw-headline" id="Engineering">Engineering</span></h2> <h3><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=3" title="Edit section: Construction and Operation">edit</a>]</span> <span class="mw-headline" id="Construction_and_Operation">Construction and Operation</span></h3> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Tracks_(diagram).png" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Tracks_%28diagram%29.png/220px-Tracks_%28diagram%29.png" width="220" height="86" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Tracks_%28diagram%29.png/330px-Tracks_%28diagram%29.png 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Tracks_%28diagram%29.png/440px-Tracks_%28diagram%29.png 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Tracks_(diagram).png" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> Diagram of tracked suspension.(1=rear drive wheel (rear wheel drive), 2=track, 3=return rollers, 4=front drive wheel (front wheel drive), 5=road wheels, 6=idler)</div> </div> </div> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Leclerc_p1040882.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Leclerc_p1040882.jpg/220px-Leclerc_p1040882.jpg" width="220" height="165" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Leclerc_p1040882.jpg/330px-Leclerc_p1040882.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/1/11/Leclerc_p1040882.jpg/440px-Leclerc_p1040882.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Leclerc_p1040882.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> A <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Sprocket" title="Sprocket">sprocket</a> wheel on a tank</div> </div> </div> <p>Modern tracks are built from modular chain links which together compose a closed chain. The links are jointed by a hinge, which allows the track to be flexible and wrap around a set of wheels to make an endless loop. The chain links are often broad, and made of manganese alloy steel for high strength, hardness, and abrasion resistance.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span>[</span>13<span>]</span></a></sup></p> <p>Track construction and assembly is dictated by the application. Military vehicles use a track shoe that is integral to the structure of the chain in order to reduce track weight. Reduced weight allows the vehicle to move faster and decreases overall vehicle weight to ease transportation. Since track weight is completely <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Unsprung_mass" title="Unsprung mass">unsprung</a>, reducing it improves suspension performance at speeds where the track's momentum is significant. In contrast, agricultural and construction vehicles opt for a track with shoes that attach to the chain with bolts and do not form part of the chain's structure. This allows track shoes to break without compromising the ability of the vehicle to move and decrease productivity but increases the overall weight of the track and vehicle. Extra weight is an advantage when optimizing for traction and power over speed and mobility.<sup class="noprint Inline-Template" style="white-space:nowrap;">[<i><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Wikipedia:Disputed_statement" title="Wikipedia:Disputed statement" class="mw-redirect"><span title="The material near this tag may not be factual or accurate. (February 2013)">dubious</span></a> <span class="metadata">– <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Talk:Continuous_track#Dubious" title="Talk:Continuous track">discuss</a></span></i>]</sup></p> <p>The vehicle's weight is transferred to the bottom length of track by a number of road wheels, or sets of wheels called <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Bogie" title="Bogie">bogies</a>. Road wheels are typically mounted on some form of suspension to cushion the ride over rough ground. Suspension design in military vehicles is a major area of development; the very early designs were often completely unsprung. Later-developed road wheel suspension offered only a few inches of travel using springs, whereas modern hydro-pneumatic systems allow several feet of travel and include <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Shock_absorber" title="Shock absorber">shock absorbers</a>. <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Torsion-bar_suspension" title="Torsion-bar suspension" class="mw-redirect">Torsion-bar suspension</a> has become the most common type of military vehicle suspension. Construction vehicles have smaller road wheels that are designed primarily to prevent track derailment and they are normally contained in a single bogie that includes the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Idler-wheel" title="Idler-wheel">Idler-wheel</a> and sometimes the sprocket.</p> <p>Transfer of power to the track is accomplished by a <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Drive_wheel" title="Drive wheel">drive wheel</a>, or <i>drive <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Sprocket" title="Sprocket">sprocket</a></i>, driven by the motor and engaging with holes in the track links or with pegs on them to drive the track. In military vehicles, the drive wheel is typically mounted well above the contact area on the ground, allowing it to be fixed in position. In agricultural crawlers it is normally incorporated as part of the bogie. Placing suspension on the sprocket is possible, but is mechanically more complicated. A non-powered wheel, an <i>idler</i>, is placed at the opposite end of the track, primarily to tension the track, since loose track could be easily thrown (slipped) off the wheels. To prevent throwing, the inner surface of the track links usually have vertical guide horns engaging grooves, or gaps between the doubled road and idler/sprocket wheels. In military vehicles with a rear sprocket, the idler wheel is placed higher than the road wheels to allow it to climb over obstacles. Some track arrangements use return rollers to keep the top of the track running straight between the drive sprocket and idler. Others, called <i>slack track</i>, allow the track to droop and run along the tops of large road wheels. This was a feature of the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Christie_suspension" title="Christie suspension">Christie suspension</a>, leading to occasional misidentification of other slack track-equipped vehicles.</p> <h4><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=4" title="Edit section: Overlapping road wheels">edit</a>]</span> <span class="mw-headline" id="Overlapping_road_wheels">Overlapping road wheels</span></h4> <div class="thumb tleft"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Bundesarchiv_Bild_101I-635-3965-28,_Panzerfabrik_in_Deutschland.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Bundesarchiv_Bild_101I-635-3965-28%2C_Panzerfabrik_in_Deutschland.jpg/220px-Bundesarchiv_Bild_101I-635-3965-28%2C_Panzerfabrik_in_Deutschland.jpg" width="220" height="140" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Bundesarchiv_Bild_101I-635-3965-28%2C_Panzerfabrik_in_Deutschland.jpg/330px-Bundesarchiv_Bild_101I-635-3965-28%2C_Panzerfabrik_in_Deutschland.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Bundesarchiv_Bild_101I-635-3965-28%2C_Panzerfabrik_in_Deutschland.jpg/440px-Bundesarchiv_Bild_101I-635-3965-28%2C_Panzerfabrik_in_Deutschland.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Bundesarchiv_Bild_101I-635-3965-28,_Panzerfabrik_in_Deutschland.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> Overlapped and interleaved road wheels of a German <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Tiger_I" title="Tiger I">Tiger I</a> heavy tank</div> </div> </div> <p>Many World War II German military vehicles, including all vehicles originally designed to be half-tracks and all later tank designs (after the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Panzer_IV" title="Panzer IV">Panzer IV</a>), had slack-track systems, usually driven by a front-located drive sprocket, the track returning along the tops of overlapping and sometimes interleaved large diameter road wheels, as on the suspension systems of the <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Tiger_I" title="Tiger I">Tiger I</a> and <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Panther_tank" title="Panther tank">Panther</a> tanks. There were suspensions with one (sometimes double) wheel per axle, alternately supporting the inner and outer side of the track, and interleaved suspensions with two or three road wheels per axle, distributing the load over the track. <sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span>[</span>14<span>]</span></a></sup> The choice of overlapping/interleaved road wheels allowed the use of slightly more <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Torsion_bar" title="Torsion bar" class="mw-redirect">torsion bar</a> suspension members, allowing any German tracked military vehicle with such a setup to have a noticeably smoother ride over challenging terrain, leading to reduced wear and more accurate fire. As a tracked vehicle moves, the load of each wheel moves over the track, pushing down and forward that part of the earth, snow, etc. under it, similarly to a wheeled vehicle but to a lesser extent because the tread helps distribute the load. Apparently, on some surfaces, this consumes enough energy to slow the vehicle down significantly, so overlapped and interleaved wheels improve performance (including fuel consumption) by loading the track more evenly. It also must have extended the life of the tracks and possibly of the wheels. The wheels also better protect the vehicle from enemy fire, and mobility when some wheels are missing is improved. But this complicated approach has not been used since that war ended. This may be related more to maintenance than to original cost. Mud and ice collect between the overlapping areas of the road wheels, freezing solid in cold weather conditions, often immobilizing so equipped vehicles. The torsion bars and bearings may stay dry and clean, but the wheels and tread work in mud, sand, rocks, snow and so on. In addition, the outer wheels (up to 9 of them, some double) need to be removed to access the inner ones. In WW II, vehicles typically had to be maintained a few months before being destroyed or captured, but in peace time vehicles must train several crews, over a period of decades.</p> <h3><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=5" title="Edit section: Advantages">edit</a>]</span> <span class="mw-headline" id="Advantages">Advantages</span></h3> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg/220px-%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg" width="220" height="147" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg/330px-%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/d/dc/%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg/440px-%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:%D0%93%D0%A2-%D0%A1%D0%9C_at_Vankorskoe_oilfield.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> A Russian tracked vehicle designed to operate on snow</div> </div> </div> <p>Tracked vehicles have better mobility than pneumatic tyres over rough terrain. They smooth out the bumps, glide over small obstacles and are capable of crossing trenches or breaks in the terrain. Riding in a fast tracked vehicle feels like riding in a boat over heavy swells. Tracks are tougher than tyres since they cannot be punctured or torn. Tracks are much less likely to get stuck in soft ground, mud, or snow since they distribute the weight of the vehicle over a larger contact area, decreasing its <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Ground_pressure" title="Ground pressure">ground pressure</a>. In addition, the larger contact area, coupled with the cleats, or <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Grouser" title="Grouser">grousers</a>, on the track shoes, allows vastly superior traction that results in a much better ability to push or pull large loads where wheeled vehicles would dig in. <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Bulldozer" title="Bulldozer">Bulldozers</a>, which are most often tracked, use this attribute to rescue other vehicles, (such as <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Wheel_loader" title="Wheel loader" class="mw-redirect">wheel loaders</a>) which have become stuck in, or sunk into, the ground. Tracks can also give higher maneuverability, as some tracked vehicle can turn in place without forward or backward movement by driving the tracks in opposite directions. In addition, should a track be broken, assuming the correct tools are available, it can be repaired without the need for special facilities; something which is crucial in a combat situation.</p> <p>The seventy-ton <a href="/web/20130424163117/http://en.wikipedia.org/wiki/M1_Abrams" title="M1 Abrams">M1 Abrams</a> tank has an average ground pressure of just over 15 <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pounds_per_square_inch" title="Pounds per square inch">psi</a> (100 <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pascal_(unit)" title="Pascal (unit)">kPa</a>). Since tire air pressure is approximately equal to average ground pressure, a typical car will have an average ground pressure of 28 <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pounds_per_square_inch" title="Pounds per square inch">psi</a> (190 <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pascal_(unit)" title="Pascal (unit)">kPa</a>) to 33 <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pounds_per_square_inch" title="Pounds per square inch">psi</a> (230 <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pascal_(unit)" title="Pascal (unit)">kPa</a>).</p> <h3><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=6" title="Edit section: Disadvantages">edit</a>]</span> <span class="mw-headline" id="Disadvantages">Disadvantages</span></h3> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Armored_vehicle_on_trailer_p1040729.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Armored_vehicle_on_trailer_p1040729.jpg/220px-Armored_vehicle_on_trailer_p1040729.jpg" width="220" height="100" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Armored_vehicle_on_trailer_p1040729.jpg/330px-Armored_vehicle_on_trailer_p1040729.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/b/bd/Armored_vehicle_on_trailer_p1040729.jpg/440px-Armored_vehicle_on_trailer_p1040729.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Armored_vehicle_on_trailer_p1040729.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> Tracked vehicles may be put on semitrailers or railway cars for long-distance hauling.</div> </div> </div> <div class="thumb tright"> <div class="thumbinner" style="width:222px;"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Caterpillar_Tracks_On_Seal_Machine.jpg" class="image"><img alt="" src="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Caterpillar_Tracks_On_Seal_Machine.jpg/220px-Caterpillar_Tracks_On_Seal_Machine.jpg" width="220" height="165" class="thumbimage" srcset="//web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Caterpillar_Tracks_On_Seal_Machine.jpg/330px-Caterpillar_Tracks_On_Seal_Machine.jpg 1.5x, //web.archive.org/web/20130424163117im_/http://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Caterpillar_Tracks_On_Seal_Machine.jpg/440px-Caterpillar_Tracks_On_Seal_Machine.jpg 2x"/></a> <div class="thumbcaption"> <div class="magnify"><a href="/web/20130424163117/http://en.wikipedia.org/wiki/File:Caterpillar_Tracks_On_Seal_Machine.jpg" class="internal" title="Enlarge"><img src="//web.archive.org/web/20130424163117im_/http://bits.wikimedia.org/static-1.22wmf1/skins/common/images/magnify-clip.png" width="15" height="11" alt=""/></a></div> Small tracks on a roadworks machine, note the rubber pads to reduce wear on the carriageway.</div> </div> </div> <p>The disadvantages of tracks are lower top speed, much greater mechanical complexity, shorter life and the damage that their all-steel versions cause to what passes beneath them. They are perceived/misconceived to severely damage hard terrain like asphalt pavement, but, actually, often have significantly lower ground pressures than equivalent or lighter wheeled vehicles. However, they often cause damage to less firm terrain such as lawns, gravel roads, and farm fields, as the sharp edges of the track easily rout the turf. Accordingly, vehicle laws and local ordinaces often require rubberised tracks or track pads. A compromise between all-steel and all-rubber tracks exists: attaching rubber pads to individual track links ensures that continuous track vehicles can travel more smoothly, quickly, and quietly on paved surfaces. While these pads slightly reduce a vehicle's cross-country traction, in theory they prevent damage to any pavement.</p> <p>Additionally, the loss of a single segment in a track immobilizes the entire vehicle, which can be a disadvantage in situations where high reliability is important. Tracks can also ride off their guide wheels, idlers or sprockets, which can cause them to jam in an overly tight position or to come completely off the guide system (this is called a 'thrown' track). Jammed tracks may become so tight that the track may need to be broken before a repair is possible, which requires either explosives or special tools. Multi-wheeled vehicles, for example, <a href="/web/20130424163117/http://en.wikipedia.org/wiki/8_X_8" title="8 X 8" class="mw-redirect">8 X 8</a> military vehicles, may often continue driving even after the loss of one or more non-sequential wheels, depending on the base wheel pattern and drive train.</p> <p>Many manufacturers provide rubber tracks instead of steel, especially for agricultural applications. Rather than a track made of linked steel plates, a reinforced rubber belt with chevron treads is used. In comparison to steel tracks, rubber tracks are lighter, make less noise, create less maximal <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Ground_pressure" title="Ground pressure">ground pressure</a> and do not damage paved roads. The disadvantage is that they are not as solid as steel tracks. Previous belt-like systems, such as those used for <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Half-track" title="Half-track">half-tracks</a> in World War II, were not as strong, and during military actions were easily damaged. The first rubber track was invented and constructed by <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Adolphe_K%C3%A9gresse" title="Adolphe Kégresse">Adolphe Kégresse</a> and patented in 1913; rubber tracks are often called <a href="/web/20130424163117/http://en.wikipedia.org/wiki/K%C3%A9gresse_track" title="Kégresse track">Kégresse tracks</a>.</p> <p>Prolonged use places enormous strain on the drive <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Transmission_(mechanics)" title="Transmission (mechanics)">transmission</a> and the mechanics of the tracks, which must be overhauled or replaced regularly. It is common to see tracked vehicles such as bulldozers or tanks transported long distances by a wheeled carrier such as a <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Tank_transporter" title="Tank transporter">tank transporter</a> or <a href="/web/20130424163117/http://en.wikipedia.org/wiki/Train" title="Train">train</a>, though technological advances have made this practice less common among tracked military vehicles than it once was.</p> <h3><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=7" title="Edit section: Non-metal tread patterns">edit</a>]</span> <span class="mw-headline" id="Non-metal_tread_patterns">Non-metal tread patterns</span></h3> <p>There are different varieties of non-metal core tracks that are designed for very different applications.</p> <h4><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=8" title="Edit section: Aggressive Tread Pattern">edit</a>]</span> <span class="mw-headline" id="Aggressive_Tread_Pattern">Aggressive Tread Pattern</span></h4> <p>Aggressive tread NMC tracks have a more traditional lug style. They produce more pushing power & more tractive effort than their anti-vibration counterpart. Pros: -Greatly improves traction in loose ground or wet, muddy or otherwise challenging terrain. -Designed to be rugged enough to handle asphalt and other tough debris on job sites. Cons: -Increased tractive power means that these have a higher level of ground disturbance than anti-vibration NMC tracks. -The operator will experience greater vibration in the machine. Bottom Line: This track type is best suited for work sites that have a lot of loose debris or material on the ground. This rugged track pattern also is well suited to lend much needed tractive support in muddy or unstable terrain.</p> <h4><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=9" title="Edit section: Anti-Vibration Tread Pattern">edit</a>]</span> <span class="mw-headline" id="Anti-Vibration_Tread_Pattern">Anti-Vibration Tread Pattern</span></h4> <p>The anti-vibration track is generally what is on your machine as the OEM component. This track has lower ground pressure than the Aggressive tread NMC tracks. Pros: -Allows machine to tread lighter, achieving less ground disturbance. -Very comfortable, vibration reduced ride for operator. Cons: -Less pushing power in the machine in comparison to the aggressive pattern NMC tracks. Bottom Line: This track type is best designed for applications such as landscaping work. You’ll have less rework and repair because of the reduced ground disturbance from this track type. Anti-vibration tracks are best suited for turf or other compact terrain that is mostly free of debris or loose materials. <sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span>[</span>15<span>]</span></a></sup></p> <h3><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=10" title="Edit section: "Live" and "Dead" track">edit</a>]</span> <span class="mw-headline" id=".22Live.22_and_.22Dead.22_track">"Live" and "Dead" track</span></h3> <p>Tracks may be broadly categorized as "live" or "dead" track. "Dead" track is a simple design in which each track plate is connected to the rest with hinge-type pins. These dead tracks will lie flat if placed on the ground; the drive sprocket pulls the track around the wheels with no assistance from the track itself. "Live" track is slightly more complex, with each link connected to the next by a bushing which causes the track to bend slightly inward. A length of live track left on the ground will curl upward slightly at each end. Although the drive sprocket must still pull the track around the wheels, the track itself tends to bend inward, slightly assisting the sprocket and somewhat conforming to the wheels.</p> <h2><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=11" title="Edit section: See also">edit</a>]</span> <span class="mw-headline" id="See_also">See also</span></h2> <ul> <li><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Excavator" title="Excavator">Excavator</a></li> <li><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Snowcat" title="Snowcat">Snowcat</a></li> <li><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Snowmobile" title="Snowmobile">Snowmobile</a></li> <li><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Screw-propelled_vehicle" title="Screw-propelled vehicle">Screw-propelled vehicle</a></li> <li><a href="/web/20130424163117/http://en.wikipedia.org/wiki/Pedrail_wheel" title="Pedrail wheel">Pedrail wheel</a></li> </ul> <h2><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=12" title="Edit section: References">edit</a>]</span> <span class="mw-headline" id="References">References</span></h2> <div class="reflist" style="list-style-type: decimal;"> <ol class="references"> <li id="cite_note-stith-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-stith_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-stith_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><span class="citation journal"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://books.google.com/books?id=mCYDAAAAMBAJ&pg=PA63">"The Tank Tread Was His Baby"</a>. <i>Popular Science</i> (June): 63. 1944<span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft.pages=63&rft_id=http%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DmCYDAAAAMBAJ%26pg%3DPA63&rft.atitle=The+Tank+Tread+Was+His+Baby&rft.genre=book&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.date=1944&rft.jtitle=Popular+Science&rft.issue=June&rft.btitle=The+Tank+Tread+Was+His+Baby&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></span></span></li> <li id="cite_note-wronski-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-wronski_2-0">^</a></b></span> <span class="reference-text"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www-history.mcs.st-andrews.ac.uk/Biographies/Wronski.html">"Josef-Maria Hoëné de Wronski"</a><span class="reference-accessdate">. Retrieved 2009-05-30</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww-history.mcs.st-andrews.ac.uk%2FBiographies%2FWronski.html&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Josef-Maria+Ho%C3%ABn%C3%A9+de+Wronski&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></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"><span class="citation journal"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://books.google.com/books?id=_roAAAAAMAAJ&pg=PA225">"Sir George Cayley's patent universal railway"</a>. <i>Mechanics Magazine</i> <b>5</b> (127): 225–227. 1826-01-28.</span><span title="ctx_ver=Z39.88-2004&rft.volume=5&rft_id=http%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3D_roAAAAAMAAJ%26pg%3DPA225&rft.atitle=Sir+George+Cayley%27s+patent+universal+railway&rft.genre=book&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.date=1826-01-28&rft.pages=225%E2%80%93227&rft.jtitle=Mechanics+Magazine&rft.issue=127&rft.btitle=Sir+George+Cayley%27s+patent+universal+railway&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></span></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"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.firstworldwar.com/weaponry/tanks.htm">"Weapons of War - Tanks"</a><span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww.firstworldwar.com%2Fweaponry%2Ftanks.htm&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Weapons+of+War+-+Tanks&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></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"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.aonx97.dsl.pipex.com/TE-page/Town/thetford.htm">"History of Charles Burrell & Sons, including pictures of the "endless railway wheel""</a><span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww.aonx97.dsl.pipex.com%2FTE-page%2FTown%2Fthetford.htm&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=History+of+Charles+Burrell+%26+Sons%2C+including+pictures+of+the+%22endless+railway+wheel%22&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></span></span></li> <li id="cite_note-blinov-6"><span class="mw-cite-backlink">^ <a href="#cite_ref-blinov_6-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-blinov_6-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://ricolor.org/history/eng/prm/blinov/">"The inventor of the tractor"</a> (in Russian)<span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fricolor.org%2Fhistory%2Feng%2Fprm%2Fblinov%2F&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+inventor+of+the+tractor&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></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"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.allroutes.to/modeltandlombard/">"Lombard Log Hauler and Model T Snowmobile Show Route 175 Thornton, NH"</a><span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww.allroutes.to%2Fmodeltandlombard%2F&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Lombard+Log+Hauler+and+Model+T+Snowmobile+Show+Route+175+Thornton%2C+NH&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></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">British Patent No. 16,345 (1904)</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"><span><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.google.com/patents?vid=866647">U.S. Patent 0,866,647</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"><span class="citation journal">Dawn Stove (1 Aug 2006). <a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.popsci.com/popsci/whatsnew/5fa21e6759a4c010vgnvcm1000004eecbccdrcrd.html">"Your very own personal tank"</a>. <i>Popular Science</i><span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft.aulast=Dawn+Stove&rft.atitle=Your+very+own+personal+tank&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.btitle=Your+very+own+personal+tank&rft_id=http%3A%2F%2Fwww.popsci.com%2Fpopsci%2Fwhatsnew%2F5fa21e6759a4c010vgnvcm1000004eecbccdrcrd.html&rft.jtitle=Popular+Science&rft.genre=book&rft.date=1+Aug+2006&rft.au=Dawn+Stove&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></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"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.geek.com/articles/news/dtv-shredder-an-all-terrain-powered-skateboard-for-the-military-20100913/">"DTV Shredder: an all-terrain powered skateboard for the military"</a><span class="reference-accessdate">. Retrieved 3 December 2011</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww.geek.com%2Farticles%2Fnews%2Fdtv-shredder-an-all-terrain-powered-skateboard-for-the-military-20100913%2F&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=DTV+Shredder%3A+an+all-terrain+powered+skateboard+for+the+military&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></span></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"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.gizmag.com/dtv-shredder-tracked-vehicle/16668/">"DTV Shredder stands up for off-roading"</a><span class="reference-accessdate">. Retrieved 3 December 2011</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww.gizmag.com%2Fdtv-shredder-tracked-vehicle%2F16668%2F&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=DTV+Shredder+stands+up+for+off-roading&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></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"><span class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/http://www.keytometals.com/page.aspx?ID=CheckArticle&site=kts&NM=69">"Austenitic Manganese Steels"</a><span class="reference-accessdate">. Retrieved 2011-08-24</span>.</span><span title="ctx_ver=Z39.88-2004&rft_id=http%3A%2F%2Fwww.keytometals.com%2Fpage.aspx%3FID%3DCheckArticle%26site%3Dkts%26NM%3D69&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Austenitic+Manganese+Steels&rfr_id=info:sid/en.wikipedia.org:Continuous track" class="Z3988"><span style="display:none;"> </span></span></span></li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text">Peter Chamberlain and Hilary Doyle ,<i>Encyclopedia of German Tanks of World War II</i>, 1999</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"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130424163117/https://www.national1tracks.com/news/which-mtl-non-metal-core-rubber-track-right-your-business">Which MTL Non-Metal Core Rubber Track is Right for your Business?</a> National 1 Rubber Track</span></li> </ol> </div> <h2><span class="editsection">[<a href="/web/20130424163117/http://en.wikipedia.org/w/index.php?title=Continuous_track&action=edit&section=13" title="Edit section: External links">edit</a>]</span> <span class="mw-headline" id="External_links">External links</span></h2> <table class="metadata mbox-small plainlinks" style="border:1px solid #aaa; 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