Editing Continuous track (section)

=== Construction and operation ===
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 can be made of manganese alloy steel for high strength, hardness, and abrasion resistance.<ref>{{cite web |url=http://www.keytometals.com/page.aspx?ID=CheckArticle&site=kts&NM=69 |title=Austenitic Manganese Steels |access-date=2011-08-24 |url-status=live |archive-url=https://web.archive.org/web/20120308160132/http://www.keytometals.com/page.aspx?ID=CheckArticle&site=kts&NM=69 |archive-date=2012-03-08 }}</ref>

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 [[Unsprung mass|unsprung]], 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.

The vehicle's weight is transferred to the bottom length of track by a number of road wheels, or sets of wheels called [[bogie]]s. While tracked construction equipment typically lacks suspension due to the vehicle only moving at low speeds, in military vehicles 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 [[shock absorber]]s. [[Torsion-bar suspension]] 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 [[idler-wheel]] and sometimes the sprocket.

<gallery heights="180px" mode="packed">

File:Bundesarchiv Bild 101I-635-3965-28, Panzerfabrik in Deutschland.jpg|Overlapped and interleaved road wheels of a German [[Tiger I]] heavy tank
File:Bundesarchiv Bild 101I-750-0001A-05A, Bau von Zugkraftwagen 3t (Sd.Kfz. 11).jpg|upright|An [[Sd.Kfz. 11]]'s half-track units, showing the rims of its six ''Schachtellaufwerk'' overlapped/interleaved roadwheel sets for each track unit per side
</gallery>

==== Overlapping road wheels ====
Many World War II German military vehicles, initially (starting in the late 1930s) including all vehicles originally designed to be half-tracks and all later tank designs (after the [[Panzer IV]]), had slack-track systems, usually driven by a front-located drive sprocket, the track returning along the tops of a design of overlapping and sometimes interleaved large diameter road wheels, as on the suspension systems of the [[Tiger I]] and [[Panther tank|Panther]] tanks, generically known by the term ''Schachtellaufwerk'' (interleaved or overlapping running gear) in German, for both half-track and fully tracked vehicles. There were suspensions with single or sometimes doubled wheels 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.<ref>Peter Chamberlain and Hilary Doyle, ''Encyclopedia of German Tanks of World War II'', 1999</ref>

The choice of overlapping/interleaved road wheels allowed the use of slightly more transverse-orientation [[torsion bar]] 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, ensuring greater traction and more accurate fire. However, on the Russian front, mud and snow would become lodged between the overlapping wheels, freeze, and immobilize the vehicle. As a tracked vehicle moves, the load of each wheel moves over the track, pushing down and forward that part of the earth or snow underneath it, similarly to a wheeled vehicle but to a lesser extent because the tread helps distribute the load. On some surfaces, this can consume enough energy to slow the vehicle down significantly. 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.{{Citation needed|date=December 2016}} The wheels also better protect the vehicle from enemy fire, and mobility is improved when some wheels are missing.

This relatively complicated approach has not been used since World War II ended. This may be related more to maintenance than to original cost. The torsion bars and bearings may stay dry and clean, but the wheels and tread work in mud, sand, rocks, snow, and other surfaces. In addition, the outer wheels (up to nine of them, some double) had to be removed to access the inner ones. In WWII, vehicles typically had to be maintained for a few months before being destroyed or captured{{Citation needed|date=December 2016}}, but in peacetime, vehicles must train several crews over a period of decades.

==== Drive train ====
Transfer of power to the track is accomplished by a [[drive wheel]], or ''drive [[sprocket]]'', 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 ''idler'', 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 ''slack track'', allow the track to droop and run along the tops of large road wheels. This was a feature of the [[Christie suspension]], leading to occasional misidentification of other slack track-equipped vehicles.

==== Steering ====
Continuous track vehicles [[steering|steer]] by applying more or less drive torque to one side of the vehicle than the other, and this can be implemented in a variety of ways.
{{Main|Differential steering}}