How do tank treads work

How does a tank tread work? How does a tank tread turn? What are the treads on a tank called? What are tank treads used for? How long do tank treads last? Are tank treads street legal? How much do tank treads cost? As the rider leans the deck side to side, the speed of the tracks change allowing for differential steering. A long line of patents disputes who the "originator" was of continuous tracks. There were a number of designs that attempted to achieve a track laying mechanism, although these designs do not generally resemble modern tracked vehicles.

The draft of Blinov 's steam-powered continuous track tractor. In Russian inventor Fyodor Abramovich Blinov created tracked vehicle called "wagon moved on endless rails" caterpillars. Blinov got a patent for his "wagon" the next year. Later, in he created a steam-powered caterpillar-tractor. This self-propelled crawler was successfully tested and showed at a farmers' exhibition in According to Scientific American , it was Charles Dinsmoor of Warren, Pennsylvania that invented a "vehicle" that was of endless tracks.

The article gives a detailed description of the endless tracks and the illustration looks much like today's tracked vehicles. Alvin O. Lombard of Waterville, Maine was issued a patent in for the Lombard Steam Log Hauler that resembles a regular railroad steam locomotive with sled steerage on front and crawlers in rear for hauling logs in the Northeastern United States and Canada.

Prior to then, horses could be used only until snow depths made hauling impossible. Lombard began commercial production which lasted until around when focus switched entirely to gasoline powered machines. After Lombard began operations, Hornsby in England manufactured at least two full length "track steer" machines, and their patent was later purchased by Holt in , allowing Holt to claim to be the "inventor" of the crawler tractor.

In a patent dispute involving rival crawler builder Best, testimony was brought in from people including Lombard, that Holt had inspected a Lombard log hauler shipped out to a western state by people who would later build the Phoenix log hauler in Eau Claire, Wisconsin, under license from Lombard.

This article does not contain any citations or references. Please improve this article by adding a reference. For information about how to add references, see Template:Citation. Linn had experimented with gasoline and steam powered vehicles and six wheel drive before this, and at some point entered Lombard's employment as a demonstrator, mechanic and sales agent.

This resulted in a question of proprietorship of patent rights after a single rear tracked gasoline powered road engine of tricycle arrangement was built to replace the larger motor home in on account of problems with the old picturesque wooden bridges. This dispute resulted in Linn departing Maine and relocating to Morris, New York, to build an improved, contour following flexible lag tread or crawler with independent suspension of halftrack type, gasoline and later diesel powered.

Although several were delivered for military use between and , Linn never received any large military orders. Most of the production between and , approximately units, was sold directly to highway departments and contractors.

Steel tracks and payload capacity allowed these machines to work in terrain that would typically cause the poorer quality rubber tires that existed before the mids to spin uselessly, or shred completely. Linn was a pioneer in snow removal before the practice was embraced in rural areas, with a nine foot steel v-plow and sixteen foot adjustable leveling wings on either side.

Once the highway system became paved, snowplowing could be done by four wheel drive trucks equipped by improving tire designs, and the Linn became an off highway vehicle, for logging, mining, dam construction, arctic exploration , etc. Diagram of tracked suspension. A sprocket wheel on a tank. 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. 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 , 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. The vehicle's weight is transferred to the bottom length of track by a number of road wheels, or sets of wheels called bogies. 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 absorbers.

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.

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. 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. Overlapped and interleaved road wheels of a German Tiger I heavy tank.

Many World War II German military vehicles, 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 tanks, generically known by the term Schachtellaufwerk in German.

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. 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.

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 World War II 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 vehicles equipped with such Schachtellaufwerk track suspension systems.

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 had to be removed to access the inner ones. Most UTVs are designed with 4 wheels. This is the most common structure because it allows it to do the following, to move quickly, easily controlled, or turn around in small places. Using the wheel, is not always the best case.

There are some situations where the wheels are not the best choice. In general, wheels are not used when:. The continuous band of treads driven by a series of wheels is used when the wheels cannot be used. In general, continuous tracks are used for:. BUT if we consider the current weather conditions outside our window as we are writing this article which is a lot snow I suppose the tracked systems win.