Caterpillar Drive

a means by which a self-propelled machine can operate on all types of terrain. Caterpillar drives are based on the operating principle of a continuous laying-down of treads under a machine’s wheels, that is, of the placing under the wheels of an endless path that offers less resistance to movement than soft soil would offer. The large bearing surface area of the treads on soil reduces the unit pressure to a low figure: 30–50 kilonewtons per sq m (0.3–0.5 kilograms-force per sq cm), that is, less pressure than is produced by a person’s foot. This prevents the Caterpillar treads from sinking into the soil. A machine on Caterpillar treads can achieve speeds of 50–70 km/r.

Caterpillar drives are used on machines designed to function in roadless areas, soft soils, swamps, or deep snow. These include tractors, machinery for felling and skidding trees, mine loaders, cutter-loaders, peat loaders, road machines, excavators, pipelayers, cranes, and so on, as well as military equipment such as tanks, tractors, and selfpropelled artillery.