A tank that can't traverse broken or muddy terrain isn't going to be much use to anyone, and thus significant thought was given to the makeup of the suspension of German and Soviet tanks. While the Germans pursued ever more complex and versatile suspension, the Soviet engineers became famous for incorporating ruggedness and mechanical reliability into their more simple suspension systems.

The basic elements of a tank's suspension are its drive wheels, its roadwheels, its idler wheels, and its return rollers . The configuration of the roadwheels could produce a variety of different suspension systems, while the position of the drive wheels/idler wheels would produce different degrees of torque (how much engine horsepower would be converted into actual movement).

The most basic idea of a tank's drive system and suspension is as follows. The various wheels of a tank's suspension form a "frame" around which the tank's treads are laid. As the drive wheel turns, its gear teeth grip the treads and make them run around the other wheels in the tank's suspension much the same way a conveyor belt's belt moves over the rollers. The tread has a much greater grip on the ground than normal wheels would, and thus the tank can traverse a much greater variety of terrain than a normal wheeled vehicle.

The drive wheel is one of the most important parts of the tanks drive system, for without it the tank is incapable of movement. The drive wheel is directly connected to an axle leading (through a series of connections and the transmission) to the engine, which is the tank's main source of power. As the axle turns, the drive wheel's gear teeth grip the treads and force them around the rest of the tank's suspension system (the idler wheel, roadwheels, and (on German tanks) return rollers).

HOW TO LOCATE A TANK'S DRIVE WHEEL

The drive wheel is a wheel without any rubber around its circumference located at the rear (Soviet) or front (German) of the suspension system.