Tank, Amphibious

an armored, tracked combat vehicle capable of crossing water obstacles under its own power and of waging battle on land and water. The tank is made buoyant by a hermetically sealed body of the required interior volume. The tank is propelled on the water by such devices as screw propellers, caterpillar tracks, and hydrojet units.

The first amphibious tank, the T-37, was adopted by the Red Army in 1932. By 1940 it was replaced by the T-38 and T-40. During World War II (1939–45), the US armed forces used amphibious tanks for fire support of landing parties in several landing operations. After the war, amphibious tanks became common in the armed forces of many countries.

The PT-76 amphibious tank has been developed by the USSR. It weighs 14 tons, has a crew of three, and travels 44 km/hr on an unobstructed road and 10 km/hr in the water. Its armament consists of a 76-mm cannon and a coaxial 7.62-mm machine gun. The armored hull is welded from individual sheets of special armor steel. The turret can be traversed by manual or electric power control, thus providing a 360° field of fire. The tank has two hydrojet engines located in the engine compartment along the sides of the body. In case of battle damage, the hydrojet units can operate as bilge pumps.