PT-76

The PT-76 (Plavaushiy Tank, "swimming tank") is a Soviet light amphibious tank designed by the heavy-tank design bureau at the Kirov Plant in Leningrad, which also produced the IS series. Loosely based on an earlier cross-country vehicle, it entered production in 1953. Cheap and simple, it was exported to many countries and fought in the Middle East, Africa, the Far East and the 1991 Gulf War. When it appeared, no NATO army had an amphibious scout tank.

Design

The hull and turret are all-welded steel. The driver sits at the centre front, and the turret holds two or three crew. In the original layout a commander-gunner sat left of the gun and a loader on the right; in the three-man turret a separate commander sat behind the gunner. The main gun is a 76.2 mm weapon: the early D-56T with a multi-baffle muzzle brake, and later the D-56TM with a simpler brake and fume extractor.

The engine is a 240 hp in-line six-cylinder diesel, effectively half of the V-54 V12 used in the T-54. Besides driving the rear sprockets, it powers pumps feeding two hydrojets that discharge through ports in the stern plate. The tank is steered afloat by opening and closing intake ports on the rear hull sides. To swim, the crew only has to raise the bow trim vane and switch on the bilge pumps. Freeboard is only a few inches, though, and the engine floods easily. The raised vane blocked the driver's view, so early tanks relied on the commander for directions until a periscope extension was added. The PT-76 reaches about 35 mph (56 km/h) on land and 4 mph (6.4 km/h) in the water, carrying about 250 litres of fuel internally, with extra drums on the rear deck of later models.

Combat

US forces first met the PT-76 in Vietnam in 1967 during a North Vietnamese attack on the Special Forces camp at Lang Vei. A second attack the following year overran the camp. In March 1969, at Ben Het, eight PT-76s attacked a camp defended by five dug-in M48 Pattons and withdrew after losing two vehicles.