K-61

The K-61, also known as the GPT or PTG, is an unarmoured tracked amphibious transporter developed in the Soviet Union shortly after the Second World War and in Soviet service from the early 1950s. Its role was to ferry troops, artillery, vehicles and supplies across wide rivers in assault crossings, and to carry loads over swampy ground. It was exported to most Warsaw Pact countries as well as Egypt and Vietnam, and was later replaced in front-line units by the larger PTS.

Design

The welded all-steel hull is watertight. The commander and driver sit at the front behind a windscreen that folds forward, with no enclosed cab; the rest of the hull is an open cargo area closed at the rear by a tailgate that serves as a loading ramp, and a winch driven by the main engine hauls non-self-propelled loads aboard and can also be used for self-recovery. Bows and a tarpaulin can cover the whole load space.

Each side has seven small road wheels, a front drive sprocket and a rear idler. Unusually for a Soviet tracked vehicle it has no return rollers: the upper run of the narrow track slides along support rails. Afloat, two three-bladed propellers in tunnels at the rear drive the vehicle while the tracks stand idle; rudders behind the propellers steer, and counter-rotating the propellers turns it on the spot. Two bilge pumps (about 800 l/min together) plus a hand pump deal with leaks.

The K-61 carries 3 tonnes on land and 5 tonnes in water: 40 to 60 troops, eight stretcher cases, or a load such as a 122 mm gun, 152 mm howitzer, 120 mm mortar or an unladen ZIL-157, GAZ-63 or ZIL-130 truck. Top speed is about 36 km/h on roads and 10 km/h in water, with a range of roughly 260-300 km.

Service

Soldiers nicknamed it 'Pap' and disliked it for its many faults: it was underpowered, noisy because of the slide rails, its engine started badly in winter, its narrow tracks were fragile and liable to come off in sharp turns, and when loaded it had only 15-20 cm of freeboard, so it swamped easily and the bilge pumps could not cope. In Soviet service amphibious engineer companies of divisions had a platoon of nine, and separate amphibious engineer battalions 36. Egypt used K-61s to ferry supplies across the Suez Canal in the 1973 war.

Variants

• K-61 ferry: two vehicles linked by two treadways with ramps at each end, carrying about 7 tonnes.
• Recovery/repair version with an A-frame crane at the front and a stronger winch.
• A drilling-rig version with a tower at the rear.
• GSW, the East German army designation.
• Users also included Poland, Yugoslavia and Croatia.