ASU-57

ASU-57
Type	Airborne Tank Destroyer / Assault Gun / Tankette
Place of origin	USSR
Service history
In service	1951- late 1960s (USSR)
Used by	USSR Egypt Vietnam Yugoslavia Ethiopia
Wars	Six Day War Ogaden War
Production history
Designer	Astrov Design Bureau
Manufacturer	MMZ
Produced	1950-1962
Specifications
Weight	3.4 tonnes
Length	3.48 m (11 ft 5 in) (hull)
Width	2.08 m (6 ft 10 in)
Height	1.18 m (3 ft 10 in) (shield up)
Crew	3+6
Armor	6 mm
Main armament	1x Ch-51 or Ch-51M L/73 57mm Gun
Secondary armament	1x 7.62mm anti-aircraft machine gun
Engine	one M-20E4 water cooled gasoline engine 50hp (37.29 kW) (55hp with later engine)
Suspension	torsion bar
Fuel capacity	140 liters (37 gallons)
Operational range	250 km (160 mi)
Speed	45 km/h (28 mph)

The ASU-57 was a small, lightly constructed Soviet assault gun specifically designed for use by Soviet airborne divisions. From 1960 onwards, it was gradually phased out in favour of the ASU-85.

The task to develop a light-weight assault gun for the airborne troops (with either a 57mm gun or a 76mm gun) was given to two design bureaus, Astrov (OKB-40) in Mytishchi and Kravtsev in Moscow. Nikolaj Astrov's OKB-40 designed the ASU-76, based on components of the T-70 light tank and the SU-76 assault gun, and armed with the new 76mm gun D-56T. The ASU-76 turned out to be too heavy, even though the armour was only 3 mm thick, and the project was cancelled. Anatoly Kravtsev's team came up with the similar, amphibious K-73. This vehicle was armed with Charnko's 57mm anti-tank gun Ch-51 and was even more thinly armoured than the ASU-76. This project too was shelved.

In 1949, Astrov was instructed to continue with his project, but with reduced weight and with the Ch-51 gun as the main armament instead of the D-56T, since it offered better anti-tank performance. The redesigned Ob.572 was developed simultaneously with the Ob.561 (AT-P) light artillery tractor. After successfully passing the various test phases in 1949, it was accepted for series production from 1951 as the ASU-57.

The ASU-57 was designed to be a light-weight assault gun that could be air-dropped and deployed by rocket-assisted parachute (PP-128-500 or P-7) along with the troops. It was lightly armored and armed with a 57 mm gun Ch-51, a development of the World War II ZIS-2 but with some similarities to the Ch-26. From 1954, an improved 57mm gun Ch-51M with a much shorter double-baffle muzzle brake was fitted. The gun fired the standard caliber 57x480R ammunition of the ZIS-2 anti-tank gun, such as the BR-271 series and the O-271U, of which it had 30 on board. The ASU-57's engine was taken from the GAZ-M-20 "Pobeda" civilian car.

The ASU-57 was a successful design that saw service with Soviet airborne divisions for around 20 years before being replaced by the ASU-85. During its years of operation, 54 vehicles would have been assigned to each airborne division.