57 mm AZP S-60

57 mm AZP S-60
S-60 in an Israeli museum
Type
Place of origin	Soviet Union
Service history
In service	1950–present
Used by	See users
Wars	Vietnam War Cambodian Civil War Cambodian–Vietnamese War Iran–Iraq War Gulf War Iraq War numerous others
Specifications
Weight	4,660 kg (10,273 lbs)
Length	8.5 m (27 ft 11 in)
Width	2.054 m (6 ft 9 in)
Height	2.37 m (7 ft 9 in)
Crew	7
Shell	57×348 mm. SR
Caliber	57 mm (2.24 in)
Rate of fire	105-120 rpm (cyclic) 70 rpm (sustained)
Muzzle velocity	1,000 m/s (3,281 ft/s)
Effective firing range	6,000 m (20,000 ft) (radar guided) 4,000 m (13,000 ft) (optically guided)

57 mm AZP S-60 (Russian: Автоматическая зенитная пушка С-60, abbrev. АЗП (AZP); literally: Automatic anti-aircraft gun S-60) is a Soviet towed, road-transportable, short- to medium-range, single-barrel anti-aircraft gun from the 1950s. The gun was extensively used in Warsaw Pact, Middle Eastern and South-East Asian countries.

In the late 1940s, the Soviets started to develop a 57 mm anti-aircraft gun, to replace its 37 mm guns. Three different models were presented, and the winning design was made by V. G. Grabin. According to western intelligence sources, the German prototype gun 5,5 cm Gerät 58 formed the basis for the design. The Soviets were also able to study German 5 cm Flak 41 guns that had been captured following the Battle of Stalingrad.

The prototype passed the field tests in 1946 and was accepted into service in 1950, after some minor modifications. The anti-aircraft gun was given the name 57 mm AZP S-60. Grabin continued the development and fielded the SPAAG version ZSU-57-2 in 1955.

The fire direction device was developed from the German Lambda calculator (Kommandogerät 40, 40A, and 40B) and was called PUAZO-5A. It had also a distance measuring device called D-49. The fire direction was also made more effective by including Grom-2 (10 cm wavelength) radars to the AA-batteries. The whole system was called SON-9. Later on, the calculators would be changed into the more modern RPK-1 Vaza, which had been designed by M. M. Kositskin. The calculator and the radars were transported by Ural 375 trucks.

The 57 mm gun replaced the 37 mm divisional guns in Soviet service in the 1950s. A divisional anti-aircraft regiment consisted of two AA-batteries with six 57 mm guns each. The PVO air-defence troops AA-regiments consisted of four 57 mm AA-batteries (24 guns).

In the mid-1960s, the Soviet divisional anti-aircraft units began replacing their AA-guns with missiles, and by the end of the 1970s, the AA-guns had almost disappeared. However, they were used in many other countries. The performance of AAA in Vietnam against low-flying aircraft led the Soviets to bring back many guns from storage to supplement the Surface-to-Air Missiles, whose performance at low altitude was less than satisfactory.