The ZSU-57-2 (Ob'yekt 500) is a Soviet self-propelled anti-aircraft gun armed with two 57 mm autocannons. ZSU stands for Zenitnaya Samokhodnaya Ustanovka (Зенитная Самоходная Установка), meaning \"anti-aircraft self-propelled mount\", 57 stands for the bore of the armament and 2 stands for the number of gun barrels. It was the first Soviet mass produced tracked SPAAG. In the USSR it had the unofficial nickname \"Sparka\", meaning \"pair\", referring to the twin autocannon with which the vehicle is armed.
During the World War II, ground-attack aircraft emerged as a significant threat to mechanized units on the march or on the offensive. Conventional towed AA artillery was an inadequate response under such conditions due to time necessary for arming. Anti-aircraft machine guns, such as the 7.62 mm Soviet quad Maxims mounted on trucks proved to be inefficient.
These first war experiences made it clear that an anti-aircraft tracked vehicle armed with small-bore autocannons or heavy machine guns that could provide mobile units with good AA protection would be very necessary on a battlefield. Such vehicles (Wirbelwind) were used by Germans in the final battles of World War II.
In 1942, Soviet engineers developed the T-60-3 SPAAG that could keep up with tank columns. The vehicle based on the T-60 light tank chassis and armed with two 12.7 mm DShK heavy machine guns; the prototype did not go into production because of design defects. The SU-72 SPAAG and several other experimental vehicles based on the T-60 or T-70 light tank chassis and armed with 37 mm autocannon were tested in 1942-1943 until the reliable construction was build. That was the ZSU-37 based on the SU-76M SPG chassis and armed with 37 mm 61K anti-aircraft autocannon in a open-top rotatory armoured turret. The vehicle entered production in February 1945 and was in small-scale production until 1948.
After World War II it became clear that the inadequate firepower of a single 37 mm AA autocannon was not effective against high-speed, low-altitude targets. Also, SPAAGs based on light tank chassis had poor maneuverability in difficult terrain, slow off-road speed and insufficient range in comparison with medium tanks and SPGs. Thus the ZSU-37s were retired from service by the end of the 1940s.
For several years after the World War II there were not any new serial models of SPAAGs in the USSR except for the mass produced BTR-152A (armed with 2 or 4 x 14.5 mm KPV heavy machine guns, such vehicles were designated ZTPU-2 or ZTPU-4, correspondingly) and BTR-40A (ZTPU-2) wheeled SPAAGs. The need for a new tracked AA vehicle was apparent after World War II. Two of the USSR's potential enemies - the United States of America and United Kingdom - had high-quality air forces with substantial ground-attack experience.
In February 1946 the Design Bureaus of Works No. 174 in Omsk and Research Institute No. 58 in Kaliningrad, Moscow Oblast submitted a joint project for a SPAAG based on the T-34 tank chassis armed with four 37 mm AA autocannons to the Technical Council of the Ministry of Transport Vehicles. However, the project did not proceed due to the desire to concentrate attention on the newest tank chassis available for a new SPAAG.
The Design Bureau of the Research Institute No. 58 (NII-58) (formerly known as the Central Artillery Design Bureau, TsAKB) under the supervision of V.G. Grabin started the development of 57 mm S-68 twin automatic anti-aircraft gun based on two 57 mm S-60 AA autocannons in the spring of 1947. The first S-68 prototype with ESP-76 electric drive as the main armament for the new SPAAG was ready in 1948. It was mounted on the S-79A four-wheel carriage at first, that system passed tests but did not go into production.
The final project of the ZSU-57-2 (Ob'yekt 500), armed with the S-68 twin autocannon and based on a light-weight T-54 medium tank chassis, was finished in 1948. The first prototype ZSU-57-2 was built in June 1950 and the second one in December 1950 (after factory tests). After official tests which took place between 27 January and 15 March 1951 (the vehicle passed 1,500 km and performed 2,000 rounds from its autocannon), six more prototypes of the ZSU-57-2 were built for service tests. Those prototypes had some improvements including the increased ammunition load (300 rounds) but development stopped again due to the absence of improved S-68A cannons for them. Various updates continued in 1952 and 1953. The service tests, in which two vehicles participated, took place in December 1954 only due to delays in the development of drives for the S-68 twin AA autocannons. The ZSU-57-2 officially entered service in the Soviet Army on 14 February, 1955.
Basing on past experiences with SPAAG designs, Soviet engineers designed a vehicle that used a modified T-54 chassis, with four twin road wheels per side instead of five, and with much thinner armour. The vehicle was armed with the 57 mm S-68 twin AA autocannon in a new large rotatory open-topped turret. The ZSU-57-2 consists of three compartments: driver's in the front, fighting in the middle and engine-transmission in the rear. The hull of the ZSU-57-2 is more spacious in comparison with the T-54 medium tank because of the thinner armour and has different location of some equipment also. The general layout with transverse mounting of engine is the same.
Driver's compartment is located on the left hand side of the front of the hull. The driver's seat was moved forward to the left in comparison with its location in the T-54 medium tank. The compartment is equipped with a single-piece hatch cover opening to the left and with two periscopic vision devices. One of them can be replaced by the TVN-1 infrared vision device which is operated together with the infrared headlamp mounted on the right track board. A fire-fighting equipment signal panel and a spare part case are located in the driver's compartment also.
The open-topped box type welded turret has a ball-bearing race ring 1850 mm in diameter. The turret rear can be removed which makes the replacement of cannons easier. The turret can be covered in travelling position by a tarpaulin with 16 plexiglass windows which is fixed on turret top by bows and straps. When not in use, the tarp can be rolled up and stowed on the turret side.
To aim the gun the following base data has to be entered into the sighting system by the sight adjuster (who sits from the left of the autocannon in the rear part of the turret): target's speed, target's course angle and the range to the target (if necessary - also dive angle or pullup angle of the target). Target's speed and direction was determined by visual estimation, range can be estimated visually or by the rangefinder. The upper front side of the turret has two small ports with armoured covers meant for collimators of the sight.
To fire, the gun breeches must be opened. The left and right loaders (who stay in the forward part of the turret on both sides of the twin autocannon) load clips into magazines of corresponding barrels. The loader's travel seats should be stowed in clamps on the turret rotatory suspended floor before opening fire. The gunner (who sits on the left hand side in the middle part of the turret) aims the gun and opens fire using an electric (common) or a pedal (individual for each barrel) trigger. If manual mechanical drive is used instead of electrohydraulic drive three crewmembers instead of two should work with the sight: the commander (who sits on the right hand side in the middle part of the turret) aims the gun in azimuth, the gunner aims the gun in elevation and the sight adjuster enters data into the sight. The loaders feed clips into the twin autocannon manually as needed.
The S-68 twin AA recoil-operated autocannon weighs 4,500 kg and its construction was based on two 57 mm S-60 AA autocannons. The gun has a recoil between 325 mm and 370 mm. The individual weapons cannot be swapped from one side to the other; they are nearly identical but are mirror images. Each air-cooled gun barrel with muzzle brake is 4.365 m long (76.6 bores). The S-68 twin AA autocannon can be elevated or depressed between -5° and +85° with a speed between 0.3° and 20° per second, and the turret can traverse 360° at a speed between 0.2° and 36° per second. Drive is from a direct current electric motor and universal hydraulic speed gears (a manual mechanical drive is also provided in case of electrohydraulics failure; with the use of mechanical drive the autocannon elevation speed is 4.5° per second and the turret traverse speed is 4° per second).
The S-68 twin gun is capable of firing up to 210-240 fragmentation and armour-piercing tracer rounds per minute, with a practical rate of fire between 100 and 140 rounds per minute. Muzzle velocity is 1,000 m/s. Each clip has 4 rounds each of which weighs 6.6 kg (round charge consists of 1.2 kg of 11/7 nitro-cellulose powder, a projectile itself weighs 2.8 kg). Maximum horizontal range of fire is 12 km (with an effective range against ground targets up to 4 km / 2.5 miles) and maximum vertical range of fire is 8.8 km (with an effective vertical range up to 4.5 km / 14,750 ft). Fragmentation rounds have safety-destructor which activates between 12 and 16 seconds after being fired (so maximum slant range of anti-aircraft fire is 6.5-7 km). BR-281 armour-piercing rounds are able to penetrate 110 mm armour at 500 m or 70 mm armour at 2,000 m (at 90° impact angle).
The S-68 autocannon was the most powerful AA gun installed on serial SPAAGs of that time. According to the statistical data of Air Defense Research Institute No. 2 a direct hit of a single 57 mm shell could destroy a contemporary jet aircraft. In order to shoot down a jet bomber of Canberra-type an average of 1.7 hits were necessary. There are two ways of automatic fire: with block of the last round in the round clip and without block.
The vehicle carries 300 rounds of ammunition stowed as follows: 176 rounds in clips inside the turret, 72 rounds in clips in the hull front, and 52 separate (unclipped) rounds in special compartments under the turret floor). Armour-piercing rounds in clips are placed in the rear part of the turret to the left and to the right sides from the autocannon mount. Empty shell cases and clips are emptied in original way: through a special port in the turret rear into an external metal wire basket on the back of the turret via a belt conveyor.
The ZSU-57-2's armour is welded rolled steel sufficient to protect the vehicle from 7.62 mm armour-piercing bullets at 250 meters.
Armour thickness is as follows:
The ZSU-57-2 has a maximum road speed of 50 kilometres per hour, reduced to around 30 kilometres per hour off-road. The vehicle has better accelerating capacity in comparison with the T-54 tank because of increased power-to-weight ratio (18.6 hp per tonne). The ZSU-57-2 has an operational range of 420 km on road and 320 km cross country. The vehicle can cross 0.8 m high vertical obstacles, 2.7 m wide trenches, ford 1.4 m deep water obstacles and climb 30° gradients.
The ZSU-57-2 uses the same V-54 12-cylinder four-stroke V-shaped 38.88 liter water-cooled diesel engine developing 520 hp (388 kW) at 2,000 rpm as the T-54 tank. The engine itself weighs 895 kg. Fuel capacity is 830 liters carried in three fuel tanks inside the hull (640 l total) and two external fuel tanks on the right fender (95 l each); fuel capacity was increased in comparison with the T-54 tank. External rear-mounted supplemental fuel tanks can increase the range to 595 km on road.
The mechanical transmission in the rear part of the hull consists of a change gear quadrant, a multiplate main clutch of metallic contact, manual gearbox with five forward gears, two multiplate planetary steering clutches with band brakes and two in-line final drive groups.
The chassis has four twin rubber tired road wheels with individual torsion bar suspension, rear drive sprocket with detachable sprocket rings (lantern-wheel gear) and idler wheel per side. The first and last road wheels have a hydraulic rotary shock absorber. The track is 12.33 m long, 580 mm wide and has 90 links; despite having four road wheels instead of five the ground contact area of the track is the same as the T-54 tank (3.84 m). The track center distance is 2.64 m The vehicle has a ground pressure of 0,63 kg/cm².
The electrical power units of the ZSU-57-2 partially differs from the T-54 medium tank and consisits of more powerful G-74 direct current generator developing 3 kW (108 A at 27-29 V) at 2100 rpm and six 24 V voltage 6-STEN-140M or 6-MST-140 accumulator batteries (total batteries capacity is 420 A-h), the accumulator batteries are used for starting of engine and electric power supply when generator is shut down.
The ZSU-57-2 is equipped with an automatic anti-aircraft sight of plotter type with two collimators which can supervise a target having speed up to 350 m/s with a dive angle between 0° and 90° at a slant range up to 5,500 m; a simple mechanical sight is provided in case of automatics failure. There is also an optical sight for direct fire at ground targets.
The 10RT-26E portable radio transceiver locates on the right hand side inside the turret and it has a range from 9 to 20 km when the vehicle is stationary, and from 7 to 15 km when the vehicle is on the move; it was later replaced by R-113 or R-123 radio transceivers. The TPU-4-47 intercom system was later replaced by R-120 or R-124 intercom systems.
Small arms for the crewmembers included two AK-47 assault rifles and a 26 mm signaling pistol.
The main weakness of the ZSU-57-2 was the lack of search or fire-control radar; the vehicle was equipped with an optical mechanical computing reflex sight as the sole fire control system, so it could engage visible targets only. For this reason, night firing was also impractical. Also, the manual gunlaying and manual clip loading was not good enough, the rate of fire not high enough (air-cooled barrels also require quite long pauses for cooling at high rates of fire) and the turret traverse not fast enough to effectively intercept high-speed attack jet aircraft at low altitudes. The vehicle also could not perform aimed fire on the move.
Although the ZSU-57-2 had the highest firepower among production SPAAGs of its time, the anti-aircraft fire efficiency of a battery of four ZSU-57-2 was even lower than that of a battery of six towed 57 mm S-60 anti-aircraft autocannons controlled by PUAZO-6 anti-aircraft artillery director with SON-9 gun fire control radar or later by RPK-1 Vaza radar facility. It became obvious that the hit probability on a jet aircraft of the era was very low using only determination of target speed by aircraft type and determination of distance to target by eye or by the rangefinder. This was mostly due to the fact that the ZSU-57-2 was designed to defend tank units against NATO attack aircraft flying at subsonic speeds, but it entered service ten years later. In the meantime, aircraft technology had improved to the point that an SPAAG required a much higher rate of fire, turret traverse speeds of 50-100° per second and a fully automatic radar-controlled fire control system. The Works No. 174 started a modernization program for ZSU-57-2 in parallel with the beginning of its serial production in 1957 but the program was rejected due to the development of new radar-guided SPAAGs armed with small-bore autocannons and used another tracked chassis.
The ZSU-57-2 still retained some of the features of its predecessor, the ZSU-37. One of them was the lack of an armored roof on the turret. The advantages of open turret for SPAAGs such as very high elevation angle for AA autocannons, excellent visibility of combat situation by gunners and no need for induced ventilation of the fighting compartment during intense fire were significantly diminished by post-WWII warfare. The open turret of the ZSU-57-2 made it vulnerable from above, and prevented operations under NBC conditions. This flaw was partially nullified in modified Bosnian Serb ZSU-57-2s which had improvised overhead armour protection.
Nevertheless, it must be noted that its Western counterparts operationally available in 1950s such as the US M19 GMC based on the M24 Chaffee light tank, US M42 Duster SPAAG (both armed with the famous 40 mm Bofors M2A1 twin AA autocannon) and British Crusader AA SPAAG armed with the single 40 mm Bofors AA autocannon had similar problems and were armed with less powerful autocannons. The M42 Duster was modernized and equipped with a T50 radar system in 1956 (when series production of Soviet ZSU-57-2 SPAAG was not started yet)
Mass production of the ZSU-57-2 started in 1957 when the first 249 57 mm S-68 twin AA autocannons for ZSU-57-2 were produced by Artillery Works No. 946 located in Krasnoyarsk (a total of 5,300 S-68 twin AA autocannons was produced till the end of 1950s). The hull, the turret and the final assembly were done at Works No. 174 located in Omsk while Krasnoyarsk Works belonging to the Ministry of Heavy Engineering participated in some production stages. ZSU-57-2 remained in production until 1960. Also at least 250 ZSU-57-2 SPAAGs based on Chinese Type 59 (copy of Soviet T-54A) tank chassis were produced under license in North Korea.
The ZSU-57-2 officially entered service with the Soviet Army in 1955. The first vehicles started replacing BTR-40As and BTR-152As in anti-aircraft batteries of tank regiments in 1957. It was first shown publicly during the military parade in Moscow on 7 November, 1957. A number of Soviet tank regiments received ZSU-57-2s, but many continued to use towed S-60 57 mm AA autocannons or wheeled BTR-40As and BTR-152As instead due to insufficient supplies of ZSU-57-2s.
Initially, tank regiments had a single AA artillery battery equipped with four SPAAGs, however, later tank regiments had an AA artillery battalion (which consisted of two artillery batteries, each equipped with four SPAAGs). The vehicle was also used by some motor rifle regiments (which in the 1960s had one AA artillery battery equipped with four SPAAGs or, much more often, with six 23 mm ZU-23 towed twin AA autocannons). The anti-aircraft performance of the ZSU-57-2, however, was quickly found to be unsatisfactory and, because of rapid air force development, the vehicle was deemed to be obsolete by the early 1960s.
Soviet ZSU-57-2s were gradually replaced by radar-guided ZSU-23-4 Shilkas in the beginning of 1965. Towards the end of the 1960s, a frequent configuration was one battery of AA artillery battalion of a tank regiment equipped with ZSU-23-4s and another battery equipped with ZSU-57-2s. Unpopular in the Soviet Army ZSU-57-2s were completely replaced by ZSU-23-4s by the early 1970s. Unlike the ZSU-57-2, the ZSU-23-4 was very effective, equipped with a radar and armed with smaller caliber 4 x 23 mm autocannons with a much higher rate of fire. Most of the ZSU-57-2s were put into reserve storages while a few remained in service in Soviet tank training centers (as vehicles for driver training) till the end of the 1970s at least. Some ZSU-57-2s were converted by army workshops into bulldozers. The last Soviet ZSU-57-2s were scrapped in the 1980s, some dismantled vehicles were used as gunnery range targets One ZSU-57-2 SPAAG is preserved in Kubinka Tank Museum
ZSU-57-2s were exported like other Soviet equipment. Five other Warsaw Pact members (Poland, East Germany, Hungary, Bulgaria and Romania) used it, as well as Cuba, Egypt, Iran, Iraq and Syria. North Vietnam and North Korea may have received theirs without payment.
The first foreign operator of the ZSU-57-2 was East Germany in 1957. From 1957 to 1961 the National People's Army received 129 ZSU-57-2s, eventually replacing them with ZSU-23-4s between 1967 and 1974. The ZSU-57-2 was completely gone from East German service by 1979. Some of the vehicles were converted into FAB 500U training vehicles for T-54 tank drivers and were passed on to the unified German state.
Poland received its 129 ZSU-57-2s between 1957 and 1961. Poland was also offered a production license for S-68 twin AA autocannons, however, Poland declined. Eventually Poland replaced all its ZSU-57-2s with ZSU-23-4s. Seven Polish ZSU-57-2s are preserved, one at Lubuskie Military Museum in Drzonów, one in Wicko Morskie, the largest anti-aircraft artillery firing range in Poland, one at Museum Land Forces in Warsaw, one at History and Tradition of Suvalkai Soldiers Museum in Suwalszczyzna, one in Koszalin and two at Polish Army Museum in Warsaw.
Three other Warsaw Pact members, Hungary, Bulgaria and Romania, received ZSU-57-2s after the ZSU-57-2 started to be replaced with more modern ZSU-23-4s in the Soviet Army. Czechoslovakia imported one ZSU-57-2 for testing but they refused it because the domestically produced M53/59 Praga SPAAG (also called "Ještěrka") based on Praga V3S 6x6 truck with armoured cabin and armed with 30 mm twin AA autocannon was considered by the Czechoslovakian Army to be comparable to the ZSU-57-2.
The Socialist Federal Republic of Yugoslavia ordered 100 ZSU-57-2s in 1963. The deliveries were completed between 1963 and 1964. They were passed on to the successor states during the 1992 breakup of the Yugoslavian state. They were then used by Federal Republic of Yugoslavia. There were 54 of those vehicles in 1999 and this number decreased to 36; they were withdrawn from active service by 2003. However, they remained in possession of the Yugoslav military, and after the creation of Serbia and Montenegro they were scrapped. Two ZSU-57-2s captured by Croatian forces during the Croatian War of Independence were also scrapped.
The air defense battery of the 44th "Wolfs" armoured-mechanized battalion stationed in Pivka and belonged to 4th Regional Command Postojna is equipped with ZSU-57-2s.
Finland imported 24 ZSU-57-2 SPAAGs between 1960 and 1961 alongside other kinds of Soviet equipment. They were designated ItPsv SU-57 and some of them remained in service to the end of the century. A ZSU-57-2M modernization was being developed in Finland which equipped the vehicle with a radar and configurable ammunition. However after the prototype was produced the project was abandoned because of high costs.
People's Republic of China did not import the system from the USSR in 1950s, but was approached by Iraq in the early 1980s to develop a copy of the ZSU-57-2 system and few examples were delivered to the PRC for reverse-engineering. To meet Iraq's production order, NORINCO attempted to manufacture a copy with the improved amphibious chassis of Type 69-II main battle tank produced by IMFMW (Inner Mongoolia First Machinery Works, the only tank manufacturer in China). Several Type 80 SPAAGs were tested and accepted into service by the PLA. It entered service in small numbers. It was originally intended for the export market but didn't sell well. Much bigger success however was achieved by Chinese made proximity fuzes which could be used to modernize the S-60 and S-68 ammunition.
The Iraqi Army received 100 ZSU-57-2s in the early 1970s. The Iraqis also assembled a single S-60 AA autocannon in a square-sided platform mount with drop down sides and rear onto old T-55 tank hulls. The New Iraqi Army does not use these vehicles and the only SPAAGs it uses are BRDM-2s armed with ZPU-2 twin 14.5 mm KPV machine guns instead of a turret (See BRDM-2 for details).
Iran bought 100 ZSU-57-2s in the 1970s which remained in service until 2002. Egypt received its first ZSU-57-2s shortly before the Six Day War in 1967. ZSU-57-2s were not very successful during either that conflict or the Yom Kippur War in 1973. Despite that, the Egyptian Army operated 40 ZSU-57-2s as late as 2003 and equipped them with radar. Egypt also bought Chinese-made proximity fuzes for its S-60 and S-68 ammunition. Israelis captured a number of ZSU-57-2s from Egyptians or Syrians. One was given to the Yad la-Shiryon Tank Museum in Latrun, another one was given to Batey ha-Osef museum of the history of the Israeli Defense Forces in Tel Aviv and the third one (captured in 1973) - to Israeli Air Force Museum in Hatzerim.
The ZSU-57-2 was used in combat for the first time in the Vietnam War by the Vietnam People's Army beginning with the Easter Offensive in 1972, and again during the Ho Chi Minh Campaign in 1975. Several batteries of ZSU-57-2s were used for AA defense of the 201st and 202nd tank regiments during the Easter Offensive of 1972. The ZSU-57-2s were used by the VPA against US aircraft but it proved to be a very effective weapon against ground targets. The ZSU-57-2 was expensive to operate, which was why the Chinese developed the Type 65 SPAAG based on the T-34 medium tank chassis for Vietnamese troops (see People's Republic of China section in T-34 variants). South Vietnam also used captured ZSU-57-2s. About 500 ZSU-57-2s survived the war with 200 currently still in service with the Vietnam People's Army.
ZSU-57-2s were used during several conflicts in the Middle East including the Six Day War in 1967 and the Yom Kippur War in 1973. A battery of Egyptian ZSU-57-2s together with the T-34 medium tanks defended El-Arish takeoff strip and they were broken by company of Israeli M48 Patton main battle tanks belonged to the 7th armoured brigade during an intense combat on 6 June, 1967.ZSU-57-2s were not generally successful and a number fell to the hands of the Israeli military. The Syrians used ZSU-57-2s against ground targets during the 1982 Lebanon War.
During the Iran–Iraq War, ZSU-57-2s were used by both Iraq and Iran. Iraq also used Chinese Type 80s during this conflict and the First Persian Gulf War. Iraqi ZSU-57-2s, which could receive information from the radars on ZSU-23-4s or 9K31 Strela-1 (SA-9 Gaskin)/9K35 Strela-10 (SA-13 Gopher) surface-to-air missile systems were employed against Iranian AH-1J SeaCobra attack helicopters.
On January 16, 1991, during the First Persian Gulf War, Iraqi ZSU-57-2s shot down a British Tornado GR1 strike aircraft during an attack by four British Tornados on the Iraqi Shaibah air base. The same day in the late evening one more Tornado GR1 was shot down and three British Tornados were heavily damaged by AA artillery fire near Shaibah. ZSU-57-2s were also used in combats during the 2003 Invasion of Iraq.
ZSU-57-2s saw service during the Yugoslav Wars, usually in light batteries used for attacking ground targets. They were used during the Croatian War of Independence when Croatian forces captured 2 ZSU-57-2s from the JNA. ZSU-57-2s were used in the air defense role in 1999 during the NATO air raids against Yugoslavia when the Serbs operated 54 of these vehicles.