ZSU - 37 ZSU - 37 was a Soviet - made , light , self - propelled anti - aircraft gun ( SPAAG ) , developed by the end of 1943 and produced at Works No . 40 in Mytishchi . It was the first Soviet series - produced tracked SPAAG . ZSU stands for Zenitnaya Samokhodnaya Ustanovka ( ) , meaning " anti - aircraft self - propelled mount " . History . Soviet engineers carried out some early experiments with tracked SPAAGs before and during World War II , including a modification of the T - 70 light tank , resulting in the experimental T - 90 SPAAG which was armed with two 12 . 7 mm DShKT heavy machine gun s ( the prototype was built in November 1942 by GAZ ) . The T - 70 light tank would eventually be further developed into the SU - 76 light self - propelled gun chassis , which in turn was to become the base for the ZSU - 37 SPAAG . It was decided to use the chassis of the SU - 76M in order to speed up and cheapen the production of the much needed tracked and armoured SPAAGs . The ZSU - 37 was produced from March 1945 to 1948 , and 75 vehicles were built in total ( only a few vehicles were produced before the war ended , due to temporary manufacturing technology ) . As a result of its late production and the almost non - appearance of the few remaining " Luftwaffe " aircraft in the spring of 1945 , the ZSU - 37 saw no service in World War II . An experimental self - propelled anti - aircraft artillery battalion equipped with 12 ZSU - 37 SPAAGs was formed by the end of 1945 . After World War II it became clear that the low rate of fire and firepower of a single 37 mm AA gun was not effective against high - speed low altitude targets . The anti - aircraft artillery crews found it difficult to manually track fast - moving targets . SPAAGs based on a light tank chassis also had quite low manœuvrability in difficult terrain and low off - road speed and range in comparison with medium tanks and self - propelled guns ( SPG ) s , which the ZSU - 37 was meant to protect . The two tandem engines used on the SU - 76M chassis required gasoline fuel , which was sometimes a problem in tank units equipped with diesel - engined tanks . The ZSU - 37 was retired from service because of the aforementioned reasons soon after series production was stopped . An effort was made to significantly increase the firepower by mounting the same 37 mm gun into a quad - mount on a T - 34 medium tank chassis , but the vehicle never left the design stage as it was recommended by the Technical Council of the Ministry of Transport to use a newer tank chassis and the more powerful S - 68 57 mm twin anti - aircraft autocannon , which was being developed at the time . The next step in Soviet tracked SPAAG technology would come with the ZSU - 57 - 2 , which was based on the T - 54 medium tank chassis and was mass - produced in 1957 - 1960 . The ZSU - 37 - 2 " Yenisei " is a later , unrelated design based on the chassis of the experimental SU - 100P self - propelled gun . It was armed with a twin - 37 mm 500P " Angara " anti - aircraft autocannon . The development of completely new radar - guided SPAAG vehicles , namely the ZSU - 37 - 2 and the ZSU - 23 - 4 began in 1957 . The promising ZSU - 37 - 2 " Yenisei " competed with the ZSU - 23 - 4 " Shilka " as the replacement for the ZSU - 57 - 2 SPAAG but the planned series production of the " Yenisei " was rejected in 1962 in favour of the production of the " Shilka " . Description . The ZSU - 37 SPAAG , which was based on the chassis of the SU - 76M was equipped with an open - top turret and armed with one 37 mm 61 - K mod . 1939 anti - aircraft autocannon . The vehicle was equipped with an automatic sight of the distance - type with two collimators , a stereo range finder with a 1 - meter base , a 12RT - 3 radio , a TPU - 3F intercom system and mechanical aiming mechanisms with two rates of angular motion for adequate speed and smoothness of aiming ( the traverse mechanism had a foot switch of rates ) . The crew consisted of six men : a driver , an aimer for azimuth , an aimer for elevation , a sight adjuster for target speed and range , a sight adjuster for target course and dive angle , and a loader . The ZSU - 37 was based on the SU - 76M because it also shared its technical drawbacks and advantages , the most discussed of which was the open - top turret . To protect the crew from rain and snow the gun compartment could be covered with tarpaulin , however the gun could not be fully elevated when this was done . The open turret had advantages , such as high elevation angle , excellent visibility for the gunners and no need for ventilation . Light and manoeuvrable , the ZSU - 37 was considered quite an effective SPAAG in the mid - 1940s . However , it had insufficient off - road capabilities to accompany medium and heavy tanks in difficult terrain . Ammunition consisted of 320 armour - piercing , fragmentation incendiary and fragmentation rounds ( all with tracer s ) . 130 rounds were in 5 - round cartridges and 190 rounds were without cartridges . Armour - piercing composite rounds could be used against enemy heavy tank s . Muzzle velocity was between 890 and 920 m / s depending on projectile type , the armour - piercing shell weighed 0 . 785 kg , fragmentation shells weighed 0 . 732 kg . The autocannon could be depressed and elevated manually between - 5° and + 85° . Cyclic rate of fire was 120 to 130 rounds per minute while the practical rate of fire was about 50 to 60 rounds per minute . Maximum combat vertical fire was 2 , 500 m while the maximum vertical range was 6 , 500 m . The vehicle could cross 0 . 67 m high vertical obstacles , 2 m wide trenches , ford 0 . 9 m deep water obstacles and climb 25° gradients . Transmission and undercarriage were identical to those of the SU - 76M SPG . The engine was also the same but forced from 140 hp on SU - 76M to 160 hp - a GAZ - 203 which consisted of two tandem GAZ - 202 6 - cylinder row liquid - cooled gasoline engines , each producing 80 hp ( 63 kWt ) at 3600 rpm . Preservation status . The experimental SU - 11 vehicle is on display at the Kubinka Tank Museum in Russia .