ZSU-57-2 (Ob'yekt 500) Russian 57mm Self-Propelled Anti-Aircraft Gun

Hezbollah Proliferation. The ZSU-57-2 Ob'yekt 500 is a Soviet self-propelled anti-aircraft gun (SPAAG), armed with two 57 mm autocannons. 'ZSU' stands for Zenitnaya Samokhodnaya Ustanovka, meaning "anti-aircraft self-propelled mount", '57' stands for the bore of the armament in millimeters 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 "twin mount", referring to the twin autocannon with which the vehicle is armed. Based 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 much thinner armor. The vehicle was armed with twin 57 mm S-68 autocannon in a new, large, rotating, open-topped turret. The ZSU-57-2 comprises three compartments: driver's in the front, fighting in the middle, and engine transmission at the rear. The hull is more spacious than the T-54 because of the thinner armor and has different locations for some equipment. The general layout, with the transverse mounting of the engine, is the same The driver's compartment is located on the left-hand side of the front of the hull. The driver's seat is moved forward and to the left compared to its location in the T-54. The compartment has a single-piece hatch cover opening to the left and two periscopic vision devices. One of them can be replaced by the TVN-1 infrared vision device, which operates together with the infrared headlamp (active night vision), which is mounted on the right track board. A fire-fighting equipment signal panel and a spare parts case are also located in the driver's compartment.