The KW-1 is a Soviet heavy tank from the Second World War. The first  prototypes of this vehicle were made in 1939, and the car entered  service a year later (1940). Approximately 4,700-5,000 vehicles of this  type were produced in the course of production. The combat weight of the tank was up to 42.5 tons. The drive was provided by a single W-2K  diesel engine with a power of up to 600 HP. The main armament consisted  of a 76.2 mm ZiS-5 gun and three 7.62 mm DT machineguns.

 The KW-1 vehicle was developed as a successor to the failed T-35 tank.  Compared to its predecessor, it differed on many levels, and above all,  the multi-turret system was abandoned in favor of a single turret with  main armament. What's more, based on the experience of the civil war in  Spain (1936-1939), the armor of the entire car was also very impressive, for the late 1930s. Finally, when it was introduced to the KW-1 line,  it clearly exceeded the armor and firepower of virtually every German  tank. However, it was not without disadvantages, including poor  maneuverability and high failure rate of some mechanical elements -  especially the drive train. The KW-1 was used on a large scale during  the German-Soviet war of 1941-1945, and its serial production was  maintained until 1943 in parallel with the production of the T-34. The  variants of the KW-1 include the KW-1s (a vehicle with improved  reliability and ergonomics) and the KW-85 (armed with a 85mm D-5T gun).