planes by a "Groza" stabilizer. Object 279 carried 24 rounds of ammunition, with charge and the shell to be loaded separately. The gun was provided with a semi-automatic loading system with a rate of fire of 5–7 rounds/minute. Firing control system comprised optical rangefinder, auto-guidance system and L2 night-sight with an active infrared searchlight. An improved variant of the gun was later tested on the experimental tank Object 785 in the late 1970s. History One of the reasons that this tank project was abandoned, as with other heavy tank projects, was that the Soviet military ceased to operate such heavy fighting vehicles in 1960. Since then, the heaviest ones are kept at about 50 metric tons of weight, not counting extra equipment such as additional reactive armor or mine clearing devices. On July 22, 1960, at the demonstration of new technology on the range of Kapustin Yar, Nikita Khrushchev strictly forbade any tanks with a weight of more than 37 metric tons to be adopted by the military, having thus written off the entire program of heavy tanks that had proven to be so successful. Adding to this decision was that Nikita Khrushchev himself was a supporter of an alternative – guided missile tanks, the most prominent of which was IT-1. Furthermore, the Soviet military wanted tanks with a suitable weight for crossing their own bridges, in case of homeland defence situations similar to those that occurred during World War II, which at that time seemed to be unreliable for heavy vehicle crossings. Another reason was that a number of serious deficiencies of the running gear appeared during the trials. These deficiencies included low nimbleness, efficiency loss during swampy area crossings, complex and expensive production, maintenance and repair, and impossibility of reduction in the overall height of the tank. Surviving vehicles : One example of the tank survives on display at the Kubinka Tank Museum, and was restored to running condition in 2022. References Cold War tanks of the Soviet Union Heavy tanks of the Cold War Trial and research tanks of the Soviet Union Abandoned military projects of the Soviet Union Heavy tanks of the Soviet Union History of the tank Kirov Plant products