In 1957 the Kirov Plant in Leningrad started an ultra-heavy tank under designer Troyanov. His design, Object 279, was radically unorthodox as it was meant to survive a nearby tactical nuke explosion! As such it was weighted down by a cast turret with guard ring, an armored elliptical shield, and a 4-track system in two pairs to balance all that weight. The hull was also bow-shaped like a boat with heavy uneven pieces designed to hold the tank down when the shockwave hit!!! The main gun was a 130mm M-65 firing APDS rounds. It had a crew of 4 with secondary armament of a 14.5mm KPVT MG and featured a fire control system that used optical and radar rangefinders for targeting. It had a N-2 night sight with IR searchlight. It's 1000 hp 2DG-8M engine allowed the beast to cross rough terrain of all sorts and also anti-tank obstacles up to 3 ft. It had an NBC compartment and also heating and cooling which was rare in the 1950s. It went through trials in the late 50s but was cancelled in 1959 by Khrushchev and the Kremlin that felt ultra-heavy tanks died out with the German Maus (188-203 tons)!!! The sole survivor sits in the Kubinka armor museum near Moscow. Object 279 was designed for WW3 projected for the 1960s, but that never came...

*UHT= Ultra-Heavy Tank: http://www.militaryfactory.com/armor/imgs/object-279.jpg