Comparing: IS-3A vs. VK 100.01 (P)

In 1956–1957, the Military Armored Forces Academy developed a speculative design for a new loading system on the IS-3 and T-10 heavy tanks. The IS-3 variant featured a double-row ammo rack with an automatic loading system. The crew was reduced to three members: commander, gunner, and driver. The turret was redesigned in order to accommodate the loading mechanism. The vehicle existed only in blueprints.

A version of the Maus from June 4, 1942. The 120-ton predecessor of the superheavy tank existed only in blueprints and never saw service. The vehicle was only an intermittent stage in the development of the Maus.