Comparing: IS-3A vs. FCM 50 t

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.

Development was started in December 1945. The vehicle was conceived as an alternative for the AMX 50t and combined archaic features typical of the pre-war French tank-construction industry as well as German innovations. The vehicle was to be equipped with an additional container trailer, equipment for underwater driving, and a demountable mine clearer.