Comparing: IS-5 (Object 730) vs. IS-3A

The development of the vehicle was started in 1949 by the Design Bureau of the Chelyabinsk Kirov Plant under the supervision of Joseph Kotin. In 1950 a preproduction batch of 10 vehicles was launched. After the vehicle underwent all trials and received upgrades, it was adopted for service in 1953 under the designation IS-8.

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.