Comparing: Caernarvon vs. IS-3A

Development of this infantry support tank started in 1944. The first prototype was ready for trials in 1952. A total of 21 tanks were manufactured but never entered service. Some of the vehicles were later converted into the Conqueror heavy tanks.

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.