KV-4

The KV-4 (Object 224; ) was a proposed Soviet heavy break-through tank, developed during World War II as a part of the Kliment Voroshilov tank design series.

==Design history== In early 1941, Soviet intelligence reported on the production of new German heavy tanks. Prior to the start of Operation Barbarossa, the main heavy tank in service in the Red Army was the KV-1, which armour was, at the time, impenetrable by any tank-mounted weapon then in service. However, this new report caused alarm within the Soviet high command, and thus they decided to work on the design of a new heavy tank destined to counter the new threat.