KV-90

Although the KV-1’s armor and 76.2mm gun proved formidable during the tank’s initial battles in 1941, the Soviet military also explored other options as part of its heavy tank doctrine, largely in response to Germany’s rapid refinement of its large-caliber guns and development of its own heavy tanks, including the Tiger I. One development path led to work on super-heavy tank concepts, such as the KV-4, which featured robust armor and large-caliber guns that could serve to break through enemy defenses. The events of World War II often curtailed work on such projects.