KV-3 Heavy Tank

With the KV-1 and KV-2 heavy tanks in production, Soviet planners turned their minds to even more powerful tanks. On 17 June 1940, they ordered the Kirov plant to produce four prototypes by December 1940.

Only two were produced: the T-150, a KV-1 with heavier armor, and the T-220, a larger vehicle with even thicker armor and an 85mm gun. Testing revealed major flaws with both designs.

The T-150 was underpowered, and the new engine on the T-220 blew up on the second day of testing! Despite of this, the T-150 was ordered into production as the KV-3 in March 1941. Rumors of a massive German heavy tank, and the realities of producing what was in effect an even more unreliable KV-1 tank, quickly changed the order to produce the T-220 tank with a new engine and an even bigger 107mm gun.

This new design was to be ready in just six weeks, along with a production plan for over 500 to be built by the end of 1941.

The new KV-3 was fitted with a supercharged version of the V-2 tank engine, straight off the drawing boards. This time it worked, and with strengthened suspension and transmission, the tank had completed 1985km (1233 miles) by 22 June. At this point affairs were interrupted by the German invasion.

Within weeks the Kirov factory was threatened and evacuated to Chelyabinsk in the Urals and ordered to focus on producing existing KV-1 types to rebuild the Red Army after the disasters that had occurred at the start of the German invasion.

The KV-3 is perhaps the most balanced and powerful heavy tank in existence. It combines an outstanding gun with thick armor and reasonable speed. It is the perfect Tiger killer, yet it entered combat six months before the German Tiger heavy tank.