The Spanish Civil War demonstrated the need for much heavier armour on tanks, and was the main influence on Soviet tank design just prior to World War II.

The T-35 conformed to the 1920s notion of a 'breakthrough tank' with very heavy firepower though its armour protection was lacking and it suffered from poor mobility. KV-1 with KV-1S turret in the Great Patriotic War Museum, Moscow.Īfter disappointing results with the multi-turreted T-35 heavy tank, Soviet tank designers started drawing up replacements. Later in the war, the KV series became a base for the development of the IS (Iosif Stalin) series of tanks and self-propelled guns. In fact the only advantage the KV had over the T-34/76 was its larger and roomier three-man turret. As the war progressed, it became evident that there was little sense in producing the expensive KV tanks, as the T-34 medium tank performed better (or at least equally well) in all practical respects. Prior to the start of Operation Barbarossa in June 1941, about 500 of the over 22,000 tanks then in Soviet service were of the KV-1 type. Until the Germans developed more effective guns, the KV-1 was invulnerable to almost any German weapon except the 8.8 cm Flak gun. The KV tanks were practically immune to the 3.7 cm KwK 36 and howitzer-like, short-barreled 7.5 cm KwK 37 guns mounted, respectively, on the early Panzer III and Panzer IV tanks fielded by the invading German forces.

The German Wehrmacht at that time rarely deployed its tanks against KVs, as their own armament was too poor to deal with the ' Russischer Koloss' – 'Russian Colossus'. In certain situations, even a single KV-1 or KV-2 supported by infantry could halt German formations. The KV tanks were known for their heavy armour protection during the early stages of the war, especially during the first year of the German invasion of the Soviet Union. The Kliment Voroshilov ( KV) tanks are a series of Soviet heavy tanks named after the Soviet defence commissar and politician Kliment Voroshilov who operated with the Red Army during World War II.

Dt dog launcher