KV-1

The KV-1 is a Soviet heavy tank, the lead vehicle of the KV family named after Soviet defense commissar Kliment Voroshilov, which entered service in 1939 and remained in production through 1943. Weighing around 45 tons, mounting a 76.2mm main gun and powered by a 600 horsepower diesel engine, the KV-1 was distinguished above all by armor that German anti-tank guns of the early war years struggled to penetrate, and accounts from the 1941 German invasion of the Soviet Union describe individual KV-1 tanks, supported by infantry, holding up entire German formations largely immune to the standard German anti-tank weapons available at the time. German troops reportedly nicknamed the type the Russian Colossus in recognition of this early-war armor advantage, and although the KV-1's thick armor came at the cost of mobility and reliability compared with the lighter and faster T-34, it played an important role in blunting the initial German advance before the Soviet Union shifted its heavy tank production toward the improved IS series.