Design on the KV-1 heavy tank began in 1938, with the intention that it should be the successor to the T-35 heavy tank. The first models of the KV-1 were field-tested during the Red Army's disastrous 1940 campaign in Finland. Despite the military setback, the KV-1 set the standard for Soviet tank design for several years to come, regularly used to spearhead breakthroughs or accompany infantry on the assault. While it was certainly a formidable vehicle, the KV-1 was not particularly mobile, routinely suffering from a number of automotive problems. It was also uparmored progressively without any concomittant changes made to the power plant, which resulted in a poor power-to-weight ratio and continual degradation in performance. Nevertheless, many historians view the KV series as an important achievement for the Russian military-industrial complex because it paved the way for more successful designs, including the "Josef Stalin" tanks. Sold Out!