Although outclassed later in the war, it was considered one of the more successful and widely produced tank model in the 1930s. It, along with the BT light tanks, composed of the majority of Russia's armoured forces in late 1930s. It weighed just a little under 10 tons, had 15 mm thick armour in front, with a 45 mm 20K gun, and had a crew of three people. The Bolshevik Factory in Leningrad was the first factory to start producing the T-26 from June 1931, and production of the tank lasted from then until 1941.