PT-1A light amphibious tank. Source: bronetehnika.narod.ru
Work on the PT-1 began when the Red Army’s Department of Mechanization and Motorization developed a tactical and technical specification for a medium amphibious tank with a combat weight of up to 20 tonnes. It was to be armed with a 45 mm gun and three machine guns, and crewed by six people. The tank needed to have a maximum speed of 30 km/h on the road and be armored to withstand 37 mm shells at a distance of over 1 km. In August 1930, the specification was sent to the Izhora and Bolshevik plants for further consideration. Based on this, the Technical Department of the Economic Management under the Joint State Political Department developed a project for the amphibious tank PT-1 with a convertible drive.
