BT Fast Tank
Быстроходный танк (БТ), Bystrokhodny tank, light. "fast tank" or "high-speed" tank was a series of Soviet cavalry tanks
Based on the Christie prototypes and plans, BT-2 entered production in 1932.
BT tanks were "convertible tanks." This was a feature designed by J. Walter Christie to reduce wear on the tracks of the 1930s. In about thirty minutes the crew could remove the tracks and engage a chain drive to the rear most road wheel on each side, allowing the tank to travel at very high speeds on roads. In wheeled mode the tank was steered by pivoting the front road wheels. However, Soviet tank forces soon found the convertible option of little practical use in a country with few paved roads, and it consumed space and added needless complexity and weight.
The BT tank design served as a platform for experimentation with artillery support tanks and advanced armor layout, and further development led directly its successor the T-34.
Prototypes were completed in October 1931 and mass production began in 1932
BT-5 Model 1933
Designed in 1933 , this variant had a new turret with twin hatches and larger bustle.
BT tanks saw service in the Spanish Civil War, Battle of Khalkhin Gol / Nomonhan Incident, the Winter War in Finland, the Polish campaign, and in the early and last days of World War II.
Produced in large numbers between 1932 and 1941. Models included BT-2, BT-5, BT-7, BT-7A and BT-7M.
A total of 2,108 BT-5 tanks were built.