page_title: BT tank
section_title: Variants
hierarchical_section_title: BT tank / Variants
context_page_description: The BT tanks were a series of Soviet light tanks produced in large numbers between 1932 and 1941. They were lightly armoured, but reasonably well-armed for their time, and had the best mobility of all contemporary tanks. The BT tanks were known by the nickname Betka from the acronym, or its diminutive Betushka. The successor of the BT tanks was the famous T-34 medium tank, introduced in 1940, which would replace all of the Soviet fast tanks, infantry tanks, and medium tanks in service.
context_section_description: Soviet Union variants:
  BT-1: Christie prototype with no turret
  BT-2 Model 1932: M-5-400 engine (copy of U.S. Liberty engine); three turret versions were produced: with single 37mm gun; 37mm gun and one DT machine gun; twin DP machine guns mount and a single machine gun. In late 1932, modified to BT-3 but produced under the same designation.
  BT-2-IS
  BT-3: same as BT-2, produced according to metric system (instead of the Imperial system as used for the BT-2). In official documentation referred to as BT-2.
  BT-4: was a design with welded hull and minor changes in the suspension. Three prototypes produced (with partially riveted hulls).
  BT-5: larger cylindrical turret, 45 mm 20-K gun, coaxial DT machine gun
  BT-5 Model 1933: new turret with twin hatches and larger bustle
  BT-5PKh: snorkelling variant (prototypes only)
  BT-5A: artillery support version with 76.2 mm howitzer (few made)
  RBT-5: rocket launcher artillery version, equipped with two 420 mm tank torpedoes (prototypes only)
  BT-5 flamethrower tank: (prototypes only)
  BT-5-IS: experimental model with heavily sloped front armor, it served as "sloped armor testbed" together with the BT-SW-2 experimental tank
  PT-1A: amphibious variant with new hull (few made)
  TT-BT-5: teletank, remote-radio-controlled tank
  BT-7 Model 1935: welded hull, redesigned hull front, new Mikulin M-17T engine (licensed copy of a BMW engine), enclosed muffler
  BT-7 Model 1937: new turret with sloping armour
  BT-7TU: command version, with whip antenna instead of earlier frame antenna
  BT-7A: artillery support version with a 76.2 mm howitzer; a 7.62 mm DT machine gun was on the turret rear. 155 were made. Some had the howitzer replaced with the longer 76.2 mm/31.5 caliber F-32 gun, testing that weapon before its implementation on the KV-1 heavy tank.
  OP-7: flame-thrower version with external fuel panniers (prototype only)
  TT-BT-7: teletank, remote-radio-controlled tank
  BT-SV-2 Cherepakha ("turtle"): another prototype, this took armour sloping to an extreme
  BT-7-IS
  BT-7M (1938, prototypes designated A-8; sometimes referred to as BT-8): new V-2 diesel engine replacing earlier gasoline engines, three DT machine guns: coaxial, in P-40 AA mount on roof and in a ball-mount on turret rear.
  A-20 (also known as BT-20): prototype for a new BT tank, with 20mm extremely sloped armour inspired by BT-SV-2 prototype, 45mm 20-K gun, model V-2 diesel engine. Lost out in trials to the tracked-only A-32. The only built prototype is known to have participated in the Battle of Moscow. In 1941, as the Germans neared Moscow, the situation was so desperate that everything battle-worthy was put into service by the Soviets. The A-20 prototype, which at that time was at Kubinka army proving ground near Moscow for evaluation trials, was immediately put into service together with other prototypes of tanks present here, which were organized into a separate company led by Captain Semenov. Later on, the tank was included in the 22nd Tank Brigade organic, together with its predecessors and successors, BT-7 and T-34 tanks. On December 1, 1941, during fighting, the tank was seriously damaged and sent to the rear for repairs. Three days later, it re-entered service with the 22nd Tank Brigade until mid-December, when the tank was again damaged and evacuated to the rear. After these events, its fate is unknown.
   A-32 (A-20G): initially known as the A-20G (G - tracked) and then renamed to A-32, it was the competitor to the A-20. The wheels-and-tracks system was removed for the first time from the BT tanks series, making the tank design and production easier, more reliable and, especially, lighter; in fact, armor was increased to 30mm, hull was enlarged, 5th road wheel was fitted in for better ground-pressure distribution and the 45mm 20-K gun was replaced by the 76.2mm L-10 gun, but the weight increased by only 1 ton (from 18 to 19 tons, respectively for the A-20 and A-32). Trials in 1939 showed that the tank armor could be upgraded and thus a request for increase to 45mm was made. A second prototype was specially created for the purpose, this tim
caption: BT-7A artillery support tank was a self-propelled gun variant, armed with a 76.2 mm howitzer