BT-7
Encyclopedia
The BT-7 was the last of the BT tank series of Soviet
cavalry tanks that were produced in large numbers between 1935 and 1940. They were lightly armoured, but reasonably well-armed for their time, and had much better mobility than other contemporary tank designs. The BT tanks were known by the nickname Betka from the acronym, or its diminutive Betushka.
The successor of the BT-7 Tank would be the famous T-34
medium tank, introduced in 1940, which would replace all of the Soviet fast tanks, infantry tanks, and medium tanks then in service.
BT stands for fast tank .
The first prototypes of the BT-7 had a distinctive canted-ellipse shaped turret mounting both the main gun and a coaxial machine-gun. The specification also called for the project to allow for installation without any significant change to the framework of new guns: the 76 mm KT-26 or PS-3 main gun (a short-barreled howitzer) and the 45 mm 20K model 1932/38, a long-barreled, high-velocity gun useful against tanks, but less effective than the 76 mm gun against infantry.
In the rear of the turret there was housed a rotating drum-type magazine for 18 76 mm shells or a radio station. The prototype underwent an extensive testing program in the summer and autumn of 1934. As a result of this testing, it was felt that a machine-gun was unnecessary on a tank with a 3-man crew, especially as it made the assembly of the turret more complicated.
Therefore, in early 1935, the tank went into production with a simpler design, incorporating the turret from the BT-5. (However, the idea of wheeled/tracked vehicle with a 76 mm cannon was not abandoned and the plant was commissioned to develop a new BT-7 turret from the turret of the T-26
-4.) In the production model, a cylindrical turret housed a 45 mm 20K gun with a DT-model machine-gun. On some of the tanks, a model 71-TC radio with frame antenna was installed.
The crew consisted of three men: the commander (who also served as the gunner); the loader and the driver. In 1937 the company launched production of the BT-7 with a conical turret. Main armament remained the same, but the ammunition was increased to 44 rounds. All serving tanks now installed the DT machine gun in the rear niche. For the firing of the gun and coaxial machine gun at night, the tank was equipped with two special projector-type headlamps, and a mask placed on the gun. Subsequently, these lights were retrofitted to earlier models of the tank. Improvements were also made to the drive wheels, caterpillar tracks and gearbox by 1938.
In parallel with the main modification, 154 BT-7A artillery tanks were produced between 1936 and 1938, fitted with a larger turret and a 76 mm KT-type gun, 50 rounds of ammunition (40 in a tank with a portable radio).
In 1938, four experimental BT-8 tanks mounted with V-2 diesel engines
were produced. After comparative tests of the BT-7 and BT-8, the diesel tanks were put into production in 1940 (under the designation BT-7M) with the powerplants being produced in a separate plant of the Voroshilovets factory to ensure supply. From December 1939, the BT-7A went into production with some minor modifications - additional bracing for rigidity, a manhole underneath, and a smaller air filter. The diesel tanks showed much-reduced fuel costs, and the petrol tanks were soon placed into reserve.
In November 1939, the Table of Organization and Equipment for a Soviet light tank brigade included the following units:
Several experimental tanks were conceived based on the BT series, for example the wheeled BT-IS, designed by N.F. Tsyganov, a platoon commander in the 4th Armoured Regiment of the Ukraine Military District and self-taught designer. The type successfully passed field tests but was not ordered in bulk. Another Tsyganov design was the S-2 "Cherepaha" (turtle, черепаха) , with a new design of hull and turret. There was also the command tank KBT-7 with a fixed turret, the OT-7 mounting a flamethrower
, the KhBT-7 designed to protect from toxic contamination and lay smokescreens, the SBT bridgelayer and the TTBT-7 and Thubten-7 radio-controlled tanks (known at the time as Teletanks). Finland converted 18 captured tanks into BT-42
assault guns.
Shortly before Operation Barbarossa
, the BT-7 underwent an up-armour programme. In 1940, Mariupol Ilyich Iron and Steel Works produced 50 sets of hinged homogeneous armor for the BT-7M, which increased the weight of the test tank to 18 tons. On the installation of these kits to military units, unfortunately, nothing is known.
Between 1935 and 1940, between 2700 and 5328 BT-7 tanks of all modifications (except BT-7A) were built. They were operated by the armored and mechanized forces of the Red Army for almost the entire war. Over 2000 BT-7 series tanks were lost in the first 12 months on the Eastern Front
. Hundreds had been immobilized even before the invasion by poor maintenance, and had to be abandoned as all Soviet forces withdrew eastward. The survivors fought against the Wehrmacht
in numbers gradually reduced by attrition
, until superseded by more modern types in 1944. The BT-7 series continued in use elsewhere, including being used against Japanese forces (Battle of Khalkhyn Gol and Manchurian Strategic Offensive Operation) in Manchuria
in 1945.
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
cavalry tanks that were produced in large numbers between 1935 and 1940. They were lightly armoured, but reasonably well-armed for their time, and had much better mobility than other contemporary tank designs. The BT tanks were known by the nickname Betka from the acronym, or its diminutive Betushka.
The successor of the BT-7 Tank would be the famous T-34
T-34
The T-34 was a Soviet medium tank produced from 1940 to 1958. Although its armour and armament were surpassed by later tanks of the era, it has been often credited as the most effective, efficient and influential design of World War II...
medium tank, introduced in 1940, which would replace all of the Soviet fast tanks, infantry tanks, and medium tanks then in service.
BT stands for fast tank .
Development
In the rear of the turret there was housed a rotating drum-type magazine for 18 76 mm shells or a radio station. The prototype underwent an extensive testing program in the summer and autumn of 1934. As a result of this testing, it was felt that a machine-gun was unnecessary on a tank with a 3-man crew, especially as it made the assembly of the turret more complicated.
Therefore, in early 1935, the tank went into production with a simpler design, incorporating the turret from the BT-5. (However, the idea of wheeled/tracked vehicle with a 76 mm cannon was not abandoned and the plant was commissioned to develop a new BT-7 turret from the turret of the T-26
T-26
The T-26 tank was a Soviet light infantry tank used during many conflicts of the 1930s as well as during World War II. It was a development of the British Vickers 6-Ton tank and is widely considered one of the most successful tank designs of the 1930s....
-4.) In the production model, a cylindrical turret housed a 45 mm 20K gun with a DT-model machine-gun. On some of the tanks, a model 71-TC radio with frame antenna was installed.
The crew consisted of three men: the commander (who also served as the gunner); the loader and the driver. In 1937 the company launched production of the BT-7 with a conical turret. Main armament remained the same, but the ammunition was increased to 44 rounds. All serving tanks now installed the DT machine gun in the rear niche. For the firing of the gun and coaxial machine gun at night, the tank was equipped with two special projector-type headlamps, and a mask placed on the gun. Subsequently, these lights were retrofitted to earlier models of the tank. Improvements were also made to the drive wheels, caterpillar tracks and gearbox by 1938.
In parallel with the main modification, 154 BT-7A artillery tanks were produced between 1936 and 1938, fitted with a larger turret and a 76 mm KT-type gun, 50 rounds of ammunition (40 in a tank with a portable radio).
In 1938, four experimental BT-8 tanks mounted with V-2 diesel engines
Diesel model V-2
The Diesel model V-2 was a twelve-cylinder Soviet tank engine found on the T-10, T-34 and Kliment Voroshilov tanks....
were produced. After comparative tests of the BT-7 and BT-8, the diesel tanks were put into production in 1940 (under the designation BT-7M) with the powerplants being produced in a separate plant of the Voroshilovets factory to ensure supply. From December 1939, the BT-7A went into production with some minor modifications - additional bracing for rigidity, a manhole underneath, and a smaller air filter. The diesel tanks showed much-reduced fuel costs, and the petrol tanks were soon placed into reserve.
In November 1939, the Table of Organization and Equipment for a Soviet light tank brigade included the following units:
- 3 tank battalions, each containing
- 3 tank companies, each with 17 BT-7 or T-26 tanks;
- 1 signal platoon;
- 1 antitank platoon with 3 45 mm antitank guns;
- 1 antiaircraft machine gunMachine gunA machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
(AA MG) platoon - 1 reserve tank company, with 8 BT-7 or T-26 tanks;
- 1 signal company, with 5 T-37 tanks;
- 1 motorized infantry battalion, containing
- 3 motorized rifle companies;
- 1 signal platoon;
- 1 antitank platoon with 3 45 mm antitank guns;
- 1 AA MG platoon
- 1 additional AA MG platoon in brigade headquarters;
- 1 motor transport battalion;
- 1 reconnaissance battalion;
- 1 pioneer company;
- 1 medical company;
- 1 chemical company.
Flamethrower
A flamethrower is a mechanical device designed to project a long controllable stream of fire.Some flamethrowers project a stream of ignited flammable liquid; some project a long gas flame. Most military flamethrowers use liquids, but commercial flamethrowers tend to use high-pressure propane and...
, the KhBT-7 designed to protect from toxic contamination and lay smokescreens, the SBT bridgelayer and the TTBT-7 and Thubten-7 radio-controlled tanks (known at the time as Teletanks). Finland converted 18 captured tanks into BT-42
BT-42
The BT-42 was a Finnish assault gun, constructed during the Continuation War. It was constructed from captured Soviet BT-7 light tanks and British 4.5-inch howitzers from 1918, which had been donated during the Winter War...
assault guns.
Shortly before Operation Barbarossa
Operation Barbarossa
Operation Barbarossa was the code name for Germany's invasion of the Soviet Union during World War II that began on 22 June 1941. Over 4.5 million troops of the Axis powers invaded the USSR along a front., the largest invasion in the history of warfare...
, the BT-7 underwent an up-armour programme. In 1940, Mariupol Ilyich Iron and Steel Works produced 50 sets of hinged homogeneous armor for the BT-7M, which increased the weight of the test tank to 18 tons. On the installation of these kits to military units, unfortunately, nothing is known.
Between 1935 and 1940, between 2700 and 5328 BT-7 tanks of all modifications (except BT-7A) were built. They were operated by the armored and mechanized forces of the Red Army for almost the entire war. Over 2000 BT-7 series tanks were lost in the first 12 months on the Eastern Front
Eastern Front (World War II)
The Eastern Front of World War II was a theatre of World War II between the European Axis powers and co-belligerent Finland against the Soviet Union, Poland, and some other Allies which encompassed Northern, Southern and Eastern Europe from 22 June 1941 to 9 May 1945...
. Hundreds had been immobilized even before the invasion by poor maintenance, and had to be abandoned as all Soviet forces withdrew eastward. The survivors fought against the Wehrmacht
Wehrmacht
The Wehrmacht – from , to defend and , the might/power) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the Heer , the Kriegsmarine and the Luftwaffe .-Origin and use of the term:...
in numbers gradually reduced by attrition
Attrition warfare
Attrition warfare is a military strategy in which a belligerent side attempts to win a war by wearing down its enemy to the point of collapse through continuous losses in personnel and matériel....
, until superseded by more modern types in 1944. The BT-7 series continued in use elsewhere, including being used against Japanese forces (Battle of Khalkhyn Gol and Manchurian Strategic Offensive Operation) in Manchuria
Manchuria
Manchuria is a historical name given to a large geographic region in northeast Asia. Depending on the definition of its extent, Manchuria usually falls entirely within the People's Republic of China, or is sometimes divided between China and Russia. The region is commonly referred to as Northeast...
in 1945.