BT-7M (BT-8 / A-8) Light Wheeled-and-tracked Tank
The BT-7 tank was developed at the Kharkov Locomotive Works in 1934. This tank was based on the BT-5 light wheel-track tank. Its hull shape was changed and armor protection was improved. The BT-7M (sometimes the name BT-8 or A-8 is found) light tank is the last production version of the BT tank family. It was derived from the BT-7 in autumn 1936 and differed from the baseline model in its 500 hp V-2 diesel engine. At that time the BT-7M was the fastest tank in the world. Its speed reached 62 km/h on tracks and 86 km/h on wheels. The tank was in serial production during 1939 and 1940. Tanks of this type participated in combat at the early stage of the Great Patriotic War.
In 1938, four experimental samples of a BT-8 tank with a B-2 diesel engine were manufactured at the Kharkov Locomotive Plant - it was necessary to optimize fuel consumption. After comparative tests of BT-7 and BT-8, it was decided to launch into the production of tanks with a diesel engine. At the end of 1939, the production of the BT-7M tank began, which was a modified version of the BT-7, from which it almost did not look different. Armament also remained the same.
Externally, the BT-7M practically did not differ from its predecessor, the BT-7. The main difference is the replacement of the M-17T carburetor engine with the Soviet diesel V-2. Due to the installation of braces, the rigidity of the tank hull increased, and the frontal armoring had to be strengthened. The dimensions of the air filter were reduced, and there was a sub-engine hatch in the bottom. The V-2 diesel engine consumed much less fuel than the aircraft engine used previously on the BT-7. This motor efficiency made it possible to abandon additional fuel tanks that were located on the fences on the BT-7.
The serial production of the BT-7M began in December 1939. The tank was a version of the BT-7 tank fitted with a V-2 diesel engine. The vehicle design was re-developed to enable the V-2 diesel to be incorporated and operated. The purpose of installation of a diesel engine in the tank consisted in improving the fuel efficiency of the power pack, in increasing the vehicle's fuel distance as well as in reducing fire risk when operating the tank or when the tank is hit on the battlefield. The tank was put into series production and accepted for service with the Red Army, taking part in the Second World War. Total production of the BT-7M was 790 vehicles.
The most important difference is that diesel-powered tanks were significantly safer in combat, since diesel fuel ignites worse when a tank is damaged. It should be noted that by this time the Japanese serial tanks "Ha-Go" and tanks "Type 86" were already equipped with diesel engines. In 1935, they began to produce tanks with diesel engines and in Poland - this is the 7TR tank. Significant success was achieved by the French, but did not go into a series of cars with diesel engines. In Germany, tank diesel engines were not even developed, since it was believed that with the start of hostilities, there would be problems with the production of diesel fuel.
A total of 788 BT-7M were built. BT-7M light tanks were mass-produced until September 1940, even in parallel with the new T-34. Subsequently, all production facilities of the plant were transferred to the production of T-34.
|Year of manufacture of the first vehicle||1939|
|- length||5,660 mm|
|- width||2,290 mm|
|-main gun||45 mm|
|- 2 machine guns||7.62 mm|
|Engine power output||400 hp|
|Maximum road speed:|
|- on tracks||62 km/h|
|-on wheels||86 km/h|
|-on tracks||400 km|
|- on wheels||700 km|
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