BT-7 (Bystrochodnij Tankov)

History

In the second half of the 1920s, the Soviet Army began modernizing its aging tank fleet. So it held a relatively open competition for its design office to find the right combination of weapons, speed and armor protection, using the best aspects of existing tanks from around the world. One of the most famous designs is the M1931 light tank, designed by American J. Walter Christie (1865-1944), a racing mechanic, inventor and mechanical engineer. The M1931 uses its world-renowned "Christie" suspension system, which employs torsion bars to provide a high degree of flexibility at above-average speeds. Therefore, it excels in creating "light" or "fast" armor systems.

While the development of his Christie suspension is often overlooked in the US, it rose to prominence elsewhere in the world when the British, French and Russians all took notice. Christie tried unsuccessfully to sell his M1931 "Christie Tank" to the US Army.

Between 1930 and 1931, Russia received two Christie M1931 prototypes (without turrets and weapons) for evaluation (these prototypes were sent under forged documents claiming they were farm tractors and not main battle tanks). Using existing designs for the Russians had some advantages, as they proved to be a less costly engineering endeavor in the long run. After testing, the Russians liked what they saw in Christie and redesigned this type of BT ("Bystrokhodnij Tankov" or "Fast Tank") light tank for their own teams. Subsequently, the government obtained a license to mass-produce the Christie design.

The original production versions - the BT-1 and BT-2 - were essentially direct copies of Christie's designs, and of the two, only the BT-2 was the first to be modified in the Soviet style. The series eventually evolved into subtle changes to simplify production, and was powered by an engine originally intended for use in aircraft. The BT-2 prototype was completed in October 1931 and production began the following year. The main armament is centered around a 37mm main gun, but the lack of armament means some are pure machine gun tanks.

Subsequent BT-5 models were subsequently upgraded with a 45mm main gun armament. Regardless, the pair produced a fast and maneuverable tank that resulted in the final BT-7 model in 1935, with a new turret, new gearbox, heavier armor, and a more powerful engine.

Operational service for the BT-7 began in 1937 under the official designation BT-7-1 - these turrets were identified by their cylindrical turret design, which was later upgraded to a more conical shape.

Overall, the BT-7 design demonstrates great off-road capability and equally great on-road speed thanks to the Christie suspension. The suspension is attached to eight large wheels, four of which are located on one side of the track, each mounted independently.

To take advantage of the BT-7's adaptability for off-road operations, tracks of different widths can be adjusted as needed to provide varying degrees of traction on different types of terrain. The BT-7 is designed so that crews can completely remove the tracks in 30 minutes to be able to drive the tank on the road with its own wheels, the "drive" is now on the rear sprocket The rear wheels are relocated, while the front wheels are used for steering . However, this feature proved to be a new thing, barely used in practice, and was eventually removed from later BT series models. The idea behind this driving mode is to give the tank excellent wheel speed from point A to point B, but this really only works when driving on the road. In a country with limited paved roads, it makes little sense to preserve this characteristic for future forms of production.

Furthermore, the orbital removal process is said to be cumbersome and complicated for practical use.

Despite being lightly armored, the BT-7 was well-armed, as it had a 45mm main gun in a circular pivot turret, putting it on par with many other contemporaneous turrets. The main armament is also supported by a 7.62mm universal anti-personnel machine gun in the turret as a coaxially mounted weapon. Typically, tanks carry 172 to 188x45mm projectiles and 2,394 rounds of 7.62mm ammunition.

Some BT-7 models were also equipped with an additional 7.62mm machine gun mounted on a trainable tee at the rear of the turret to protect the rear of the tank from direct infantry attack. Over time, the equipment became somewhat useless when tanks were paired with infantry squads.

Infantry squads can now protect BT-7s from direct melee attacks from the enemy.

Early production forms of the BT-7 had a riveted turret structure, which added another layer of danger to the crew. If hit directly by enemy shells, the rivets securing the BT-7 turret armor represent bullet-like projectiles inside the turret capable of causing serious damage to the crew, ammunition and critical systems. As a result, production inevitably turned to welded turret systems.

In practice, the BT-7 proved to be a reliable and robust mechanical fighter, respected by the crew for its performance and ease of maintenance at the time.

Visually, the BT-7 retains most of Christie's original appearance. It comes with an easily recognizable sloping glass panel that spans the track's fenders. The sides of the hull superstructure also have a nice slope, which helps in part to provide awkward angles for incoming enemy shells. The hull is of fully welded construction. The driver sits in the center of the front of the fuselage, and the entry/exit hatch shows a simple forward-looking slot.

Directly behind the driver is a movable turret with the main gun. The BT-7 is operated by a crew of three, including a driver in the fuselage and two operators in the turret.

The BT-7 weighs only 13.5 tons and is powered by a 450 hp M-17 V12 diesel engine. This enables speeds of over 32 mph and a range of up to 217 miles. All fairings have armor thicknesses ranging from 6 to 22 mm, providing modest protection at the expense of speed.

The BT-7 is 18 feet 7 inches long and 7 feet 11 inches tall.

The BT-7 chassis is ideal for making branch designs such as the BT-7A close support artillery tank, which mounts a short-barreled 76.2mm gun. The 76.2mm gun quickly proved to be the gun of choice when fighting heavy German tanks and became the standard weapon for the upcoming and highly successful T-34 series of medium tanks. In addition to this variant, the BT-7 was developed into a command tank called the BT-7-I(U), which added communications equipment at the expense of increased ammunition. Offenses rely on these vehicles to facilitate clear communication and leadership between tanks on the battlefield.

The BT-7M (or BT-8) was later produced as an improved BT-7 form with a 500 hp V2 twelve-cylinder diesel engine in a modified hull for increased survivability. In addition to its 76.2mm main gun armament, the BT-7M is armed with a pair of 7.62mm self-defense machine guns - one in the turret and the other in the fuselage.

Experimental versions included bridge and amphibious models that never went into production.

Given that the previous BT-5s had proven useful in the Spanish Civil War, it was logical to expect them to be successful when the BT-7s were heavily used during the Soviet invasion of Poland. The tank became the main armored vehicle led by the Red Army in this operation.

Poland was inevitably conquered jointly by the Germans in the west and the Soviets in the east, with little help from the Allies.

However, the future of the BT-7 was called into question during the Winter War with Finland and the follow-up to the German invasion of the Soviet Union. The anti-tank weapons deployed by the Finns caused many casualties to the BT-7 units.

By the time of the German invasion (as part of Operation Barbarossa) in 1941, the BT-7 was in full service, with a limited number of them available, but basically peaked in terms of effectiveness. Although it had already "modernized" the Soviet armored units a few years ago, it soon became apparent that this type had significant shortcomings when fighting the new generation of German tanks, especially with regard to armor protection. As expected, casualties from underarmed and lightly armored systems increased rapidly.

Combine these inherent limitations with well-trained commanders and aircrews and poorly maintained vehicles, and you can devise a recipe for disaster on the battlefield. After all, the BT-7 is a light tank at its core and was never really intended to melee a medium or heavy tank in any way. If anything, light tank designs are expected to provide armored reconnaissance or infantry support in well-planned engagements. However, as a direct attack aircraft, the BT-7 is noticeably lacking in key areas of protection and offensive performance.

By the end of 1941, a large number of BT-7s were either shot down by the enemy or retired through logistical support. All specimens captured by the Germans were reconstructed for security purposes only, to cover the rear of Soviet flanking maneuvers, not as front-line tools.

In any case, the surprised Russians used everything they had at the time to finally avoid extinction at the hands of the Germans. The German offensive was eventually slowed and stopped, only to be repelled by determined and sometimes suicidal resistance from the Soviet Union. Although it was obsolete by the summer of 1941, the BT-7 undoubtedly played a role in the reconstruction of the Soviet Union and incorporated its achievements into the design of the future winning T-34 medium tank. In 1937, a new group of Soviet talent came together to find a planned successor to the BT series.

The group provided what would eventually become the T-34 itself.

With the BT-7's role in the West almost complete, Soviet authorities transferred the tanks to operations against the Japanese along the Russian border during the Soviet invasion of Manchuria in August 1945. After an agreement with the Allies at the Tehran conference in November 1943, Soviet troops redeployed three months before the end of the war in Europe. In these missions, the BT-7 proved far superior to any armored infantry vehicle Japan could deploy. This will be the last recorded combat action for all BT tanks whose legacy has been secured in history.

The Soviet invasion of Manchuria was the largest operation of the Soviet-Japanese War of 1945, the end result of which was the liberation of Manchukuo (Manchuria) by the Russians. The Soviet Union's landslide victory here played a role in the final surrender of Imperial Japan to end World War II.

Nearly 5,000 BT-7 prototypes were eventually produced, making up a large portion of the entire 8,500-strong BT Series family.

Specification

Basic

Roles

Dimensions

Performance

Performance

for everyone else in our database)

Armor

172 to 188 x 45mm bullets

2,394x7.62mm ammo

Changes