Main Menu

Soviet Union's BT-7¹ Bystrochodnij Tankov (Fast Tank)

BT-7 Fast Tank crashed:	BT-7 Fast Tank in Moscow in 1938:	BT-7A Fast Tank in the Ukraine in 1941:
BT-7 Fast Tank:	BT-7 Fast Tank:	BT-7-1 Fast Tank:	BT-7-1 Fast Tank:
BT-7-1(V) Fast Tank:	BT-7-1(V) Fast Tank:	BT-7-1(V) Fast Tank:	BT-7-2 Fast Tank:
BT-7-2 Fast Tank:	BT-7-2 Fast Tank:	BT-7-2 Fast Tank:	BT-7-2 Fast Tank:
BT-7-2 Fast Tank:	BT-7-2 Fast Tank:	BT-7-2 Fast Tank:	BT-7-2 Fast Tank training turret:
BT-7-2 Fast Tank training turret at the Stalin Military Academy:	BT-7 Model 1935 Fast Tank, 8th Mechanized Corps.	BT-7A Fast Tank:	BT-7A Fast Tank:
Early model BT-7 fast tank:	Early model BT-7 fast tank:	Late model BT-7 Fast Tank: Imperial War Museum	Late model BT-7 Fast Tank:
BT-7M Fast Tank:

Design

After seeing that tanks with riveted construction were vulnerable it was decided to produce a welded tank.¹

In September 1936, during maneuvers in Byelorussia, British General Wavell and Colonel Martel saw the tank.⁷ Martel wrote: "The design of the fighting body is not very good but the performance of the machine is at least twice as good as the A9."⁷ He further suggested that the British War Office purchase one.⁷

Had new Saslavsky brakes, new main clutch, new turret¹, thicker armor¹, and all welded^1,10.²

Main Armament

The main gun was the 45 mm model 1934 / 45 mm Model 35¹ tank gun.²

In 1938 an improved gun sighting system, called TOS, was installed.^2,11 This was developed by V. A. Pavlov and A. Z. Tumanov.¹¹ The main armament could now better fire on the move.¹¹

Engine

The engine was a copy of a German BMW aircraft engine.¹

New engine with an improved gearbox with 3 forward gears.^2,10 Used a control stick for steering.²

Turret

The first turrets for the BT-7 were the same cylindrical turret that was used on the BT-5.² A conical turret was then used with MG in rear.^1,2,10 It had round hatches on top which led to the nickname "Mickey Mouse" from German troops.²

Prototype

Production

BT-7: 2,000
- Production: 1935 - ?^2,7,11
BT-7M¹, BT-8¹: ~700¹, 706²
- Production: 1938 - 1940, 1939 - 1941²
BT-IS¹: 1¹

Variants

BT-7¹: Had a better engine than previous BT models.² The gearbox provided 3 forward gears.²
BT-7-1: Cylindrical turret from the BT-5.^7,11 Hull a new electro-welded hull.¹¹ Armor was thicker.¹¹ The transmission was improved and the fuel capacity was increased.¹¹ The tracks were smaller pitch.¹¹
BT-7-2^1,11, BT-7 Ob. 1937¹¹: Conical turret with twin horn periscopes.^1,7,11 Had 2 round hatches on the turret room and was nicknamed "Mickey Mouse" by the Germans.² Hull armored was redesinged.¹¹ All vehicles had radios.¹¹
BT-7-1(U), BT-7TU¹, BT-7(V)¹, BT-7-1(V)¹⁰: Command tank.^1,10 Carried 132-146 shells². Had a 71-TK radio set installed. The cylindrical turrets had a wrap around antenna, whereas the conical turrets had a rod antenna.²
OP-7^1,2: Flame thrower installed in left side / right side¹ of hull.² Weighed 11.5 tons.² Apparently didn't reach the front lines.
BT-7A^1,11: Artillery tank.^1,2,11 Had short barreled 76.2 mm gun installed.^1,2,11 Carried 40 shells if it had a radio, and 50¹ if it didn't.² Turret was modified from a T-28.¹¹ Because of the increased weight it was no longer able to move on wheels.¹¹
BT-7M^1,10,11, BT-8^1,7,11: Was a major redesign in 1939. It had a sloping front glacis instead of the previous pointed noses.⁷ Had a diesel engine installed.^10,11 The engine was based on a Hispano-Suiza 12Y aircraft engine.¹ Hull MG was placed next to the driver.⁷ Used at Khalkin-Gol and in Finland.⁷
BT-7U¹¹, BT-7TU¹¹: Radio installed.¹¹
BT-8A²: Artillery tank.² Had 76.2 mm 1927/32 tank gun.² Only a test model built.²
BT-IS¹: Prototype only.¹ Used BT-7M hull.¹ Used a BT-7 turret with 45 mm gun.¹

Usage

Used by the 2nd Mechanized Brigade at Lake Hasan against the Japanese in 1938.⁹ The 6th and 11th Tank Brigades had 400 BT-7s and BT-5s, and fought against the Japanese at the Khalkin Gol River from May to August 1939.^2,9

Used during the invasion of Poland in 1939 and in Finland in 1939-1940.^1,2,7

	BT-7¹ (1936 model)	BT-7-1¹¹	BT-7-1V	BT-7-2	BT-7A^1,11	BT-7M¹ (1939 model), BT-8¹	BT-IS¹
Crew	3^1,2,3,4,5,10	3^8,11	3⁸	3^8,11	3^8,11	3^2,8,11	3^1,8
Physical Characteristics
Weight	30,450 lb 13.68 tons¹, 13.7 tons¹⁰, 13.8 tons^2,4,6, 14 tons⁵ 13,900 kg^1,10	13.8 tons^8,11	13.6 tons⁸	13.68 tons¹, 13.8 tons^8,11 13,900 kg¹	13.8 tons^8,11	32,300 lb, 14.4 tons¹, 14.4-14.5 tons², 14.6 tons⁷, 14.65 tons^2,8,11 14,650 kg¹	15.35 tons¹, 15.6 tons⁸ 15,600 kg¹
Length w/gun	18', 18' 7"^1,10, 18' 8"^3,7, 18.65'⁴, 20' 0.5" 5.68 m³, 5.66 m^1,2,5,6,10, 6.8 m⁵	18.65^8,11	18.65⁸	18.65'^8,11, 18' 7"¹ 5.66 m¹	18'¹¹, 18.65⁸	18.65'^8,11, 20'¹, 20' 0.5" 5.66 m², 6.11 m¹	18' 11"¹, 18.98'⁸ 5.76 m¹
Length w/o gun
Height	7' 6"^3,7, 7.5'⁴, 7' 11"^1,10, 7' 11.3"⁵, 8' 7" 2.28 m³, 2.41 m¹⁰, 2.42 m^1,2,5,6	7.5'^8,11	7.5'⁸	7.5'^8,11, 7' 11"¹ 2.42 m¹	7.5'^8,11	7.5'^8,11, 8'¹, 8' 0.75", 2.42 m², 2.46 m¹	7' 6"^1,8 2.28 m¹
Width	7'³, , 7' 6"^1,5, 7' 11.5"¹⁰, 7.98'⁴, 8'⁷, 8' 7" 2.23 m⁶, 2.29 m^1,2,5, 2.43 m^3,10	7.98^8,11	7.98⁸	7' 6"¹, 7.98'^8,11 2.29 m¹	7.98^8,11	7.98'^8,11, 8' 7", 2.29 m²	7' 6"^1,8 2.28 m¹
Width over tracks
Ground clearance	1' 2", 4-4.2 m²	Wheels: 10.5"⁸ Tracks: 12"⁸	Wheels: 10.5"⁸ Tracks: 12"⁸	Wheels: 10.5"⁸ Tracks: 12"⁸	12"⁸	0.35 m² Wheels: 10.5"⁸ Tracks: 12"⁸	Wheels: 10.5"⁸ Tracks: 12"⁸
Ground contact length		12'^8,11	12'⁸	12'^8,11	12'⁸, 12' 6"¹¹	12'^8,11	12'⁸
Ground pressure	11.24 psi, 0.75 kp/cm² ²	10.2 psi⁸	10.2 psi⁸	10.2 psi⁸	10.2 psi⁸	10.4 psi⁸ 0.78 kp/cm² ²	11 psi⁸
Turret ring diameter
Armament
Main	45 mm^4,5,10 45 mm M-32³ 45 mm 1934² 45 mm 1934 L/46, 45 mm¹ 45 mm Model 35¹	45 mm L/46⁸ 45 mm L/46 A/TK¹¹	45 mm L/46⁸	45 mm L/46⁸ 45 mm L/46 A/TK¹¹	76.2 mm L/16.5^8,11 76.2 mm¹	45 mm Model 38¹ 76.2 mm⁵ 76.2 mm² 76.2 mm L/26^8,11	45 mm¹ 45 mm L/46⁸
OR						45 mm 1938²
Secondary
MG	2: MG⁴ 2: 7.62 mm DT MG^3,10 2: 7.62 mm MG^1,5	2: 7.62 mm MG¹¹ 2: 7.62 mm DTMG⁸	2: 7.62 mm DTMG⁸	2: 7.62 mm MG¹¹ 2: 7.62 mm DTMG⁸	2: 7.62 mm MG¹¹ 7.62 mm DTMG⁸	2: 7.62 mm MG¹¹	2: 7.62 mm DTMG⁸
MG - coaxial	7.62 mm MG²					7.62 mm DT MG²
MG - rear turret						7.62 mm DT MG²
MG - hull	7.62 mm MG²					7.62 mm DT MG²
Side arms
Quantity
Main	132 - 188², 146¹	172⁸, 172 - 188¹¹	188⁸	132 - 146¹¹ With radio: 146⁸ Without radio: 188⁸	50¹, 132⁸, 172 - 188¹¹	40^8,11	132⁸
Secondary
MG	2,394²	2,394^8,11	2,394⁸	2,394^8,11	2,394^8,11	2,394^2,11	2,394⁸
Side arms
Armor Thickness (mm)	10 - 22⁵, 6 - 22^3,4, 22^7,10 Turret: 15⁷ Front: 20⁶ Side: 15⁶	15 - 20¹¹		6 - 22¹			30¹
Hull Front, Upper	13- 22, 22²	22^8,11	22⁸	22^8,11	22^8,11	22^2,8,11, 30	30⁸
Hull Front, Lower	13, 22²					22²
Hull Sides, Upper	13²	13^8,11	13⁸	13^8,11	13^8,11	13^2,8,11	15⁸
Hull Sides, Lower	13²					13²
Hull Rear	13²	13⁸	13⁸	13⁸	13⁸	6 - 10¹¹, 13^2,8	13⁸
Hull Top	10²	6 - 10^8,11	6 - 10⁸	6 - 10^8,11	6 - 10^8,11	6 - 10^8,11, 10²	6 - 10⁸
Hull Bottom	12, 6-10²	6 - 10^8,11	6 - 10⁸	6 - 10^8,11	6 - 10^8,11	6-10^2,8,11	6 - 10⁸
Turret Front	15²	10 - 13¹¹, 13⁸	13⁸	10 - 13¹¹, 15⁸	10 - 13¹¹, 15⁸	10 - 15¹¹, 15^2,8	30⁸
Turret Sides	15²	13⁸	13⁸	15⁸	15⁸	15^2,8	20⁸
Turret Rear	15²	13⁸	13⁸	15⁸	15⁸	15^2,8	15⁸
Turret Top	10, 15²	10⁸	10⁸	10⁸	10⁸	10⁸, 15²	10⁸
Engine (Make / Model)	M-15 T^2,3,10 M-17T^2,5,7	M-17T Liberty¹¹ MT-17T Liberty modified Aero⁸	MT-17T Liberty modified Aero⁸	M-17T Liberty¹¹ MT-17T Liberty modified Aero⁸ M17-TV-12¹	M-17T Liberty¹¹, MT-17T Liberty modified Aero⁸	W-2² V-2^8,11	M17-T-V-12¹ V-2⁸
Bore / stroke	4 stroke²	120 mm⁸ / 146 mm⁸	120 mm⁸ / 146 mm⁸	120 mm⁸ / 146 mm⁸	120 mm⁸ / 146 mm⁸	150 mm⁸ / 187.7 mm⁸ 4 stroke²	150 mm⁸ / 187.7 mm⁸
Cooling		Water⁸	Water⁸	Water⁸	Water⁸	Water^1,8	Water⁸
Cylinders	12², V-12^5,10	12¹¹, V-12⁸	V-12⁸	12¹¹, V-12⁸	12¹¹, V-12⁸	12¹¹, V-12^1,2,8	V-12⁸
Capacity
Net HP	450^4,6,7,10, 405@1,750 rpm², 500⁵	450¹¹, 450@1,750 rpm⁸	450@1,750 rpm⁸	450¹¹, 450@1,750 rpm⁸, 500@1,760 rpm¹	450¹¹, 450@1,750 rpm⁸	500^2,11, 500@2,200 rpm⁸	500¹, 500@2,200 rpm⁸
Power to weight ratio	32.6 hp/ton²	32.6 hp/ton⁸	32.6 hp/ton⁸	32.6 hp/ton⁸	32.6 hp/ton⁸	34.7 hp/ton², 35 hp/ton⁸	32 hp/ton⁸
Compression ratio
Transmission (Type)	3 forward, 1 reverse²	Wheels: Chain drive⁸ Tracks: Sliding gear⁸	Wheels: Chain drive⁸ Tracks: Sliding gear⁸	Wheels: Chain drive⁸ Tracks: Sliding gear⁸	Wheels: Chain drive⁸ Tracks: Sliding gear⁸	Wheels: Chain drive⁸ Tracks: Sliding gear⁸	Wheels: Chain drive⁸ Tracks: Sliding gear⁸
Steering
Steering ratio
Starter
Electrical system
Ignition
Fuel (Type)	Gasoline^4,5,10	Gasoline^8,11	Gasoline⁸	Gasoline^8,11	Gasoline^8,11	Diesel^1,8,11	Diesel⁸
Octane
Quantity	167 gallons, 790 liters²	174 gallons⁸	174 gallons⁸	174 gallons⁸	174 gallons⁸	174 gallons⁸	174 gallons⁸
Road consumption
Cross country consumption
Performance
Traverse	360°	360°⁸	360°⁸	360°⁸	360°⁸	360°	360°⁸
Max speed	53.4 mph^3,5, 46 mph, 45 mph^1,4 50 kph⁶, 72 kph¹, 86 kph^3,5	46 mph¹¹		45 mph¹, 46 mph¹¹ 72 kph¹	40 mph⁸, 46 mph¹¹	40 mph, 53.4 mph¹, 54 mph¹¹ 86 kph¹	40 mph¹ 65 kph¹
Max speed - tracks	33 mph⁷, 45 mph¹⁰ 53 kph², 72 kph¹⁰					62 kpm²
Max speed - wheels	45 mph⁷, 70 mph¹⁰, 73 kph², 112 kph¹⁰	45.6 mph⁸	45.6 mph⁸	45.6 mph⁸		54 mph⁸ 86 kph²	70 mph⁸
Cross country speed	31 mph			31 mph¹ 50 kph¹	33 mph⁸	31 mph¹, 39 mph⁸ 50 kph¹
Cross country speed - tracks		33 mph⁸	33 mph⁸	33 mph⁸			40 mph⁸
Road radius	155 miles^3,5, 311 miles, 265 miles¹ 250 km^3,5, 430 km¹	310 miles¹¹		265 miles¹, 310 miles¹¹ 430 km¹	280 miles⁸, 310 miles¹¹	435 miles, 440 miles¹¹	250 miles¹ 400 km¹
Road radius - tracks	249 miles¹⁰, 375 km², 400 km¹⁰					600 km²
Road radius - wheels	311 miles¹⁰, 500 km^2,10	310 miles⁸	310 miles⁸	310 miles⁸		440 miles⁸, 700 km²	430 miles⁸
Cross country radius		220 miles¹¹		220 miles¹¹	220 miles^8,11	375 miles¹¹
Cross country radius - tracks		220 miles⁸	220 miles⁸	220 miles⁸		375 miles⁸	370 miles⁸
Turning radius	20' 6"	40'⁸	40'⁸	40'⁸	40'⁸	40'⁸	40'⁸
Elevation limits		-4° to +40°⁸	-4° to +40°⁸	-4° to +40°⁸	-4° to +60°⁸	-10° to +40°⁸	-10° to +40°⁸
Fording depth	4'⁵ 1.2 m², 1.22 m⁵	3.98'⁸	3.98'⁸	3.98'⁸	3.98'⁸	3.25'⁸ 1.2 m²	3.25'⁸
Trench crossing	6'⁵, 6' 7", 1.83 m⁵, 2 m²	6'⁸	6'⁸	6'⁸	6'⁸	6.85'⁸ 2 m²	6.85'⁸
Vertical obstacle	1' 10", 2' 6"⁵, 0.55 m², 0.76 m⁵	Wheels: 8"⁸ Tracks: 30"⁸	Wheels: 8"⁸ Tracks: 30"⁸	Wheels: 8"⁸ Tracks: 30"⁸	30"⁸	0.55 m² Wheels: 8"⁸ Tracks: 30⁸	Wheels: 8"⁸ Tracks: 30"⁸
Climbing ability	32°²					32°²
Suspension (Type)	Christie	Christie Independent type⁸	Christie Independent type⁸	Christie Independent type⁸	Christie Independent type⁸		Christie Independent type⁸
Wheels each side	4	4⁸	4⁸	4⁸	4⁸		4⁸
Return rollers each side
Tracks (Type)
Length
Width	10"
Width - tire		2 x 3.95"⁸	2 x 3.95"⁸	2 x 3.95"⁸	2 x 3.95"⁸	2 x 3.95"⁸	2 x 3.95"⁸
Width - track		10.25"^8,11	10.25"⁸	10.25"^8,11	10.25"^8,11	10.25"^8,11	10.25"⁸
Diameter		32.5"⁸	32.5"⁸	32.5"⁸	32.5"⁸	32.5"⁸	32.5"⁸
Number of links
Pitch
Tire tread
Track centers/tread		6.33'⁸	6.33'⁸	6.33'⁸	6.33'⁸	6.33⁸	6.33'⁸

Sources:

Russian Tanks of World War II Stalin's Armored Might, by Tim Bean & Will Fowler, 2002
Russian Tanks and Armored Vehicles 1917-1945, by Wolfgang Fleischer, 1999
The Encyclopedia of Tanks and Armored Fighting Vehicles - The Comprehensive Guide to Over 900 Armored Fighting Vehicles From 1915 to the Present Day, General Editor: Christopher F. Foss, 2002
Tanks of the World, 1915-1945, Peter Chamberlain, Chris Ellis, 1972
The Encyclopedia of Weapons of World War II, Chris Bishop, 1998
Jane's World War II Tanks and Fighting Vehicles The Complete Guide, Leland Ness, 2002
Tanks of World War II, Duncan Crow, 1979
Profile AFV Weapons 37 Russian BT Series, John F. Milsom, 1971
Russian Armour Volume 2: Light Tank T-27, T-38, BT, T-26, T-40, T-50, T-60, T-70, Mikhail Baryatinskiy, 2006
The Illustrated Guide to Tanks of the World, George Forty, 2006
Airfix Magazine Guide 22 Russian Tanks of World War 2, John Milsom and Steve Zaloga, 1977