Main Menu

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

BT-7 Fast Tank crashed:
Soviet Union's BT-7 Fast Tanks crashed
BT-7 Fast Tank in Moscow in 1938:
Soviet Union's BT-7 Fast Tank in Moscow in 1938
BT-7A Fast Tank in the Ukraine in 1941:
Soviet Union's BT-7A Fast Tank in the Ukraine in 1941
 
BT-7 Fast Tank:
Soviet Union's BT-7 Fast Tank
BT-7 Fast Tank:
Soviet Union's BT-7 Fast Tank
BT-7-1 Fast Tank:
Soviet Union's BT-7-1 Fast Tank
BT-7-1 Fast Tank:
Soviet Union's BT-7-1 Fast Tank
BT-7-1(V) Fast Tank:
Soviet Union's BT-7-1(v) Fast Tank
BT-7-1(V) Fast Tank:
Soviet Union's BT-7-1(v) Fast Tank
BT-7-1(V) Fast Tank:
Soviet Union's BT-7-1(v) Fast Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Fast Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Medium Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Medium Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Medium Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Medium Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Fast Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Fast Tank
BT-7-2 Fast Tank:
Soviet Union's BT-7-2 Fast Tank
BT-7-2 Fast Tank training turret:
Soviet Union's BT-7-2 Fast Tank training turret
BT-7-2 Fast Tank training turret at the Stalin Military Academy:
Soviet Union's BT-7-2 Fast Tank training turret at the Stalin Military Academy
BT-7 Model 1935 Fast Tank, 8th Mechanized Corps.
Russia's BT-7
BT-7A Fast Tank:
Soviet Union's BT-7A Fast Tank
BT-7A Fast Tank:
Soviet Union's BT-7A Fast Tank
Early model BT-7 fast tank:
Soviet Union's BT-7 Fast Tank
Early model BT-7 fast tank:
Soviet Union's BT-7 Fast Tank
Late model BT-7 Fast Tank:
Soviet Union's BT-7 Fast Tank, late model
Imperial War Museum
Late model BT-7 Fast Tank:
Soviet Union's BT-7 Fast Tank, late model
BT-7M Fast Tank:
Soviet Union's 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 welded1,10.2

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

Variants

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-7A1,11 BT-7M1 (1939 model), BT-81 BT-IS1
Crew 31,2,3,4,5,10 38,11 38 38,11 38,11 32,8,11 31,8
Physical Characteristics              
Weight 30,450 lb
13.68 tons1, 13.7 tons10, 13.8 tons2,4,6, 14 tons5
13,900 kg1,10
13.8 tons8,11 13.6 tons8 13.68 tons1, 13.8 tons8,11
13,900 kg1
13.8 tons8,11 32,300 lb,
14.4 tons1, 14.4-14.5 tons2, 14.6 tons7, 14.65 tons2,8,11
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 m1,2,5,6,10, 6.8 m5
18.658,11 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 m1,2,5,6
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 m1,2,5, 2.43 m3,10
7.988,11 7.988 7' 6"1, 7.98'8,11
2.29 m1
7.988,11 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 mm4,5,10
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/16.58,11
76.2 mm1
45 mm Model 381
76.2 mm5
76.2 mm2
76.2 mm L/268,11
45 mm1
45 mm L/468
OR           45 mm 19382  
Secondary              
MG 2: MG4
2: 7.62 mm DT MG3,10
2: 7.62 mm MG1,5
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 408,11 1328
Secondary              
MG 2,3942 2,3948,11 2,3948 2,3948,11 2,3948,11 2,3942,11 2,3948
Side arms              
Armor Thickness (mm) 10 - 225, 6 - 223,4, 227,10
Turret: 157
Front: 206
Side: 156
15 - 2011   6 - 221     301
Hull Front, Upper 13- 22, 222 228,11 228 228,11 228,11 222,8,11, 30 308
Hull Front, Lower 13, 222         222  
Hull Sides, Upper 132 138,11 138 138,11 138,11 132,8,11 158
Hull Sides, Lower 132         132  
Hull Rear 132 138 138 138 138 6 - 1011, 132,8 138
Hull Top 102 6 - 108,11 6 - 108 6 - 108,11 6 - 108,11 6 - 108,11, 102 6 - 108
Hull Bottom 12, 6-102 6 - 108,11 6 - 108 6 - 108,11 6 - 108,11 6-102,8,11 6 - 108
Turret Front 152 10 - 1311, 138 138 10 - 1311, 158 10 - 1311, 158 10 - 1511, 152,8 308
Turret Sides 152 138 138 158 158 152,8 208
Turret Rear 152 138 138 158 158 152,8 158
Turret Top 10, 152 108 108 108 108 108, 152 108
Engine (Make / Model) M-15 T2,3,10
M-17T2,5,7
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-28,11
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 Water1,8 Water8
Cylinders 122, V-125,10 1211, V-128 V-128 1211, V-128 1211, V-128 1211, V-121,2,8 V-128
Capacity              
Net HP 4504,6,7,10, 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 5002,11, 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) Gasoline4,5,10 Gasoline8,11 Gasoline8 Gasoline8,11 Gasoline8,11 Diesel1,8,11 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 mph3,5, 46 mph, 45 mph1,4
50 kph6, 72 kph1, 86 kph3,5
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 miles3,5, 311 miles, 265 miles1
250 km3,5, 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 km2,10 310 miles8 310 miles8 310 miles8   440 miles8, 700 km2 430 miles8
Cross country radius   220 miles11   220 miles11 220 miles8,11 375 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:

  1. Russian Tanks of World War II Stalin's Armored Might, by Tim Bean & Will Fowler, 2002
  2. Russian Tanks and Armored Vehicles 1917-1945, by Wolfgang Fleischer, 1999
  3. 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
  4. Tanks of the World, 1915-1945, Peter Chamberlain, Chris Ellis, 1972
  5. The Encyclopedia of Weapons of World War II, Chris Bishop, 1998
  6. Jane's World War II Tanks and Fighting Vehicles The Complete Guide, Leland Ness, 2002
  7. Tanks of World War II, Duncan Crow, 1979
  8. Profile AFV Weapons 37 Russian BT Series, John F. Milsom, 1971
  9. Russian Armour Volume 2: Light Tank T-27, T-38, BT, T-26, T-40, T-50, T-60, T-70, Mikhail Baryatinskiy, 2006
  10. The Illustrated Guide to Tanks of the World, George Forty, 2006
  11. Airfix Magazine Guide 22 Russian Tanks of World War 2, John Milsom and Steve Zaloga, 1977
Home page graphic for wwiivehicles.com, pictures of Sherman, T-34/85, Tiger, and Churchill