T-54/T-55

T-54/55
A T-55 tank on display at the Imperial War Museum
Type	Medium tank (Warsaw Pact designation) Main battle tank (NATO designation)
Place of origin	Soviet Union
Service history
In service	1948–present
Used by	See Operators
Wars	See Service History
Production history
Designer	KMDB (T-54) OKB-520 (T-54A and later)
Designed	1945–1958
Manufacturer	KhPZ, UVZ (Soviet Union) Bumar-Łabędy (Poland) ZTS Martin (Czechoslovakia)
Unit cost	US$200,000 (export price to Egypt, 1956–1972)[1]
Produced	1946–1981 (Soviet Union) 1956–1979 (Poland) 1957–1983 (Czechoslovakia)
No. built	96,500–100,000+ est., including: More than 35,000 T-54 and More than 27,500 T-55 (by Soviet Union) 13,000 Type-59/69/79 (by China) 11,000 T-54/55 (by Czechoslovakia) 10,000 T-54/55 (by Poland)
Variants	See Operators and variants section below
Specifications (T-55)
Mass	36 metric tons (35.4 long tons; 39.7 short tons)
Length	9.00 m (29 ft 6 in) with gun forward
Width	3.37 m (11 ft 1 in)
Height	2.40 m (7 ft 10 in)
Crew	4
Armour	205 mm turret front 130 mm turret sides 60 mm turret rear 30 mm turret roof 120 mm hull front at 60° (100 mm after 1949)[2] 79 mm hull upper sides 20 mm hull lower sides 60 mm at 0° hull rear 20 mm hull bottom 33–16 mm hull roof
Main armament	D-10T 100 mm rifled gun (43 rounds)
Secondary armament	7.62 mm SGMT coaxial machine gun, (12.7 mm DShK heavy machine gun)
Engine	Model V-55(V-54) V-12 water-cooled. 38.88-litre diesel 500 horsepower (373 kW) up to 800 horsepower (600 kW) (late versions)
Power/weight	14.6 horsepower per metric ton (10.9 kW/t)
Transmission	Mechanical (synchromesh), 5 forward, 1 reverse gears
Suspension	Torsion bar
Ground clearance	0.425 m (16.7 in)
Fuel capacity	580 L internal, 320 L external (less on early T54), 400 L jettisonable rear drums
Operational range	325 kilometres (202 mi), 610 kilometres (380 mi) with extra tanks (on unpaved roads)
Maximum speed	51 kilometres per hour (32 mph)

The T-54 and T-55 tanks are a series of Soviet medium tanks^[3] introduced in the years following the Second World War. The first T-54 prototype was completed at Nizhny Tagil by the end of 1945.^[4] From the late 1950s, the T-54 eventually became the main tank for armoured units of the Soviet Army, armies of the Warsaw Pact countries, and many others. T-54s and T-55s have been involved in many of the world's armed conflicts since their introduction in the second half of the 20th century.

The T-54/55 series is the most-produced tank in history. Estimated production numbers for the series range from 96,500 to 100,000. They were replaced by the T-62, T-64, T-72, T-80 and T-90 tanks in the Soviet and Russian armies, but remain in use by up to 50 other armies worldwide, some having received sophisticated retrofitting. The Chinese version of the T-54A is the Type 59.

During the Cold War, Soviet tanks never directly faced their NATO adversaries in European combat. However, the T-54/55's first appearance in the West around the period of the 1950s (then the beginning of the Cold War) spurred the United Kingdom to develop a new tank gun, the Royal Ordnance L7, and the United States to create the M60 tank.^[5]