"T-54" redirects here. For an American tank prototype from the same era see T54 (American tank)
, and for other uses, see T54
"T55" redirects here. For the American utility carrier prototype see M50 Ontos
, and for the turbine engine, see Lycoming T55
Main battle tank
|Place of origin
OKB-520 (T-54A and later)
||KhPZ, UVZ (USSR),
ZTS Martin (Czechoslovakia)
||See Operators and variantssection below
||36 tonnes (39.7 ST)
||hull front 120, after 1949 100 mm @60°, turret front 205 mm (rounded), hull side 80 mm @0°, lower hull side 20 mm @0°, turret side 130 mm (rounded), hull rear 60 mm @0°, turret rear 60 mm (rounded), hull top 33–16 mm, turret top 30 mm, hull floor 20 mm
|D-10T 100 mm rifled gun
|7.62 mm SGMT coaxial machine gun, (12.7 mm DShKheavy machine gun)
||Model V-55(V-54) V-12 water-cooled. 38.88-l diesel
500 hp (373 kW) up to 800hp (597 kW) (late versions)
||Mechanical synchromesh, 5 forward, 1 reverse gears
||580 l internal, 320 l external (less on early T54), 400 l jettisonable rear drums
||48 km/h (30 mph)
The T-54 and T-55 tanks are a series of main battle tank introduced just as the Second World War ended. The first T-54 prototype appeared in March 1945 and entered full production in 1947. It 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 were involved in many of the world's armed conflicts during the late 20th and early 21st centuries.
The T-54/55 series eventually became the most-produced tank in history. Estimated production numbers for the series range from 86,000 to 100,000. They were replaced by the T-62, T-64, T-72, T-80, and T-90 in the Soviet and Russian armies, but remain in use by up to 50 other armies worldwide, some having received sophisticated retrofitting.
During the Cold War Soviet tanks never directly faced their NATO adversaries in Europe. However, the T-54/55's first appearance in the West in the 1950s spurred the United Kingdom to develop a new tank gun, the Royal Ordnance L7, and the United States to develop the M60 Patton.
Predecessors: T-34 and T-44
The Soviet T-34 medium tank of the 1940s is considered to have the best balance of firepower (F-34 tank gun 76.2 mm gun), protection and mobility for its cost of any tank of its time in the world. Its development never stopped throughout the Second World War and it continued to perform well; however, the designers could not incorporate the latest technologies or major developments as vital tank production could not be interrupted during wartime.
In 1943, the Morozov Design Bureau resurrected the pre-war T-34M development project and created the T-44 tank. Thanks to a space-efficient torsion-bar suspension, a novel transverse engine mount, and the removal of the hull machine-gunner's crew position, the T-44 had cross country performance at least as good as the T-34, but with substantially superior armour and a much more powerful 85 mm gun.
By the time the T-44 was ready for production, the T-34 had also been modified to fit the same gun. Although the T-44 was superior in most other ways, by this time T-34 production was in full swing and the massive numbers of T-34s being built offset any advantage to smaller numbers of a superior design. The T-44 was produced in only small numbers, around 2,000 being completed during the war. Instead, the designers continued to use the design as the basis for further improved guns, experimenting with a 122 mm design, but later deciding a 100 mm gun was a better alternative.
Efforts to fit the 100 mm gun to the T-44 demonstrated that small changes to the design would greatly improve the combination. The main issue was a larger turret ring, which suggested slightly enlarging the hull. A prototype of the new design, about 40 centimetres (16 in) longer and only 10 cm longer, was completed in 1945. This model looked almost identical to the original T-44, albeit with a much larger gun.
In testing there were numerous drawbacks, which required correction and many alterations that had to be made to the vehicle's design. It was decided to begin serial production of the new vehicle and the vehicle officially entered service on 29 April 1946. It would go into production in Nizhni Tagil in 1947 and Kharkiv in 1948.
T-55 front, rear and side elevations
Trials with nuclear weapons showed that a T-54 could survive a 2–15 kt nuclear charge at a range of more than 300 metres (980 ft) from the epicentre, but the crew only had a chance of surviving at 700 metres (2,300 ft). It was decided to create an NBC (nuclear, biological, and chemical) protection system which would start working 0.3 seconds after detecting gamma radiation.
The task of creating a basic PAZ (Protivoatomnaya Zashchita) NBC protection system offering protection against the blast of a nuclear explosion and (radioactive) particulate filtration, but not against external gamma radiation or gas, was given to the KB-60 design bureau in Kharkov and was completed in 1956. The documentation was sent to Uralvagonzavod. It was decided to increase the tank's battle capabilities by changing the tank's construction and introducing new production technologies. Many of those changes were initially tested on the T-54M (Ob'yekt 139). The tank was fitted with the new V-55 12-cylinder 4-stroke one-chamber 38.88 litre water-cooled diesel engine developing 581 hp (433 kW). Greater engine power was accomplished by increasing the pressure of the fuel delivery and charging degree. The designers planned to introduce a heating system for the engine compartment and MC-1 diesel fuel filter. The engine was to be started pneumatically with the use of an AK-150S charger and an electric starter. This eliminated the need for the tank to carry a tank filled with air. To allow easier access during maintenance and repairs, it was decided to change hatches over the engine compartment. To increase the operational range, 300 litres (66 imp gal; 79 US gal) fuel tanks were added to the front of the hull, increasing the overall fuel capacity to 680 litres (150 imp gal; 180 US gal).
The original T-55 lacked an antiaircraft machine gun mount.
The ammunition load for the main gun was increased from 34 to 45, with 18 shells stored in so called "wet containers" located in hull fuel tanks (the concept for which came from Kartsev's cancelled Ob'yekt 140). The ammunition load included high explosive-fragmentation and anti-tank rounds and designers also planned to introduce the BK5M HEAT rounds which penetrated 390 millimetres (15 in) thick armour. The TPKU commander's vision device was replaced by either the TPKUB or TPKU-2B. The gunner received a TNP-165 vision device. The loader's hatch-mounted 12.7 mm DShK anti-aircraft heavy machine gun was dropped, because it was deemed worthless against high-performance jets. The tank was supposed to be equipped with the "Rosa" fire protection system. The tank had a thicker turret casting and the improved two-plane gun stabilization system from the T-54B, as well as night vision fighting equipment. To balance the weight of the new equipment, the armour on the back of the hull was thinned slightly.
The T-55 was significantly superior to the IS-2 Heavy Tank in all respects, including the rate of fire of the gun (at least four compared to less than three rounds per minute). Despite somewhat thinner frontal turret armour (200 millimetres (7.9 in) instead of 250 millimetres (9.8 in)) it compared favourably with the IS-3, thanks to its improved antitank gun and better mobility. Heavy tanks soon fell from favour, with only 350 IS-3s produced. The old model of highly mobile medium tanks and heavily armoured heavy tanks was replaced by a new paradigm: the "main battle tank". Parallel developments in the West would produce similar results. Kartsev combined all the ongoing improvements being offered, or planned, on the T-54 into one design. This became the Ob'yect 155, and entered production at Uralvagonzavod 1 January 1958 as the T-55. It was accepted for service with the Red Army on 8 May. It suffered a significant lapse in one area: there was no antiaircraft machine gun, which had been present on the T-54.
After 1959, it served as a basis for the T-55K command tank which was equipped with an additional R-112 radio set, an AB-1-P/30 fuel powered accumulator charging unit, and TPN-1-22-11 night vision sight. All this additional equipment made it necessary to decrease the ammunition load for the main gun to 37 rounds and eliminate the bow machine gun. In the beginning of the 1960s, a T-55K was experimentally fitted with a Uran TV relay apparatus for battlefield surveillance. The tank was fitted with an external camera, the picture from which was relayed to a receiver in a BTR-50PU command vehicle. There was an observation camera mounted on a folding mast which was in turn mounted on a UAZ 69 car. The range within which the picture could be relayed varied between 10 and 30 kilometres (6.2 and 18.6 mi).
In 1961, a T-55 tank was used to test the "Almaz" TV complex which was supposed to replace the standard observation devices right after a nuclear explosion or while fording a body of water. There was a camera mounted on the hull for the driver and two cameras mounted on the turret, one for aiming and one for observation, and the picture from the cameras was relayed to two control screens. The tank had the front hull fuel tanks and bow machine gun removed. The commander was seated in the driver's usual position while the driver sat next to him. The cameras allowed battlefield observation and firing during daytime at ranges between 1.5 and 2 kilometres (0.93 and 1.24 mi). Because of the low quality of the equipment, the trials gave negative results. In the beginning of the 1960s, the OKB-29 design bureau in Omsk was working on adapting the tank to use a GTD-3T gas turbine engine developing 700 hp (522 kW). One T-55 tank fitted with this gas turbine engine passed trials but was deemed unsatisfactory and the design did not go into production.
The Omsk OKB-29 group tested three experimental T-55 tanks (designated Ob'yekt 612) between 1962 and 1965 that were fitted with an automatic gearbox controlled by electro-hydraulic systems. The trials found that such gearboxes were prone to frequent breakdowns in tanks. At the same time the Ob'yekt 155ML, a T-55 fitted with a launcher for three 9M14 "Malyutka" (NATO code: AT-3 Sagger) ATGMs mounted on the rear of the turret, was tested. Along with standard tanks a flamethrower-armed version was designed (designated TO-55 (Ob'yekt 482)), which was produced until 1962. It was fitted with 460 litre tanks filled with flammable liquid instead of the frontal hull fuel tanks. The flamethrower replaced the coaxial machine gun. This was a much better way to mount a flamethrower than in the experimental Ob'yekt 483, based on the T-54 tank, where the flamethrower replaced the main gun. TO-55 flamethrower tanks were withdrawn from service in 1993.
"By the standards of the 1950s, the T-54 was an excellent tank combining lethal firepower, excellent armor protection and good reliability"  while remaining a significantly smaller and lighter tank than its NATO contemporaries—the U.S. M48 Patton and the British Centurion. The 100-mm D-10T tank gun was more powerful than its Western counterparts.
In January 1945, some captured German tanks and vehicles were shipped to the Ordnance Research and Development Center, Aberdeen, Maryland, for tests and examination. The criteria for penetration in the tests was for at least fifty percent of the mass of the projectile to penetrate the armour. The M3 90 mm gun, firing the most widely equipped T33 armour-piercing round penetrated roughly 150 mm (6 in) of steel armour at 100 metres (330 ft), while the T30E16 HVAP round penetrated 270 mm (11 in) at the same range. These tests were carried out before the T-54/55 tank entered production, so it was not known how the popular 90 mm gun on the M46, M47, M48 and other western tanks would perform against the armour of the post-World War II Soviet tanks.
The data shows that the T33 AP round would fail to penetrate the frontal armour of the T-54/55 at any range, while the T30E16 HVAP round would only be able to penetrate the armour within 700 metres (2,300 ft). The T33 round could penetrate the side armour of the turret at about 800 metres, while the T30E16 HVAP round could do this at any practical range. The 90mm M431 HEAT round could penetrate the T-55 at any range, but had serious fusing problems when striking armor at a steep angle. This problem was later corrected. The most popular anti-armour round the Soviets used for the D-10 tank gun was the 100 mm BR-412 APHE, first used on the SU-100 tank destroyer during World War II with an 80% probability of penetrating 135 millimetres (5.3 in) of steel armour at 1,000 metres (3,300 ft) fired from the D-10S tank gun. The BR-412D and BR-412B rounds developed in 1946–1950 had slightly superior performance over the 90 mm T33 and the M82 armour-piercing rounds.
This disadvantage lasted until the Soviet tanks began to be surpassed by newer Western developments like the M60 main battle tank and upgraded Centurions and M48 Pattons using the 105 mm rifled Royal Ordnance L7gun. Due to the lack of a sub-caliber round for the 100 mm gun, and the tank's simple fire-control system, the T-54/55 was forced to rely on HEAT shaped-charge ammunition to engage tanks at long range well into the 1960s, despite the relative inaccuracy of this ammunition at long ranges. The Soviets considered this acceptable for a potential European conflict, until the development of composite armour began reducing the effectiveness of HEAT warheads and sabot rounds were developed for the D-10T gun.