In the late 1940s, work began on a new heavy tank, the IS-8, with an improved 122mm D- 25TA gun, longer hull, and more powerful engine. It was accepted for service in 1952, but the tank was renamed the T-10 after Stalin’s death in 1953.
The hull is made of rolled armour, divided into three compartments. The driver is in the front, the fighting compartment in the centre, and the engine in the rear. The turret is cast steel. The gunner and commander are positioned to the left of the gun, the loader to the right. Armament consists of a 122mm D-25TA gun with a double-baffle muzzle brake, a 12.7mm DShKM co-axial machine gun, and another 12.7mm DShKM anti-aircraft machine gun at the loader’s hatch.
Just as the M103 was to provide fire support for the M48, and the Conqueror was to supply the same for the Centurion, so the T-10 was to back up the T-54/55s. The T- 10’s modified 122mm D-74 gun fired a massive 25kg (551b) armour-piercing round at a muzzle velocity of 885 metres per second (2900 feet per second) and could penetrate 185mm (7.28in) of vertical armour at 1000m (3280ft). In other words, it could blow holes in anything it might meet. Like all guns employing separate projectile and charge, the D- 74 was relatively slow to load, and two to three rounds per minute was the practical limit to the T-10’s rate of fire. As in the case of the T-54/55, the small angle of depression of the gun – just three degrees in the T-10 – posed problems in firing from hull-down positions. The angle of depression was limited by the low profile of the turret: there simply was not room to get the breech any higher. The danger to the tank was minimised, however, by its 120mm (4.75in) of sharply angled frontal armour, and by the good all-round ballistic shape of the hull and turret. And despite the T-10’s considerable weight, its 700hp V-2-IS V-12 diesel engine, a development of that originally produced for the A-20 tank in the mid-1930s, produced a top speed of 42km/h (26mph). Nine hundred litres (238 US gallons) of fuel gave the tank a range of only 250km (155 miles), which was low by Soviet standards but was perfectly adequate for a support tank such as this. The T-10 had 710mm-wide (28in) tracks in order to keep the ground pressure within reasonable bounds.
In 1956, the T-10A added stabilisation for the main gun in one plane. In 1957 the T-10B added stabilisation in two planes and infra-red searchlights to the right of the main armament and forward of the commander’s hatch. The T-10M was introduced later in 1957. This version had NBC protection and a new M-62-T2 gun with multi-baffle muzzle brake. The 12.7mm DShKM machine guns were replaced with 14.5mm machine guns (KPVT in the co-axial mount, KPV at the loader’s hatch). The T-10M was produced at two different plants, with incompatible parts, until 1962, when a single design was finally settled on. From 1963, T-10Ms were fitted with deep-wading snorkels, and from 1967 they were supplied with APDS and HEAT ammunition.
Expensive to build, heavy, and difficult to maintain logistically, the T-10 was phased out in the mid-1960s in favor of the T-62. It equipped a number of Warsaw Pact armies and was exported to both Egypt and Syria.
T-10A (1956): T-10 with an added single-plane gun stabilizer.
T-10B (1957): T-10 with an added 2-plane gun stabilizer.
T-10M (1957): Modernized version with longer M-62-T2 L/46 gun with five-baffle muzzle brake, 2-plane gun stabilizer, machine guns replaced with 14.5 mm KPVT (a better ballistic match for the new main gun), infrared night vision equipment, NBC protection. Overall length is 10.29 m.
1963 – T-10M is equipped with OPVT deep-wading snorkel.
1967 – T-10M is supplied with APDS and HEAT ammunition.
Combat weight: 52 tonnes
Length: 7.41m (9.87m including gun)
Width: 3.56m Height: 2.43m
Ground clearance: 0.43m
Maximum road speed: 42km/h
Maximum road range: 250km
Vertical obstacle: 0.9m
Armament: 1x 122mm D-25TA gun (T-10M: 122mm M-62-T2) 2x 12.7mm DShKM MG (T-10M: 1x 14.5mm KPV, 1x 14.5mm KPVT)
Armour: Hull front upper: 120mm @ 60° Hull front lower: 100mm @ 55° Hull side: 90mm @ 60° Hull rear upper: 60mm @ 30° Hull rear lower: 30mm @ 50° Hull top: 35mm Belly: 20mm Turret front: 250mm Turret mantlet: 250mm Turret sides: 75-115mm Turret rear: 60mm Turret top: 30mm