Combat Mass: 40 mt
Armament: 115 mm U-5TS (2A20) SB (40 rds); 12.7 mm DShK 1938/46 AA MG ; Coaxial 7.62 mm PKT MG (2500 rds)
Engine: V-55 12 cyl wc diesel 581 hp (433 kW); Power/weight ratio 14.5 hp/t
Speed: Road 50 km/h - Cross Country 45 km/h
Operating Range: Road 650 km - Cross Country 450 km
By 1955, the T54 and T55 had been mass-produced and upgraded, but the western powers kept on innovating as well and unveiled excellent medium tanks. There was already a pressing demand to find an answer fit to western models like the M47 Patton and Centurion which frontal armour can deflect or defeat 100 mm rounds. As a result, engineers devised the 100 mm HEAT round, at first costly (and at that time the crew did not have the required training to deal with these ammo), although it had the theoretical advantage to fit into a similar (but smoothbore) barrel. No new tank model was envisioned, but this was infirmed in january 1961, when a disgruntled Iranian officer defected to USSR with his brand new M60A1. At that time engineers devised an APFSDS round which was easier to operate and could be produced in larger quantities. However the latter was 115 mm in caliber, and needed a higher muzzle velocity to be effective.
Therefore new guns were tried. In 1957-58 with the D54T. Later in 1961 with the new smoothbore 115 mm (4.53 in) integrated into the T-55, but trials eventually failed. There was no way to obtain the room needed for the recoil other than dramatically increasing the turret ring. And to support the new, heavier turret, to have a lengthened chassis. This modified T-55 became the T-62, eventually 25 pre-series were built in the summer of 1961, and by july, a full-scale production was ordered. When the production stopped in 1980 in North Korea (it stopped already in 1978 in Czechoslovakia, and 1975 in USSR) a total of 22 700 has been delivered, more than any other western model, but still far less than the combined T-54 and T-55 which were not completely replaced due to the introduction of new modern rounds compatible with the rifled gun. It found its mark on the soviet arsenal, was used by around thirteen operators, and well-proven in combat. Its numerous limitations and issues only appeared recently and explained its replacement early on by the far better T-72.