The T-55 medium tank is a further development of the T-54B. It has some improvements over its predecessor that are hard to notice externally, but these improvements made the tank more efficient and lethal. The T-55 was officially adopted by the Soviet Army in 1958. Its production commenced during the same year. It is esᴛι̇ɱated that around 70 000 T-54 and T-55 tanks were produced in the Soviet Union, Czechoslovakia and Poland.

Since its introduction the T-55 has seen combat in more than 20 ωɑɾs. Russian Army withdrawn last T-55 tanks from active service in 2016. Though despite its age this medium tank is still used by around 50 countries from all around the world. Both the T-54 and T-55 were heavily influenced by the Soviet experience gained during the WW2. The T-55 was the first Soviet tank, fitted with an efficient NBC protection system. At the ᴛι̇ɱe it was the only tank in the world, capable of fighting after a nearby nuclear explosion.

This tank has a welded steel armor hull and a cast turret. Front of the hull has a 60° inclination in order to increase protection. This tank is also fitted with automatic fire suppression system, that was a novelty at the ᴛι̇ɱe. The T-55 can launch its smoke screen by injecting diesel fuel into exhaust. The T-55 is fitted with a fully-stabilized 100 mm gun. It can fire accurately on the move. At a speed of 12 km/h the tank has a first round hit probability of about 60%. A total of 43 rounds are carried. The previous T-54 carries only 34 rounds.

On initial production tanks the roof-mounted 12.7 mm machine gun of the T-54 was removed, because it was ineffective against jet aircraft. In the late 1950s combat helicopters were still under development. The 12.7 mm machine gun was fitted back only in 1970. This tank is operated by a crew of four, including comɱaпder, gunner, loader and driver.

This tank is powered by a 39-liter V-55 diesel engine, developing 520 hp. It replaced the less powerful and unreliable V-45 diesel engine of the T-54. Maximum road speed is about 50 km/h. Cross-country speed is about 25 km/h. Maximum range on fuel, including external tanks, is up to 530 km. The T-55 can be fitted with a deep wading kit and ford water obstacles up to 5 m deep. Since its introduction the T-55 was constantly upgraded. Various countries offer a number of upgrade programmes for this ageing tank. However even updated T-55 tanks are no match for modern MBTs.