Heavy tank
The Char 2C was one of the largest tanks ever produced. At the start of World War II, France and the Soviet Union were the only countries to have inventories of heavy tanks, such as the Char B1, T-35, and KV-1. The Matilda II was designed under the British infantry tank concept which is similar to the heavy tank having thick armor and weighing more than their other tanks. It’s usually separate because they have less firepower with their cruiser tanks (comparable to mediums) at the time having the same main armament but more machine guns. Later war examples were the German Tiger I and II, as well as the Soviet IS series. Note that "heavy" versus "medium" is more a question of tactical roles than weight; the Panther, for example, was a "medium" tank that outweighed most Allied "heavy" tanks.
T-54/T-55 operators and variants
The T-54/T-55 tank series is the most widely used tank in the world and has seen service in over 50 countries. It has also served as the platform for a wide variety of specialty armored vehicles.Early on during the production T-55s were fitted with the TSh-2B-32P sight. Starting in 1970 T-55s were being armed at Uralwagonzavod 12.7 mm DShK 1938/46 or KPVT loader's anti-aircraft heavy machine guns. These tanks were known as Model 1970, or sometimes T-55AM. KTD-1 or KTD-2 laser rangefinders and R-123 or R-123M radio sets were fitted to older tanks starting in 1974 (Model 1974). At the same time efforts were made to modernize and prolong the life of the drive train.SU-122-54 (Ob'yekt 600) ("Samokhodnaya Ustanovka") – Self-propelled 122 mm gun, based on the T-54A and sometimes known as . Between 1955 and 1957, 77 vehicles were built with minor differences between production lots (different commander's cupola etc.). The SU-122-54 had a modified chassis, with small spaces between the first, second and fourth pair of wheels and a large gap between the third, similar to the T-62's and a superstructure, built into the hull, housing the 122 mm D-49 L/48.4 gun for which the vehicle carries 35 rounds. The secondary armament consisted of two KPVT heavy machine guns, one mounted as an anti-aircraft machine gun near the commander's hatch and the other mounted coaxially with the main gun. The vehicle carried 600 rounds for the machine guns. The main gun has a fume extractor positioned right behind the muzzle brake, some vehicles did not have the fume extractor. Other variations included a different commander's cupola.
Romanian TR-85 series tanks are sometimes mistakenly considered as locally produced T-55s; in fact they are related, but different designs.
A variant of this modification, intended for export, was armed with L7A1 105 mm gun.