Early T-55s were fitted with a new TSh-2B-32P sight. In 1959, some tanks received mountings for the PT-55 mineclearing system or the BTU/BTU-55 plough. In 1967, the improved BM8 APFSDS round, which could penetrate 275 mm thick armour at a range of 2 km, was introduced. In 1970, new and old T-55 tanks had the loader's hatch modified to mount the 12.7 mm DShK machine gun, to deal with the threat of attack helicopters. Starting in 1974, T-55 tanks received the KTD-1 or KTD-2 laser rangefinder in an armoured box over the mantlet of the main gun, as well as the R-123 or R-123M radio set.[14] Simultaneously efforts were made to modernize and increase the lifespan of the drive train.
T-55T-55AM2
T-55T-55AM2
T-55T-55AM2
T-55T-55AM2
T-55T-55AM2
