The TO-55 was a modification of the T-55 fitted with a flamethrower, intended to assist infantry in pushing against enemy defensive positions during battle, while allowing for increased survivability of such a weapon system when compared to flamethrowers carried by infantry. The original tank turret was modified by incorporating an ATO-200 flamethrower coaxial with the main armament. The standard ammunition stowage in the bow next to the driver was modified to accommodate a flammable liquid tank with a capacity of 460 litres. The flamethrower was aimed by rotating the entire turret, and ignited by pyrotechnic charges. Instead of being manually controlled, the rate of fuel consumption was standard, averaging 36 litres per burst of flame. The flamethrower had a maximum effective range of about 200 metres and an initial muzzle velocity of about 100 meters per second.