As a replacement for the WWII era T-34 the T-55 was produced in the USSR from 1963 – 1981 and under license in Poland from 1964 – 1979 as well as in Czechoslovakia and in China as the Type 59. During the “Cold War” period it was felt that there was a need for a new anti-radiation system for the T-55. A new lining and full chemical filtration system were added to the tanks and these became known as the T-55A. A T-55A is distinguishable because these modifications made it necessary to enlarge the Driver’s hatch and enlarge the combing over the Commander’s and Loader’s hatch. The new improvements brought about the removal of the bow machine gun. The coaxial machine gun was updated and room for 6 more main gun rounds (100mm) was made possible with the removal of the hull machine gun. Starting in 1970 a new turret fitting was adding to the T-55A to accommodate the new 12.7mm anti-aircraft heavy machine gun.