Britain’s Main Battle Tank for 20 years, Chieftain was one of the first true Main Battle Tanks, designed to replace both medium and heavy tanks in front line service. Its design incorporated a lot of revolutionary features. For example, in order to reduce height, the driver lies in a reclining position and changes gear with his foot. The gun uses a self-combusting, bagged charge in place of a brass cartridge case, and the tank is powered by a multi-fuel engine. | The Tank Museum