The 155-mm Gun Motor Carriage M12 was a U.S. self-propelled gun developed during the Second World War. Only 100 were built; sixty in 1942 and another forty in 1943. The M12 was built on the chassis of the M3 Lee tank. It had an armored driver's compartment, but the gun crew were located in an open topped area at the back of the vehicle. An earth spade at the rear was employed to absorb recoil. During 1943 the vehicles were used for training or put...