The M47 Patton is an American medium tank, the second tank to be named after General George S. Patton, commander of the U.S. Third Army during World War II and one of the earliest American supporters of tanks in battle. It was a further development of the M46 Patton tank. The M47 was the U.S. Army's and Marine Corps' primary tank, intended to replace the M46 Patton and M4 Sherman medium tanks. The M47 was the only Patton series tank that never saw combat while in United States service. Many different M47 Patton models remain in service internationally. The M47 Patton was developed by the Detroit Arsenal, and entered production in 1951. Its main gun was the M36 (T119E1) 90-mm gun with an M12 optical rangefinder fitted. The secondary armament consisted of two .30cal Browning machine guns, one in the bow of the hull and one coaxial machine gun in the turret, and a .50cal Browning M2 on a pintle mount on the turret roof. The M47 was the last American designed tank to include a bow machine gun. Created in 1955, this field manual reveals a great deal about the Tank, 90-mm Gun, M47's design and capabilities. Intended as a manual for those responsible for both learning and teaching its characteristics, it details many aspects of the M47's fire commands, firing duties, crew drill and service of the piece. Originally labeled restricted, this manual was declassified long ago and is here reprinted in book form. Care has been taken to preserve the integrity of the text."