M13 Multiple Gun Motor Carriage

The M13 Multiple Gun Motor Carriage (MGMC), otherwise known as the M13 half-track, was a self-propelled anti-aircraft gun used by the U.S. Army during World War II that was armed with two .50 caliber M2HB heavy-barrel Browning machine guns. Developed in response to a requirement for a mobile anti-aircraft (AA) vehicle, the vehicle was produced by the White Motor Company between July 1942 and May 1943. The only time it was ever used in combat was when the Americans landed at Anzio in January 1944. It was replaced by the more heavily armed M16 Multiple Gun Motor Carriage in April 1944. The M13 evolved from a series of several unsuccessful prototypes that were trialed from 1940 to 1942. Of these, the T1E4 was selected and given the official name of the M13 MGMC, before being placed into production. Half of the M13s produced were converted into M16s on the production lines. The M13 half-track was long, wide, and high with a wheelbase of . It had bogie suspension for the wheels and vertical volute springs for the tracks. It had a fuel capacity and a range of . The vehicle was powered by a six-cylinder White 160AX, , gasoline engine, with a compression ratio of 6.3:1. It had a power-to-weight ratio of and weighed . The armor across most of the vehicle was thick with a thick windscreen visor. The vehicle was armed with two 0.5 inch M2 Browning heavy machine guns placed on an M33 Maxson mount. The two machine guns were fired remotely and powered by a small electrical motor near the back of the turret. The guns were aimed with a Mark 9 reflector sight. Each vehicle had a crew of five (commander, driver, gunner, and two ammunition loaders). In October 1940, development began to produce a vehicle in response to a long-standing requirement for an anti-aircraft vehicle to protect the U.S. Army's mechanized troop convoys from aerial attack. The first vehicle produced in the development of a half track with an anti-aircraft armament was the T1, which had two M2 machine guns on a Bendix machine gun mountas used on jeepson a 4×4 truck.