Development on the 155 mm Gun Motor Carriage, M12 was started in June 1941. Production did not start until March 1942, however, as the US Army did not consider a self-propelled gun necessary at the time. It was equipped with a World War 1 field gun, which was removed from its carriage and mounted on a Medium Tank, M3 chassis.
The production run of 100 155 mm GMC, M12s was initially used for training purposes. Out of these 100, 74 later took part in the invasion in Normandy, alongside the more modern 155 mm Gun Motor Carriage, M40. An ammunition carrier variant, the Cargo Carrier, M30, was also made by removing the gun and recoil blade.
| 155 mm Gun Motor Carriage, M12 | |
|---|---|
| Crew | |
| Crew | 6 |
| Physical Characteristics | |
| Weight | 26.3 t |
| Length | 6.73 m |
| Width | 2.67 m |
| Height | 2.69 m |
| Performance | |
| Speed (max) | 38.6 km/h |
| Engine | |
| Engine | Continental R-975 |
| Net h.p. | 353 |
| Armament | |
| Primary weapon | 155 mm M1918M1 (1) |
| Secondary weapon | .50 cal. Browning Machine Gun (1) |