Image: M12 GMC (U.S. Army Photo)
YearSeptember 1942
Vehicle Type[@type]
Origin & Designer[@designer]
Numbers Produced100
Crew6 (Commander, Gunner, Two Loaders, Radio Operator & Driver)
Main Armament1 x 155mm L/36 M1917A1, M1918M1 or M1919 Gun
Main Armament[@sponson_traverse]
Elevation-5° to +30°
Turret Traverse14° Left & Right (Manual)
Gun Traverse[@gun_traverse]
Gun Mount[@gun_mounts]
Maximum Range[@maximum_range]
Armour Penetration[@armour_penetration]
Gun Sight6.73m
Secondary Armament1 x .50 cal M2HB Heavy Machine Gun (AA Mount)
Smoke Discharger[@smoke_discharger]
Ammunition Carried10 x 155mm & 1000 x .50 cal
Combat Weight27.000 kg
Ground Clearance0.43m
Fording Depth1.0m
Trench Crossing2.30m
Obstacle Clearance0.61m
Climbing Ability30°
RadioSCR 610
ArmourUpper Hull Front: 25mm.
Lower Hull Front: 51mm.
Upper Hull Sides: 10mm.
Lower Hull Sides: 19mm.
Hull Rear: 19mm.
Hull Top: 25mm.
Hull Bottom: 13mm.
Open Gun Compartment.
EngineContinental R975 C1 (Petrol)
Transmission5 Forward & 1 Reverse
Maximum Road Range139 miles (225 km)
Maximum Cross Country Range87 miles (140 km)
Maximum Water Range[@maximum_water_range]
Maximum Road Speed21 mph (34 kph)
Maximum Cross Country Speed12 mph (19 kph)
Maximum Water Speed[@maximum_water_speed]
NotesThe M12 was built on the M3 tank chassis and mounted either the M1917, M1917A1 or M1918M1 gun in an open compartment. It was initially developed as a training vehicle and hundred were built in 1942 with some used for training and others placed in storage. Just before the allies landed in France, 74 M12s were dusted off and taken to Europe, these saw action during operation Cobra and later used in the direct fire mode against enemy strong points. Due to the lack of space the M12 could only carry 10 rounds, so the M30 Ammunition carrier was developed, this was basically a M12 without the gun and could carry a full gun crew plus 40 rounds of ammo. After World War Two the M12 was withdrawn from service and replaced by the M40 GMC.