Today in WW II: 24 May 1941 Battle of the Denmark Strait: German battleship Bismarck sinks British battlecruiser HMS Hood, flagship of the Home Fleet, killing all but 3 of the 1418 crew. More ↓

24 May 1943 Dr. Josef Mengele, German SS officer and physician, becomes the medical officer at Auschwitz-Birkenau concentration camp.
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M-12 155mm Gun Motor Carriage

The M-12 Gun Motor Carriage mounted the M1 155mm gun on a modified M3 Lee medium tank chassis. The M12 was the first 155mm self-propelled artillery produced for the U.S. military, with 100 units delivered in March 1943. They were initially ignored, but were refurbished in late 1943 and proved to be very effective in Europe in the battles following the D-Day landings in France, June 1944. The refurbishment included use of the heavier suspension of the M4 Sherman tank with the rear-mounted return roller, a small shield was installed on the gun mount and the co-driver's hatch was removed.

The M-12 consisted of the M-3 tank chassis with the engine moved forward to accomodate the M4 mount for the 155mm gun. The gun was the M1917, M1917A1, M1918 or M1, very similar guns derived from the French 155mm GPF (Grande Puissance, Filloux), also the same as was used for the towed 155mm "Long Tom".

The rear of the hull was fitted with a spade/blade that could be lowered to the ground to anchor the rearward movement from the shock of the gun firing. The M30 Cargo Carrier was provided as an ammo carrier vehicle for the M-12. It was the same as an M-12 but without the 155mm gun.

The manufacturer was Pressed Steel Car Company of Pittsburgh, PA with Baldwin Locomotive in Philadelphia, PA performing refurbishment.

Find additional photos and hi-res versions of the M-12 155mm GMC at the Olive-Drab Military Mashup:

M12 155mm self-propelled artillery, circa 1943. The gun tubes for the M12 were made from GPF guns.

M12 155mm self-propelled Gun Motor Carriage, firing at German positions, ETO, circa March 1945.

M-12 155mm Gun Motor Carriage named Corregidor fires on German positions near St. Lo, France, 1944.

During the assault toward the Roer River, this 155mm Gun Motor Carriage M12 is firing on German held positions, circa November 1944.

M-12 155mm Gun Motor Carriage, Luxembourg, February 1945.

Specifications of the M-40 155mm Gun Motor Carriage

Crew	6
Weight	59,000 lbs.
Height	9 ft, 6 in.
Width	8 ft, 9 in.
Length	22 ft, 2 in.
Engine	Continental R975-C1 9 cyl. radial, gasoline
Horsepower	400 bhp.
Road Speed	24 mph.
Range	140 mi.
Manual	TM 9-751

M-12 155mm Gun Motor Carriage Photo Gallery

M-12 155mm self-propelled gun firing across the Moselle River in France, 1944
M12 155mm self-propelled gun firing across the Moselle River in France, 1944.

M12 155mm self-propelled gun, from TM 9-3305, Principles of Artillery Weapons.