The M37 105mm Howitzer Motor Carriage was developed to provide a lighter, more mobile replacement for the M7 105mm Howitzer Motor Carriage. It appeared too late to see service in the Second World War but was used in combat during the Korean War.
The M7 'Priest' was originally based on the chassis of the M3 Medium Tank, although later versions used the M4 Sherman as their base. The M7 had a new superstructure with an open fighting compartment. The 105mm howitzer was mounted just off-centre in the front of this compartment, with an anti-aircraft gun in a pulpit mounting at the front right (thus the nickname 'Priest').
The M37 was based on the chassis of the M24 Chaffee light tank. The project was authorised on 8 July 1943 as the T76 105mm Howitzer Motor Carriage. The T76 was very similar in layout to the M7. The superstructure and turret of the M24 was removed and a new open fighting compartment was designed. The M4 105mm howitzer was mounted in the front of the fighting compartment, just to the right of centre. As on the M7 a machine gun was carried on a 'pulpit' mount in the front-right corner of the fighting compartment. The pulpit-like appearance came about because the machine gun needed to be raised above the level of the howitzer to give 360 degrees of coverage. The raised gun position was protected by a curved sheet of armour that surrounded three quarters of the position.
The T76 had the same power train as the M5A1 Light Tank and the M24 Chaffee. It had the same torsion bar suspension with five road wheels as the M24, with four return rollers, a raised rear idler and front drive wheel. It was powered by two Cadillac 44T4 V-8 engines, providing 296hp. The engine was mounted in the rear, just as in the standard M24.
The first pilot T76 was ready for trials at the Aberdeen Proving Ground in July 1944. It then went to the Armored Force at Fort Knox for further tests. A number of modifications were then made. The machine gun ring was reduced in size. Shell storage was increased from 68 to 126 rounds.
In January 1945 the modified design was accepted for production as the M37 105mm Howitzer Motor Carriage. A total of 448 M37s were ordered, with production split between Cadillac and American Car and Foundry. Production wound down after the end of the war, and a total of 316 had been completed when production ended in October 1945.
The M37 saw combat in the Korean War, where it was used for infantry support and as mobile artillery. It was withdrawn from the front line after that war, and was replaced by the M52 Howitzer Motor Carriage, a turreted vehicle based on the M41 light tank. The M37 remained in use with National Guard and Reserve units until the early 1960s.
A number of M37s were exported, and some of them remained in use until the 1970s. Thirty six went to Spain where they equipped Regimiento de Artilleria a Caballo numero 19 of the Jarama Cavalry Division, and Regimiento de Artilleria de Campana numero 13 of the Brunete Armored Division
Hull Length: 18ft 2in
Hull Width: 9ft 11in
Height: 7ft 4in
Engine: Twin Cadillac V8 petrol engines
Max Speed: 35mph road speed
Max Range: 100-150 mile road radius
Armament: One 105mm M4 howitzer, one .50in anti-aircraft machine gun