The M40 and M43 Artillery systems were developed on an enlarged M4 Sherman chassis (M4A3E8). It had an open roofed compartment where the gun was mounted and operated by the crew. Whilst firing, the rear wall of the structure folded down into a platform to increase the working space for the crew as was the large stabilization blade.
4 pilot models were completed ready for trials in August 1944. 2 were the T83 (service designation M40) and 2 were the T89 (service designation M43).
The M40 Self Propelled Gun
The M40 used a 155mm main gun and could fire a variety of shells including hire explosive, white phosphorous and armour-piercing.
The M43 Self Propelled Gun
The M43 was fitted with a 203mm main gun, which weighted in at 4.5 tonne. It fired a high explosive 2-part shell weighting 109kg.
The T30 Supply Vehicle
The T30 was the same vehicle design as the M40, but lacked the gun and carried both the spare ammunition and some of the M40/M43 crew.
Production for an order of 304 M40 and 304 T30 started in January 1945. 576 M43 were ordered around May 1945. By the end of World War 2 production had ceased. 311 M40 and 48 M43 had been built. Some M40 were later converted into M43’s. The M40/43 saw limited action in WW2, but were used in the Korean War. They were also supplied to allies like Great Britain and France as part of the Military Assistance Program.
The American M40/M43 Self Propelled Gun Spec’s
Main Gun: 155mm (M40) 203mm (M43)
Armour: 100mm steel
Dimensions: Length 6.65m (excludes main gun), Width 3.14m, Height 2.54m
Weight: 37,195kg (37.195 metric tonne)
Engine: 395hp Continental R 975-C4
The T95 Self Propelled Heavy Mortar
Prototype fitted with a 250mm mortar for taking concrete bunkers apart, but was never produced.