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United States' M40 Gun Motor Carriage
M43 Howitzer Motor Carriage
T83 Prototype Imperial War Museum |
T83 Prototype Pressed Steel Car Co.5 |
M40 Aberdeen Tank Museum |
M40 |
M43 |
Design
A replacement was needed for the M12 GMC (Gun Motor Carriage) as the supply of M1918 guns was exhausted and it's chassis was unsuitable for the more powerful M1 and M2 155 mm guns.1,6
Used M4A3 chassis that was widened and used the high volute suspension springing (HVSS).1,6 The engine was moved to the front and a spade was placed in the rear to help absorb some of the recoil.1,5,6
Front Crew Compartment
The M40 had a compartment in the front that the driver sat in.6 Beside him was the co-driver.6 The M40 had an escape hatch located just behind the co-driver.6
The driving compartment had 2 hatches in the roof for access.
Engine
Behind the crew compartment was the engine.6
Armament
The M40's main armament was located in the rear of the vehicle.6
Gun had range of 25,175 yards with a 95 lb round.4
Rear Fighting Compartment
The gun crew would stand on a hinged platform when firing the gun.1
Intended to be used well behind the front lines so no protection for the fighting compartment was provided.6
Prototype
The T83 was developed from M4 Medium tank components. It had a wider hull and used the new horizontal volute spring suspension.
On March 18, 1944, 5 pilot models of the T83 were authorized to be built. These were built by the Pressed Steel Car Company.6
The 8" howitzer was developed after successful trials of the T83 and designated the T89.1
Production
Was standardized in November 1945. 576 ordered (48 finished), but was cancelled when war ended.1,6 304 T83s and 304 T30s (cargo carriers) were ordered and production started in January 1945.1
- M40 Gun Motor Carriage: 3111, 4186
- Manufactured by: Pressed Steel Car Co.4,5,6
- Production: February 1945 - late 19456
- M43 Gun Motor Carriage:
1945: 481,6
- Manufactured by: Pressed Steel
- Production: January 1945, August 19456
Variants
- T30 Cargo Carrier: Designed to carry crew and ammunition.5
- T83 Gun Motor Carriage: Prototype for M40 Gun Motor Carriage. Had 155 mm M2 "Long Tom" gun on a widened M4A3E8 chassis.5
- T89 Gun Motor Carriage: Prototype for M43 Gun Motor Carriage.
- M40 Gun Motor Carriage: Mounted 155 mm Gun M1 or M2 in a Mount M3. Standardized in May 1945.1
- M43 Howitzer Motor Carriage: Mounted 8" howitzer M1 or M2 in a Mount M17.
Usage
A few took part in attack on Cologne (first use).5,6
Post World War II
The M40 was used in the Korean War by the United States Army.6
Britain
Britain bought some of the M40s and M43 and these were in service until the early 1960s.6
| M40 Gun Motor Carriage | M43 Howitzer Motor Carriage | ||
|---|---|---|---|
| Crew | Commander, driver, gun crew (6)2,5 81,2,3,4,5,6 |
Commander, driver, gun crew (6)2 82 |
|
| Physical Characteristics | |||
| Weight | 80,020 lb | 80,020 lb2,5, 82,000 lb3 36.6 tons1, 40 tons6, 40.5 tons4 37,195 kg1,3, 40,640 kg6 |
80,020 lb2 |
| Length w/gun | 29.7'4, 29' 8"3, 29' 9"2,5,6 9.04 m3,6 |
29' 9"2 | |
| Length w/o gun | 20.6'4, 20' 7"2,5, 21' 10"1,3 6.65 m1,3 |
||
| Height | 8' 9.5" | 8' 9.5"2,5, 8' 10"6, 9' 4"1,3, 10.8'4 2.69 m6, 2.84 m1,3 |
8' 9.5"2 |
| Width | 10' 4" | 10.3'4, 10' 4"1,2,3,5,6 3.14 m1, 3.15 m3,6 |
10' 4"2 |
| Width over tracks | |||
| Ground clearance | 17" | 19.25"4 | |
| Ground contact length | 13' 8" | 164"4 | |
| Ground pressure | 10.7 psi4 | 10.6 psi | |
| Turret ring diameter | |||
| Armament | |||
| Main | 155 mm3 155 mm M1A11,6 |
8" howitzer6 8" howitzer M1 in mount M17 203 mm howitzer6 203 mm (8") M1 Howitzer1 |
|
| OR | 155 mm M22,5 155 mm M2, L/454 |
8" howitzer M2 in mount M17 | |
| Secondary | |||
| MG | |||
| Side arms | 8: M1 carbines Hand grenades Anti-Tank grenades |
||
| Quantity | |||
| Main | 202,4,5 | 16 | |
| Secondary | |||
| MG | |||
| Side arms | 960 12 10 |
||
| Armor Thickness (mm) | 0.47"6 122,5,6 Front: 0.5"4 Side: 0.5"4 |
122 | |
| Hull Front, Upper | 0.5"@58° | ||
| Hull Front, Lower | 2-4.25"@0-46° | ||
| Hull Sides, Upper | 0.5@0° | ||
| Hull Sides, Lower | 1"@0° | ||
| Hull Rear | 0.5"@0° | ||
| Hull Top | 0.5@85° | ||
| Hull Bottom | 0.5-1"@90° | ||
| Turret Front | Gun shield: 0.5"@45° | ||
| Turret Sides | |||
| Turret Rear | |||
| Turret Top | |||
| Engine (Make / Model) | Continental R-975 C41 Continental R-9752,5 Continental3,4,6 |
Continental R-9752 | |
| Bore / stroke | |||
| Cooling | Air4 | ||
| Cylinders | Radial6, R-93,4 | ||
| Capacity | |||
| Net HP | 3953,6, 400@2,400 rpm4 | ||
| Power to weight ratio | |||
| Compression ratio | 5.7:14 | ||
| Transmission (Type) | Automatic4 5 forward, 1 reverse4 |
||
| Steering | Controlled differential | ||
| Steering ratio | |||
| Starter | Electric4 | ||
| Electrical system | 24-volt4 | ||
| Ignition | Magneto4 | ||
| Fuel (Type) | Gasoline4, Petrol6 | ||
| Octane | |||
| Quantity | 215 gallons | 215 gallons4 | |
| Road consumption | 0.5 mpg4 | ||
| Cross country consumption | |||
| Performance | |||
| Traverse | 18° left and right | 18° left and 18° right2,4,5 | |
| Max speed | 24 mph | 24 mph1,2,3,4,5,6 38 kph1, 38.6 kph3,6 |
24 mph2 |
| Cross country speed | 5 - 20 mph | 5-20 mph2,4, 20 mph5 | 5-20 mph2 |
| Road radius | 107 miles | 100 miles1,3,6, 107 miles2,4,5 160 km1, 161 km3,6 |
107 miles2 |
| Cross country radius | |||
| Turning radius | 83' | ||
| Elevation limits | +45° to -5° | -5° to +45°2,4,5 | |
| Fording depth | 3' 6" | 3'2,4,5, 3' 6"3 1.067 m3 |
3'2 |
| Trench crossing | 7' 8.5" | 7.7'4, 7' 8.5"2,5 | 7' 8.5"2 |
| Vertical obstacle | 2' 10" | 2' 10"2,4,5 | 2' 10"2 |
| Climbing ability | 31° (60%) slope4 | ||
| Suspension (Type) | High volute suspension springing | Horizontal volute spring4 Horizontal volute spring suspension (HVSS)5 |
|
| Wheels each side | 6 | 3 bogies of 2 wheels each4 | |
| Return rollers each side | 2 | 24 | |
| Tracks (Type) | Rubber block, double pin shoe4 | ||
| Length | |||
| Width | 23" | 23"2,4,5 | 23"2 |
| Diameter | |||
| Number of links | 794 | ||
| Pitch | 6"4 | ||
| Tire tread | |||
| Track centers/tread | 8' 4.75" | 8.4'4, 8' 4.75"2,5 | 8' 4.75"2 |
Sources:
- The Encyclopedia of Tanks and Armored Fighting Vehicles - The Comprehensive Guide to Over 900 Armored Fighting Vehicles From 1915 to the Present Day, General Editor: Christopher F. Foss, 2002
- British and American Tanks of World War Two, The Complete Illustrated History of British, American, and Commonwealth Tanks 1933-1945, Peter Chamberlain and Chris Ellis, 1969
- The Encyclopedia of Weapons of World War II, Chris Bishop, 1998
- Tank Data, Aberdeen Proving Grounds Series, 1968?
- Profile: AFV Weapons 26: Hellcat, Long Tom and Priest and Complete Check List of all U.S. World War II Self-Propelled Weapons, Colonel Robert J. Icks, 1971
- World Encyclopedia of Armored Fighting Vehicles, Jack Livesey, 2006
