M40 Gun Motor Carriage

155 mm gun motor carriage M40
155 mm gun motor carriage M40
	M40 in the US Army Ordnance Museum
Type	Self-propelled artillery
Place of origin	United States
Service history
In service	1945 – 1953
Used by	United States ; United Kingdom ; France
Wars	World War II ; Korean War
Production history
Designer	Ordnance Department
Designed	1944 – 1945
Manufacturer	Pressed Steel Car Company
Produced	1945
No. built	418 (24 converted to; 8" HMC M43)
Specifications
Mass	36.3 metric tons (80,000 lb)
Length	9.1 m (29 ft 10 in)
Width	3.15 m (10 ft 4 in)
Height	2.7 m (8 ft 10 in)
Crew	8 (Commander, driver, 6 gun crew)
Armor	12 mm
Main; armament	155 mm Gun M1A1 or M2 ; (20 rounds)
Engine	Wright (Continental) R975 EC2 ; 340 hp (253 kW)
Power/weight	9.36 hp/t
Suspension	HVSS (Horizontal Volute Spring Suspension)
Operational; range	170 km (106 mi)
Maximum speed	38 km/h (24 mph) on road; 23 km/h (14 mph) off-road

Last updated August 02, 2025

The 155 mm gun motor carriage M40 was an American self-propelled artillery vehicle built on a widened and lengthened medium tank M4/M4A1 chassis, with a Continental engine and with HVSS (Horizontal Volute Spring Suspension), which was introduced at the end of World War II.

Description

Equipped with a 155 mm M1A1 or M2 gun, it was designed to replace the earlier M12 gun motor carriage. Its prototype designation was the T83, but this was changed to the M40 in March 1945.

A single pilot vehicle was used in the European Theatre in 1945 by the 991st Field Artillery Battalion, along with a related 8-inch howitzer motor carriage T89, (later re-designated the M43 howitzer motor carriage) which was sometimes also equipped with a 155 mm barrel.^[1] A total of 311 out of a planned 600 were completed by the Pressed Steel Car Company before the end of the war, 24 of which were later converted into M43s. From there it was deployed during the Korean War.

After World War II, the M40 was used by the British Army, who designated it 155 mm SP, M40.

Gun section

A complete gun section consisted of one M40 GMC and one M4A1 high speed tractor towing a 4-wheel, 8-ton M23 ammunition trailer. Each battery had four gun sections. The M4A1/M23 combination replaced the earlier M30 cargo carrier.^[2]

Variants

8-inch HMC M43 in Korea Self-propelled-gun-Korea-19520813.jpg — 8-inch HMC M43 in Korea

The Army planned to use the same T83 chassis for a family of SP artillery:

Cargo carrier T30 – despite several being built, its production was cancelled in December 1944 to make more chassis available for GMCs
8-inch howitzer motor carriage M43 – 8 in (203 mm) HMC, standardized August 1945, 48 built
250 mm mortar motor carriage T94 – 10 in (250 mm) MMC, began design Feb. 1945, one prototype completed by 1946

Related vehicles

105 mm howitzer motor carriage M7B1 – self-propelled 105 mm howitzer motor carriage based on the M4A3 Sherman chassis
155 mm gun motor carriage M12 – self-propelled 155 mm gun motor carriage
- Cargo carrier M30 – an M12 with crew and ammunition space in lieu of the gun.

Surviving vehicles

one at The American Military Museum, El Monte (USA)^[3]
one at United States Army Ordnance Museum ^[3]
one at the Imperial War Museum, Duxford (UK)^[3]
one at Royal Artillery Museum, Woolwich (UK)^[3]
one at the Technik Museum, Sinsheim (Germany)^[3]
two M40 GMCs – Arkansas National Guard Mus, Camp Robinson, Little Rock, AR (USA)^[3]
one at City vehicle storage area, Charleston, AR (USA)^[3]
one at Fort Chaffee Maneuvering Training Center, AR (USA)^[3]
one at the United States Army Field Artillery Museum, Fort Sill, Ok (USA)^[3]
one in workshop at BAIV B.V., Nederweert, Limburg (Netherlands)^[4]

Notes

↑ Hunnicutt – Sherman: A History of the American Medium Tank, p 353-355, 570.
↑ "The M-40 and T-89 Motor Carriages – Real Military Videos". www.realmilitaryvideos.com. Archived from the original on 12 May 2014.
1 2 3 4 5 6 7 8 9 "U.S. Army Field Artillery Museum – Collections". army.mil. Retrieved 22 February 2016.
↑ "BAIV B.V. Website". 10 March 2025.

References

Hunnicutt, R. P. (1994). Sherman: A History of the American Medium Tank. Presidio Press. ISBN 0-89141-080-5.
Ness, Leland (2002). Janes World War II Tanks and Fighting Vehicles. HarperCollins. ISBN 0-00-711228-9.

External links

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.

[HUNNICUTT-SHERMAN-353-1] Hunnicutt – Sherman: A History of the American Medium Tank, p 353-355, 570.

[2] "The M-40 and T-89 Motor Carriages – Real Military Videos". www.realmilitaryvideos.com. Archived from the original on 12 May 2014.

[collections-3] 1 2 3 4 5 6 7 8 9 "U.S. Army Field Artillery Museum – Collections". army.mil. Retrieved 22 February 2016.

[4] "BAIV B.V. Website". 10 March 2025.

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