M114
Type	Howitzer
Place of origin	United States
Service history
In service	1942–present
Used by	See operators
Wars	List of Conflicts World War II Korean War Vietnam War Cambodian Civil War Laotian Civil War Lebanese Civil War Salvadoran Civil War Iran–Iraq War Kurdish–Turkish conflict (1978–present) Yugoslav Wars Syrian Civil War
Production history
Designed	1939–1941
Manufacturer	Rock Island Arsenal (U.S.)
Produced	1941–1953 (U.S.)[1]
No. built	10,300 (U.S.)[1]
Variants	none
Specifications
Mass	Travel: 5,800 kg (12,800 lb) Combat: 5,600 kg (12,300 lb)
Length	Travel: 7.315 m (20 ft)
Barrel length	Bore: 3.564 m (11 ft 8 in) L/23 Overall: 3.79 m (12 ft 5 in) L/24.5
Width	Travel: 2.438 m (8 ft)
Height	Travel: 1.8 m (5 ft 11 in)
Crew	11
Shell	Separate-loading bagged charge
Caliber	155 mm (6.1 in)
Breech	Slow-cone interrupted screw
Recoil	Hydro-pneumatic
Carriage	Split trail
Elevation	−2°/+63°
Traverse	25° left or right
Rate of fire	burst: 4 rpm sustained: 40 rph
Muzzle velocity	563 m/s (1,847 ft/s)
Maximum firing range	14,600 m (16,000 yd)

The M114 is a towed howitzer developed and used by the United States Army. It was first produced in 1942 as a medium artillery piece under the designation of 155 mm Howitzer M1. It saw service with the US Army during World War II, the Korean War, and the Vietnam War, before being replaced by the M198 howitzer.

The gun was also used by the armed forces of many nations. The M114A1 remains in service in some countries.

Development

After the end of the First World War a board later labeled the Westervelt Board was convened to assess the artillery experience of the combatant powers and map out future directions for the US Army artillery. The conclusion of the board vis-a-vis corps (heavy field) artillery was that an ideal heavy howitzer should have range of at least 16,000 yards (15 km) and allow the elevation of 65°^[2] (as opposed to the existing World War I-era M-1918 155 mm howitzer's, a license-built French Canon de 155 C modèle 1917 Schneider, 11.5 km and +42° 20' respectively). Board also recommended that the new 155-mm howitzer and the new 4.7-inch (120 mm) gun share all the carriage, even if it compromises both designs.

The M1920 carriage resulting from this requirements was of the split-trail type with pneumatic equilibrators, permitting a total traverse of 60°.^[2] Unfortunately, it "gave considerable trouble due to the persistent failure of the top carriage" on the firing tests.^[3] In 1923–1925 the design was modified with the top carriage reinforced, with the result standardized as M1925.^[3] However, it was never built in steel, because after the evaluation of a wooden model the project was abandoned.^[3] Instead, two new carriages were developed and built in the following years, which were designated T1 and T1E1.^[3] All of them had the same ballistics (perhaps even the same gun body), with maximal range of 16,390 yards (14.99 km), and were undergoing tests in early 1930s.^[3] By 1934, the US Army was concerned about the arising high-speed towing requirements not satisfied by the plain bearings and solid rubber ties.^[4]

In 1939 the development began anew,^[5] by spring 1941 the first specimen was ready to be test-fired and immediately after passing them^[6] it was standardized on 15 May 1941 as Howitzer M1 on the Carriage M1. The howitzer itself differed from the older model by a lengthened barrel of 20 calibers and a new breech mechanism. Uniquely it was the sole 'slow-cone' interrupted screw mechanism to enter US service after 1920.^[5]

Carriage variants

The carriage was also used by the 4.5 inch Gun M-1. It went through a number of minor changes over time. The original Warner electric brakes were replaced by Westinghouse air brakes on the M1A1. Both the M1 and M1A1 carriages used a mid-axle firing pedestal that was extended by a ratchet mechanism. The M1A2 replaced the ratchet with a screw-jack system and also modified the traveling lock. The M1A1E1 carriage was intended for use in jungle and muddy terrain and replaced the wheels of the M1A1 with a free-wheeling tracked suspension, but the project was terminated after V-J day without having reached production. The T-9 and T-10 carriages were projects using low-grade steel alloys that were canceled when no longer needed. The T-16 was a light-weight carriage using high-grade steel that was estimated to save some 1,200 lb (540 kg); work began in July 1945 and continued after the war, although nothing seems to have come from it.^[5]

A mid-1960s variant was the 155mm XM123 & M123A1 auxiliary-propelled howitzers. The XM123 was produced by American Machine and Foundry and outfitted with two 20 horsepower air-cooled engines produced by Consolidated Diesel Corporation, driver's seat, steering wheel, and guide wheel on the left trail, allowing it to be more rapidly emplaced when detached from the prime mover, while the XM123A1 provided a single 20 horsepower motor with electric steering. The extra weight on the left trail displaced the howitzer after each round was fired, requiring it to be realigned, and the project was abandoned. The concept was copied from the Soviet 85mm SD-44 auxiliary-propelled antitank gun developed in 1954 and used by airborne forces.^{[citation needed]}

Self-propelled mounts

The howitzer was experimentally mounted on a lengthened chassis of the M5 light tank. The resulting vehicle received the designation 155 mm Howitzer Motor Carriage T64. A single prototype was built before the T64 project was abandoned in favor of T64E1, based on the M24 Chaffee light tank chassis. This was eventually adopted as the M41 Howitzer Motor Carriage and saw action in the Korean War.^[7] Towards the end of the Korean War the US Army replaced the M41 self-propelled howitzer with the M44 self-propelled howitzer.^{[citation needed]}

Ammunition

The gun fires separate-loading, bagged charge ammunition, with up to seven different propelling charges, from 1 (the smallest) to 7 (the largest). Muzzle velocity, range and penetration in the tables below are for maximum charge in form of complete M4A1 propelling charge.

Operators

Country	Number	Variant	Notes
Current operators
Turkey	~553	M114A1 / M114A2	[10]
Greece	~230	M114	[10]
Portugal	~24	M114A1	[10]
South Korea	~1800	KH-179	[10]
Laos	~12	M114	[10]
Pakistan	~144	M114	[10]
Philippines	~10	M114	[10]
Taiwan	~250	T-65	[10]
Vietnam	n/a	M114	[10]
Iran	~70	M114	[10]
Jordan	~18	M114	[10]
Lebanon	~18	M114A1	[10]
Morocco	~29	M114	[10]
Saudi Arabia	~50	M114	[10]
Tunisia	~12	M114A1	[10]
Argentina	~6	M114	[10]
Brazil	~103	M114	[10]
Ecuador	~12	M114	[10]
Peru	~36	M114	[10]
Uruguay	~8	M114A1	[10]
Venezuela	~12	M114A1	[10]
Sudan	~12	M114A1	[10]
Ukraine	~70	M114	[11][12]
Former operators
Thailand	~48	M114	[10]

Former operators

•  Denmark^[13]
•  Italy^[13]
•  Japan 220 total, a small number were produced domestically as Type 58. All retired.^[14]
•  Norway^[13]
•  Netherlands^[13]
•  Spain^[13]
•  United States^[13]