M114 - 155 mm Howitzer

Development

In 1934, the development of a new split trail carriage was authorised under the designation T3. Development of the T3 was subsequently cancelled in favour of a new 155 mm howitzer (the T3) and a new carriage (the T2), which were standardised as the 155 mm Howitzer M1 and Carriage M1 in April 1941. The carriage was the same as that used for the 4.5 in field gun. By the time production of the M1 had been completed, just over 6,000 had been built. After the Second World War the complete weapon was redesignated the Howitzer, Medium, Towed: 155 mm, M114, consisting of the Cannon (M1 or M1A1), Carriage (M1A1) and Recoil System (M6, M6A1, M6B1 or M6B2). The M114A1 is almost identical to the M114 except that it has an M1A2 carriage.

Description

The howitzer consists of the breech ring, breech block, breech mechanism and barrel. The carriage M1A1 or M1A2 consists of top and bottom carriages, wheels and brake mechanisms, trails, equilibrators and the firing jack. The carriage is of the unsprung two-wheel split trail type with the wheels fitted with combat tyres for high-speed towing. The carriage is equipped with airbrakes, which are operated from the prime mover, and there are handbrakes on each wheel for parking. The barrel is balanced by spring-type equilibrators. The recoil mechanism, elevating and traversing mechanism, left and right shields, telescope mount and panoramic telescope are attached to the top carriage. The bottom carriage supports the weight of the top carriage and the barrel, and transmits operating stresses to the firing jack and trails. The counter-recoil system consists of the recuperator cylinder, counter-recoil cylinder, and the counter-recoil and recuperator cylinder head stuffing box which links the two cylinders hydraulically. The recoil system consists of the recoil cylinder, replenisher and variable recoil cam assembly. The M1 barrel is similar to the M1A1 but the M1A1 uses steels with increased physical properties. The M1A1 carriage has a rack-and-pinion-type firing jack and the M1A2 has a screw-type firing jack. The travelling lock of the M1A2 is equipped with a firing jack hanger whereas that of the M1A1 is not.

The M114 fires the following separate-loading ammunition: HE (M107) with the projectile weighing 42.91 kg, maximum muzzle velocity of 563.9 m/s and a maximum range (charge 7) of 14,600 m HE (M449) (carries 60 anti-personnel grenades) with the projectile weighing 43.09 kg, maximum muzzle velocity of 563.9 m/s and a maximum range (charge 7) of 14,600 m Illuminating (M485) with the projectile weighing 41.73 kg, maximum muzzle velocity of 576 m/s and a maximum range (charge 7) of 13,600 m Smoke (M116 series) with the projectile weighing 42.22 kg, maximum muzzle velocity of 563.9 m/s and a maximum range of 14,600 m Smoke WP (M110 series) with the projectile weighing 44.4 kg, maximum muzzle velocity of 563.9 m/s to a maximum range (charge 7) of 14,600 m M712 Copperhead Cannon Launched Guided Projectile M804 practice with a maximum range of 14,600 m. Note: Not all these types of 155 mm ammunition are in current use.

Variants

M114A2

It was originally understood that the M114A2 had the complete ordnance of the 155 mm M198 covered in detail in the previous entry. It has now been confirmed that the barrel of the 155 mm M114A2 is only slightly longer than that of the M114A1 with the key identification feature being a groove that is cut around the outside of the barrel about 50 to 70 mm from the end. The main tube difference is internal with the M114A2 tube posessing a 1 in 20 twist as opposed to the 1 in 12 twist used in earlier models. The greater twist extends the range of existing projectiles and other than the tube there are no additional changes in the M114A2 design. In mid-1997, the US government announced that it was to supply the Bosnian Federation with 116 ex-US Army 155 mm M114A2 towed howitzers held in reserve and all of these are to be delivered by the end of 1997. An additional 145 systems were earmarked for spare parts.

TITLE : Modified M114 (Netherlands) TEXT : Details of the M114/39 Modified Howitzer originally developed by SRC International and now produced by RDM Technology are given in this section under the Netherlands. Denmark, the Netherlands and Norway have now completed conversion of 230 M114s to the M114/39 configuration.

Modified M114 (Israel)

Full details of this conversion, developed as a private venture by Soltam of Israel, are given under Israel.

Modified M114 (Italy)

Details of the OTOBreda conversion are given in this section under Italy. This upgrade package remains at the prototype stage.

M114F (France)

Giat Industries of France has developed a conversion package for the M114, details are given under France. This upgrade package remains at the prototype stage.

KH179

Details of the South Korean KH179, a conversion of the M114, are given under Korea, South.

SPECIFICATIONS :

Calibre: 155 mm
Barrel length:
(muzzle to rear end of breech mechanism) 3.778 m
(excluding breech) 3.626 m
Muzzle brake: no
Recoil system: hydropneumatic
Breech mechanism: stepped thread, interrupted screw
Carriage: split trail
Shield: optional
Weight:
(travelling order) 5,800 kg
(firing position) 5,760 kg
Length:
(travelling) 7.315 m
Width:
(travelling) 2.438 m
Height:
(travelling) 1.803 m
Axis of bore:
(at 0) 1.676 m
Ground clearance: 0.229 m
Track: 2.07 m
Tyres: 14.00 x 20
Elevation/depression: +63/-2
Traverse:
(right) 25
(left) 24
Rate of fire:
(first 30 s) 2 rounds
(first 4 min) 8 rounds
(first 10 min) 16 rounds
(per hour, sustained) 40 rounds
Max range: 14,600 m
Crew : 11
Towing vehicle: 5 ton (6 x 6) truck

Status : Production complete. In service with Argentina, Austria, Bosnian Federation (116 delivered in 1997), Brazil (99), Cambodia, Canada, Chile (including Marines), Denmark, El Salvador, Ethiopia, Greece, Iran, Iraq, Israel, Italy, Jordan, South Korea, Laos, Lebanon, Libya, Morocco, the Netherlands, Norway, Pakistan, Peru, the Philippines, Portugal, Saudi Arabia, Senegal, Somalia (6), Spain, the Sudan (12), Taiwan (including self-propelled model on M108/M109 chassis, details of which are given in the Self-propelled guns and howitzers (tracked) section), Thailand, Tunisia, Turkey, Uruguay, Vietnam, the Yemen and Yugoslavia (which produced a similar weapon called the M65, qv).