USMC M107 175mm Self-Propelled Gun

The M107 175mm self-propelled Gun was largely deployed in NATO areas and its ammunition was commonly used throughout NATO forces. Designed to be part of a common family of weapons utilising the same chassis components, the M107 and M110 were essentially the same vehicle mounting different barrels. These guns fired an HE shell weighing 66.6 kilograms at a muzzle velocity of 914 meters per second.

The M107 self-propelled 175-mm. gun and the M110 8-inch howitzer had identical carriages but different tubes. The 175-mm. gun fired a 174-pound projectile almost 33 kilometers. This impressive range made it a valuable weapon for providing an umbrella of protection over large areas. The 8-inch howitzer fired a 200-pound projectile almost 17 kilometers, plus being the most accurate weapon in the field artillery. The 8-inch howitzer was found with most division artilleries, and both the 8-inch howitzer and 175-mm. gun were with field force artillery. At field force the proportion of 8-inch and 175-mm. weapons varied. Since the weapons had identical carriages, the common practice was to install those tubes that best met the current tactical needs. One day a battery might be 175­mm.; a few days later it might be half 175-mm. and half 8-inch.

The M107 was used extensively in Vietnam to provide long range firesupport (being able to fire more than 30 km) and took part in numerous cross-DMZ duels with NVA guns. Though withdrawn from American service, vehicles of this type remain in service in the militaries of some other countries. The M107 was exported in Germany, in South Korea, in Spain, in Greece, in Holland, in Iran, in Israel, in Italy, with United Kingdom and in Turkey. In the majority of these countries they are converted besides towards M110A2.

During the 1950s the standard of US Army motorized howitzer of 203mm was the M55, based on the chasis and the turret of the M53 self-propelled howitzer of 155mm gun. The weight of the machines of this family (±40t) prohibited, however, their air transport, while their gasonline engines confered a range limit of approximately 260 km.

This brought the Army to build a new series of self-propelled guns, lighter and transportable by air, derive from the same frame and some same mounting. Pacific Car and Foundry company developed a number of prototypes. The self-propelled guns T235 of 175mm and T245 of 155mm, and motorized howitzer T236 of 203mm. The T235 and T236 were driven by a diesel engine and manufactured in series under the respective references M107 and M110.

A certain number of tank recovery vehicles were developed on the frame of M107, but only the light vehicle M578 is used at the present time. The T120E1 was subsequently standardized as the M578. It equiped many countries, in particular the United States. The T119 and T121 unarmored recovery vehicles and the 155mm T245 were not developed further.

The first M107 series were manufactured by Pacific Car and Foundry Company in 1962. The first battalion was formed in 1983 beginning with Fort Still, bases US Field Artillery. Two other firms also produced of M107: FMC, between 1965 and 1980, Bowen-McLaughlin-York. The Army deployed the M107 on level of army corps within battalion equip of twelve guns each, but all these weapon were replaced by the M110Aé of 203mm which fired a HE projectile with propulsion additional of with a range exceeding 29 KM.

The 175 mm gun points elevation from - 2° to + 65° and in azimuth on 30° on the right and on the left. These operations are assisted, with hand drive operations of help. The only projectile used by the American army is HE M437A1 or M437A2 whose range is approximately 32.7 KM. Israelies employ special ammunition having a range close to 40.0 KM. the projectile normally weighs 66.78 kg, but a hydraulic device assembled to the back of the frame facilitates its loading: it raises it ground, positions it and pushes it in the cylinder head. The powder load is then set up and the shooting can start. M107 transports only two projectiles and their load. It is served by a crew of thirteen people, of which five only (pilot, head of tank, and three gunners) are on board. The others follow normally on board tracked M548 which contains the remainder of the ammunition. Certain country replaces it by trucks 6 X 6, whose possibilities any ground are however quite lower than that of the gun itself. M107 is equipped with infra-red equipment for the night vision.