M109A6 Howitzer

M109 Howitzer
M109A6
Type	Self-propelled gun
Place of origin	United States
Service history
Wars	Vietnam War Yom Kippur War Iran–Iraq War Western Sahara War Persian Gulf War Iraq War Iraqi Civil War (2014–present) Yemeni Civil War (2015-present), Saudi Arabian-led intervention in Yemen Syrian Civil War
Specifications
Weight	27.5 tons
Length	30 ft (9.1 m)
Width	10 ft 4 in (3.15 m)
Height	10 ft 8 in (3.25 m)
Crew	6 (2 Loaders, Gunner, Assistant Gunner, Commander, Driver)
Shell	separate loading, bagged charge
Caliber	155 mm L/39 caliber
Breech	interrupted screw
Traverse	360°
Rate of fire	Maximum: 4 rpm Sustained: 1 rpm
Effective firing range	Conventional: 18 km (11 mi) RAP: 30 km (19 mi)
Main armament	M126 155 mm Howitzer
Secondary armament	.50 caliber (12.7 mm) M2 machine gun
Engine	Detroit Diesel 8V71T 450 hp (335.56 kW)
Power/weight	18.7 hp/t
Suspension	torsion-bar
Operational range	216 mi (350 km)
Speed	35 mph (56 km/h)

The M109 is an American 155 mm turreted self-propelled howitzer, first introduced in the early 1960s. It has been upgraded a number of times, most recently to the M109A7. The M109 family is the most common western indirect-fire support weapon of maneuver brigades of armored and mechanized infantry divisions.

The M109 has a crew of six: the section chief, the driver, the gunner, the assistant gunner and two ammunition handlers. The gunner aims the cannon left or right (deflection), the assistant gunner aims the cannon up and down (quadrant). The M109A6 Paladin needs only a crew of four: the commander, driver, gunner and an ammunition loader.

The British Army replaced its M109s with the AS-90. Several European armed forces have or are currently replacing older M109s with the German PzH 2000. Upgrades to the M109 were introduced by the U.S. (see variants below) and by Switzerland (KAWEST). With the cancellation of the U.S. Crusader and Non-Line-of-Sight Cannon, the M109A6 ("Paladin") will remain the principal self-propelled howitzer for the U.S. for the foreseeable future.

The M109 was the medium variant of a U.S. program to adopt a common chassis for its self-propelled artillery units. The light version, the M108 Howitzer, was phased out during the Vietnam War, but many were rebuilt as M109s.

The M109 saw its combat debut in Vietnam. Israel used the M109 against Egypt in the 1973 Yom Kippur War and in the 1982 and 2006 Lebanon Wars. Iran used the M109 in the Iran–Iraq War in the 1980s. The M109 saw service with the British, Egyptian and Saudi Arabian Armies in the 1991 Gulf War. The M109 also saw service with the U.S. Army in the Gulf War, as well as in the Iraq War from 2003-2011.