The M198 howitzer
is a medium-sized, towed artillery
Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...
piece, developed for service with the United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
and Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...
. It was commissioned to be a lightweight replacement for the WWII era M114 155mm howitzer. It was designed and prototyped at the Rock Island Arsenal
The Rock Island Arsenal comprises , located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It lies within the state of Illinois. The island was originally established as a government site in 1816, with...
in 1969 with firing tests beginning in 1970 and went in to full production there in 1978. It entered service in 1979 and since then 1,600 units have been produced and put into operation.
The M198 is being replaced in US and Australian service by the BAE M777 howitzer
The M777 howitzer is a towed 155 mm artillery piece, successor to the M198 howitzer in the United States Marine Corps and United States Army. The M777 is also used by the Canadian Army, and has been in action in Afghanistan since February 2006 along with the associated GPS-guided Excalibur...
, with deliveries underway.
The M198 155mm howitzer weighs under 16,000 pounds allowing it to be dropped by parachute
A parachute is a device used to slow the motion of an object through an atmosphere by creating drag, or in the case of ram-air parachutes, aerodynamic lift. Parachutes are usually made out of light, strong cloth, originally silk, now most commonly nylon...
or transported by a CH-53E Super Stallion
The Sikorsky CH-53E Super Stallion is the largest and heaviest helicopter in the United States military. It was developed from the CH-53 Sea Stallion, mainly by adding a third engine, a seventh blade to the main rotor and canting the tail rotor 20 degrees. Sailors commonly refer to the Super...
or CH-47 Chinook
The Boeing CH-47 Chinook is an American twin-engine, tandem rotor heavy-lift helicopter. Its top speed of 170 knots is faster than contemporary utility and attack helicopters of the 1960s...
. The M198 is a towed howitzer that is transported tail first, with the cannon resting above the weapon's wheels. When firing, the weapon is lowered onto its baseplate rather than being anchored to the ground allowing for rapid emplacement. The breech is operated manually via a screw type mechanism that rests low in an ergonomic position. The M198 fires non-fixed ammunition and can be loaded with a variety of propellants and projectiles. The effective range 18,100 meters when firing standard projectiles and it increases to 30,000 meters when firing rocket assisted projectiles. With the 52-caliber modification the range can surpass 40,000 meters. The weapon system requires a crew of 11 and is capable of firing at a maximum rate of four rounds per minute, two sustained.
The M198 is deployed in separate corps
A corps is either a large formation, or an administrative grouping of troops within an armed force with a common function such as Artillery or Signals representing an arm of service...
- and army-level field artillery units, as well as in artillery battalion
A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...
s of light
Traditionally light infantry were soldiers whose job was to provide a skirmishing screen ahead of the main body of infantry, harassing and delaying the enemy advance. Light infantry was distinct from medium, heavy or line infantry. Heavy infantry were dedicated primarily to fighting in tight...
Airborne forces are military units, usually light infantry, set up to be moved by aircraft and 'dropped' into battle. Thus they can be placed behind enemy lines, and have an ability to deploy almost anywhere with little warning...
divisions. It also provides field artillery fire support for all Marine Air-Ground Task Force
The Marine Air-Ground Task Force is a term used by the United States Marine Corps to describe the principal organization for all missions across the range of military operations. MAGTFs are a balanced air-ground, combined arms task organization of Marine Corps forces under a single commander that...
High Explosive (HE)|M-107]] NC/DC): Explosive Composition B
Composition B, colloquially "comp B", is an explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades, sticky bombs and various other munitions...
material packed into a thick,internally-scored shell which causes a large blast and sends razor-sharp fragments at extreme velocities (5,000–6,000 meters per second). The kill zone is approximately a radius of 50 meters and casualty radius is 100 meters. The Marine Corps and US Army also uses the M795
High Explosive round.
Rocket Assisted Projectile
A Rocket Assisted Projectile is an artillery or cannon round incorporating a rocket motor for independent propulsion. This grants the projectile both greater speed and range than an ordinary shell, which is propelled only by the ballistic force of the gun's exploding charge...
- A rocket-assisted HE (also known as H.E.R.A.) round that adds to the maximum range of the normal HE. For the 155 mm RAP round, max range is 30.1 kilometres (18.7 mi).
White Phosphorus (WP)
- A base-ejecting projectile which can come in two versions: felt-wedge and standard. White phosphorus
White phosphorus is a material made from a common allotrope of the chemical element phosphorus that is used in smoke, tracer, illumination and incendiary munitions. Other common names include WP, and the slang term "Willie Pete," which is dated from its use in Vietnam, and is still sometimes used...
smoke is used to start fires, burn a target, or to create smoke which is useful in concealing the movements of friendly units.
- Illumination projectiles are base-ejecting rounds which deploy a bright parachute flare ideally 600 meters above the ground and illuminates an area of approximately 1 grid square (1,000,000 square meters). Illumination rounds are often used in conjunction with HE rounds, to illuminate the target area so that HE rounds can be fired more effectively. Illumination rounds can also be used during the daytime to mark targets for aircraft. The M485 Illumination round burns for 120 seconds.
Dual-Purpose Improved Conventional Munition (DPICM)
- A base-ejecting projectile which drops 88 bomblets
A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller sub-munitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill enemy personnel and destroy vehicles...
above a target. Each bomblet has a shaped-charge munition capable of penetrating two inches of solid steel as well as a fragmentation casing which is effective against infantry in the open. The DPICM round is effective against armored vehicles
Armoured warfare or tank warfare is the use of armoured fighting vehicles in modern warfare. It is a major component of modern methods of war....
, even tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
s (since the deck armor is usually the thinnest on the vehicle), and is also extremely useful against entrenched infantry in positions with overhead cover.
Area Denial Artillery Munition System (ADAMS)
- An artillery round that releases anti-personnel mines. These mines eject tripwires to act as booby traps, and when triggered are launched upward before exploding. They are designed to self-destruct after a pre-determined period of time.
Remote Anti Armor Mine System (RAAMS)
- An artillery round that releases anti-armor mines, usually used along with ADAMS rounds to prevent the antitank mines from being removed. Designed to self-destruct after a pre-determined period of time.
The M712 Copperhead is a caliber cannon-launched, fin-stabilized, terminally laser guided, explosive projectile intended to engage hard point targets such as tanks, self-propelled howitzers or other high-value targets. It may be fired from different artillery pieces, such as the M114, M109 and...
- An artillery launched guided high explosive munition which is used for very precise targeting of high value targets such as tanks and fortifications. It requires the target be designated with a laser designator system. This round is currently no longer produced or used by the US military.
Sense and Destroy ARMor (SADARM)
- An experimental munition which is fired in the general direction of an enemy vehicle. The shell activates at a certain point in time ejecting a parachute and then guides itself to the nearest vehicle.
BAE Systems plc is a British multinational defence, security and aerospace company headquartered in London, United Kingdom, that has global interests, particularly in North America through its subsidiary BAE Systems Inc. BAE is among the world's largest military contractors; in 2009 it was the...
has won the contract to replace the M-198 in the US Army and Marine Corps with its M777 155 mm/39 cal towed howitzer, which weighs less than 11,000 lb/4,220 kg.
120 howitzers to be supplied from U.S. 57–60 26+
A howitzer is a type of artillery piece characterized by a relatively short barrel and the use of comparatively small propellant charges to propel projectiles at relatively high trajectories, with a steep angle of descent...
- List of artillery
- List of crew served weapons of the US Armed Forces