The M198 is a medium-sized, towed

155 mm The 155 mm calibre is widely used for artillery guns. Land warfare Historic calibres France - 1874 The caliber originated in France after the Franco-Prussian War (1870–1871). A French artillery committee met on 2 February 1874 to dis ...

artillery Artillery consists of ranged weapons that launch Ammunition, munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and l ...

piece, developed for service with the

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

and

Marine Corps Marines (or naval infantry) are military personnel generally trained to operate on both land and sea, with a particular focus on amphibious warfare. Historically, the main tasks undertaken by marines have included raiding ashore (often in supp ...

. It was commissioned to be a replacement for the World War II-era

M114 155 mm howitzer The 155 mm Howitzer M114 is a towed howitzer developed and used by the United States Army. It was first produced in 1941 as a medium artillery piece under the designation of 155 mm Howitzer M1. It saw service with the US Army during World W ...

. It was designed and prototyped at the

Rock Island Arsenal The Rock Island Arsenal comprises 946 acres (383 ha) and is located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It is home to the United Stat ...

in 1969 with firing tests beginning in 1970 and went into full production there in 1978. It entered service in 1979 and since then 1,600 units have been produced. The M198 was replaced in US and Australian service by the

M777 howitzer The M777 howitzer is a British towed 155 mm artillery piece in the howitzer class. It is used by the ground forces of Australia, Canada, Colombia, India, Saudi Arabia, Ukraine, and the United States. It was first used in combat during the Wa ...

Description

The M198 155 mm

howitzer The howitzer () is an artillery weapon that falls between a cannon (or field gun) and a mortar. It is capable of both low angle fire like a field gun and high angle fire like a mortar, given the distinction between low and high angle fire break ...

weighs less than , allowing it to be dropped by

parachute A parachute is a device designed to slow an object's descent through an atmosphere by creating Drag (physics), drag or aerodynamic Lift (force), lift. It is primarily used to safely support people exiting aircraft at height, but also serves va ...

or transported by a

CH-53E Super Stallion The Sikorsky CH-53E Super Stallion is a heavy lift helicopter operated by the United States military. As the Sikorsky S-80, it was developed from the CH-53 Sea Stallion, mainly by adding a third engine, adding a seventh blade to the main rotor ...

CH-47 Chinook The Boeing CH-47 Chinook is a tandem-rotor helicopter originally developed by American rotorcraft company Piasecki Helicopter, Vertol and now manufactured by Boeing Defense, Space & Security. The Chinook is a Military transport helicopter, heav ...

. The M198 is towed by a truck that is used to carry the nine person crew with supplies and ammunition; it is transported tail first. The gun tube can be rotated over the howitzer's trail legs to reduce its length, though this requires removal of the

muzzle brake A muzzle brake or recoil compensator is a device connected to, or a feature integral (ported barrel) to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter re ...

, or left in the firing position for faster deployment. When firing, the weapon is lowered onto its baseplate rather than 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 separate-loading (non-fixed or semi-fixed) ammunition and can be loaded with a variety of propellants and projectiles. The effective range is when firing standard projectiles, which increases to when firing

rocket-assisted projectile A rocket-assisted projectile (RAP) is a cannon, howitzer, Mortar (weapon), mortar, or recoilless rifle round incorporating a rocket motor for independent propulsion. This gives the projectile greater speed and range than a non-assisted Ballistics ...

s and guided ammunition. With the 52-caliber modification, the range can surpass . The weapon system requires a crew of nine, and is capable of firing at a maximum rate of four rounds per minute, two sustained. The M198 was deployed in separate

corps Corps (; plural ''corps'' ; from French , from the Latin "body") is a term used for several different kinds of organization. A military innovation by Napoleon I, the formation was formally introduced March 1, 1800, when Napoleon ordered Gener ...

- and

army An army, ground force or land force is an armed force that fights primarily on land. In the broadest sense, it is the land-based military branch, service branch or armed service of a nation or country. It may also include aviation assets by ...

-level field artillery units, as well as in artillery

battalion A battalion is a military unit, typically consisting of up to one thousand soldiers. A battalion is commanded by a lieutenant colonel and subdivided into several Company (military unit), companies, each typically commanded by a Major (rank), ...

s of

light Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...

and airborne divisions. It provided field artillery fire support for all

Marine Air-Ground Task Force Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine current power * Marine debris * Marine energy * Marine habitats * ...

organizations until the adoption of the M777 howitzer.

Ammunition types

;High explosive (HE) :( M-107 NC/DC): Explosive

Composition B Composition B (Comp B), also known as Hexotol and Hexolite (among others), is a high explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenade ...

material packed into a thick, internally scored shell which causes a large blast and sends razor-sharp fragments at extreme velocities (). The kill zone has an approximate radius of , and the

casualty radius Casualty may refer to: *Casualty (person), a person who is killed or rendered unfit for service in a war or natural disaster **Civilian casualty, a non-combatant killed or injured in warfare * The emergency department of a hospital, also known as ...

is . The Marine Corps and US Army also uses the

M795 The M795 155 mm projectile is the US Army and US Marine Corps' standard 155 mm High Explosive (HE) projectile for howitzers. It is a bursting round with fragmentation and blast effects. The M795 is designed to be more lethal and have a lo ...

High Explosive round. ;Rocket-assisted projectile (RAP) : A high-explosive rocket-assisted (HERA)

M549 The M549 is a high-explosive rocket-assisted (HERA) 155 mm howitzer round developed for use by the US military in order to add additional range to standard howitzers, with a maximum range from a M198 howitzer. The projectile has two distinctive ...

round with a greater range than the normal HE. The maximum range is . ;White phosphorus : A base-ejecting projectile which can come in two versions: felt-wedge and standard.

White phosphorus White phosphorus, yellow phosphorus, or simply tetraphosphorus (P4) is an allotrope of phosphorus. It is a translucent waxy solid that quickly yellows in light (due to its photochemical conversion into red phosphorus), and impure white phospho ...

smoke is used to start fires, burn a target, or to create smoke which is useful in concealing the movements of friendly units. ;Illumination : Illumination projectiles are base-ejecting rounds which deploy a bright parachute flare ideally above the ground and illuminate an area of approximately 1 grid square (). 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 A dual-purpose improved conventional munition (DPICM) is an artillery or surface-to-surface missile warhead designed to burst into submunitions at an optimum altitude and distance from the desired target for dense area coverage. The submunitions ...

(DPICM) : A base-ejecting projectile that drops 88 bomblets 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 Military vehicles are commonly armoured (or armored; see spelling differences) to withstand the impact of shrapnel, bullets, shells, rockets, and missiles, protecting the personnel inside from enemy fire. Such vehicles include armoured fighti ...

, even

tank A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and battlefield mobility provided by tracks and a powerful engine; ...

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 predetermined period. ;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 predetermined period. ; Copperhead : An artillery launched guided high-explosive munition used for very precise targeting of high-value targets such as tanks and bunkers. No longer produced or used by the US military, it required the target to be designated with a laser designator system. ; Sense and Destroy ARMor (SADARM) : An experimental munition 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. ; XM454 AFAP (artillery fired atomic projectile) (W48) : The XM454 AFAP (W48) nuclear artillery shell had a 155mm caliber and an explosive yield of only . All units were retired from service in 1992.

Replacement

BAE Systems BAE Systems plc is a British Multinational corporation, multinational Aerospace industry, aerospace, military technology, military and information security company, based in London. It is the largest manufacturer in Britain as of 2017. It is ...

won the contract to replace the M198 in the US Army and Marine Corps with its

M777 The M777 howitzer is a British towed artillery, towed 155 mm artillery piece in the howitzer class. It is used by the Australian Army, ground forces of Australia, Canadian Army, Canada, Colombia, Indian Army, India, Saudi Arabian Army, Saudi Ar ...

155 mm/39 cal towed howitzer, which weighs less than . It was introduced in 2005.

Operators

Current operators

* : 28 in service with the

Royal Bahraini Army The Royal Bahraini Army is the ground force component of the Bahrain Defence Force. The army's current strength is 20,000 personnel. It is headed by Lieutenant General Khalifa bin Abdullah Al-Khalifa. History Bahraini ground troops took part in ...

* : 10 * : 12 * : 4 * : 60 ** * : 218 * : 35 units. * : 148 * : 60 in service with the

Saudi Arabian Army The Saudi Arabian Army (), officially the Royal Saudi Land Forces (), is the principal land warfare branch of the Armed Forces of Saudi Arabia. It is part of the Saudi Ministry of Defense, which is one of the two military departments of the gove ...

and 58 in service with the

Saudi Arabian National Guard The Saudi Arabian National Guard (SANG), also known as the White Army, is one of the three major branches of the military forces of the Kingdom of Saudi Arabia. The national guard is under the administrative control of the Ministry of National ...

* : 55 * : 118 units in service with

Royal Thai Army The Royal Thai Army or RTA (; ) is the army of Thailand and the oldest and largest branch of the Royal Thai Armed Forces. History Origin The Royal Thai Army is responsible for protecting the kingdom's sovereignty. The army was formed in 187 ...

Former operators

* : 36 * : 52 captured. Some were taken back while other were destroyed by air strikes. * : 18 used during the

Siad Barre Mohammed Siad Barre (, Osmanya script: , ''Muhammad Ziād Barīy''; 6 October 1919 – 2 January 1995) was a Somali military officer, politician, and revolutionary who served as the third president of Somalia from 21 October 1969 to 26 Janu ...

era * : 358

Bibliography

* * *

References

External links

{{Commons category, M198 howitzer
Weapon Profile
as part of ''The Whirlwind War The United States Army in Operations DESERT SHIELD and DESERT STORM'' a publication of the

United States Army Center of Military History The United States Army Center of Military History (CMH) is a directorate within the United States Army Training and Doctrine Command. The Institute of Heraldry remains within the Office of the Administrative Assistant to the Secretary of the Arm ...

www.fas.org – M198 Towed Howitzer

Development prototype XM198 (U.S. Army photo)
155 mm artillery Cold War artillery of the United States Field artillery Artillery of the United States United States Marine Corps equipment Howitzers Military equipment introduced in the 1970s