Towed Howitzers

Army, Oct 2004

Designed for conditions encountered during the Vietnam conflict, the M102 105 mm Towed Howitzer was first fielded to 1-21 Field Artillery, 9th Light Infantry Division in Vietnam in 1966. It is a highly versatile weapon system with a maximum range of 11,500 meters.

Nearly one ton lighter than the World War II-era MlOlAl 105 mm towed howitzer (4,980 pounds) that it replaced, the M102 (3,338 pounds) proved to be a highly versatile weapon.

Most Ml 02 systems have been replaced by the M119A1/A2 105 mm towed howitzer. Over 200 remain in service with the Army National Guard (ARNG). In 2004, ARNG M102s were deployed to Iraq. There are 10 Army National Guard battalions that field the M102. Currently the Army is considering equipping active duty units with the M102.

The M119A1 105 mm Towed Howitzer was first issued to the U.S. Army's 7th Infantry Division (Light) in December 1989. Transportable by UH-60 helicopters, the lightweight, towed field artillery system (4,520 pounds including BII, 4,100 without) provided significantly greater range (14,000 meters standard, 19,500 high-explosive rocket-assisted) and lethality than the MlOlAl/M102 105 mm towed howitzers that it replaced in a variety of light units.

Based on the LH 8 British light gun, the M119Als provided to U.S. units were modified with U.S. fire control, a cannon assembly able to fire U.S. 105 mm ammunition (vice the British electrically fired Abbot ammunition) and the addition of brackets to incorporate a chronograph and battery computer system. A series of upgrades to the basic M119A1 has resulted in a redesignation of M119A2 for these modernized howitzers.

To provide even greater range and lethality for light-unit fire-support elements, the Army began fielding the M198 155 mm Towed Howitzer in early 1979. As a successor to the older M114A1 155 mm towed system, the 15,750-pound (original fielded weight) M198 provided a maximum range of 30 kilometers (with rocket-assisted projectiles) and the capability to fire a broader range of ammunition options than those available for 105 mm units.

Normally towed by a 5-ton truck, the M198 can also be moved by a CH-47D Chinook helicopter or Air Force assets, C-130 and larger.

The M777/M777A1 Lightweight 155 mm Howitzer (LW155) is a joint Marine Corps and Army program to replace the M198 155 mm towed howitzer. The LW155 will be a general support system for the Army's light units, and direct-support cannon fire-support system for the Stryker brigade combat team. It will be the sole howitzer in the Marine Corps.

Its key performance parameters are a howitzer weight of less than 10,000 pounds, emplacement time of two to three minutes and a displacement time of one to two minutes. The LW155 uses the M776 155 mm cannon, giving it a maximum firing range of approximately 30 kilometers with rocket-assisted projectiles and 24.7 kilometers with standard rounds. It has a maximum firing rate of four rounds per minute and a sustained rate of two rounds per minute.

The first engineering manufacturing and development (EMD) LWl 55 was delivered to the government in June 2000. A total of eight EMD and two pilot production howitzers have since been delivered and undergone technical tests.

After a joint Army-Marine operational assessment in 2002, in November 2002 the Marine Corps was given permission to begin low rate production of the basic M777 howitzer. The first production howitzer was delivered in February 2004. The USMC will begin fielding a total of 94 M777s in January 2005.

The M777E1 is a test version of the M777 fitted with on-board electronics, giving it similar self-locating, self-laying and digital communications as the M109A6 Paladin. Following a joint operational test in the second half of 2004, both the Army and Marine Corps will begin production and fielding of this variant, then designated M777A1. The 94 USMC M777s will also be upgraded to the Al configuration. The M777A1 will be the first howitzer capable of firing the XM982 Excalibur projectile described below. The Army first unit equipped is scheduled to be the 2-11 Field Artillery in the 2nd Brigade (Stryker brigade combat team), 25th Infantry Division (Light) in late 2006.

The XM982 Excalibur is a 155 mm precision-guided cannon munition that will be fired from the NLOS-C, M777A1 and M109A6 Paladin. It will be GPS-guided and IMU-aided, and require no designation. Its jam-resistant global positioning system (GPS) receiver and inertial measurement unit (IMU) guidance package will enable the projectile to be delivered with a high degree of precision that is independent of range (10 meters CEP unjammed and 20 meters CEP in a jammed environment). Excalibur will follow a ballistic ascending branch of its trajectory. Once it has reached apogee and has acquired GPS, it will then glide along a nonballistic flight path to the target area. This gliding action, combined with the effect of its base bleed design, will allow Excalibur to achieve extended range over conventional munitions (35-40 kilometers maximum range). Once Excalibur reaches the target area, it will then execute a very steep (near 90 degree) terminal trajectory and attack the target from the top. It is this steep terminal trajectory that will make Excalibur superior for use in complex and urban terrain.