The United States Army's M198 towed 155-mm Field Artillery Howitzer is a medium weight weapon weighing approximately 16,000 pounds. Operated by an 11 man crew, this weapon is designed to provide general support and direct support artillery fire for infantry and air assault divisions and in the corps general support battalions. It is also used to increase light infantry division capabilities as required by specific missions. The M198 is used by both the U.S. Army and the U.S. Marine corps units, active and reserve.
Currently there are four methods of transporting the M198 howitzer; air, ground, water, and rail. The principal method of transport is by ground. Because of its high tongue weight (4,200 lbs. In the stowed configuration) the M198 howitzer must be towed by a relatively large vehicle, such as a 21/2 ton or a 5-ton cargo truck. The 5 ton cargo truck is assigned to the artillery unit and transports the unit personnel, their ammunition, equipment, and the M198 Howitzer in a stowed or towed A-frame position configuration. The 5-ton cargo truck is equipped with a rear pintle hook that attaches to the M198 howitzer's lunette (a ring in the trail plate of the towed howitzer, that is used to attach the howitzer to the pintle of the 5-ton cargo truck). Towing in the towed A-Frame configuration is recommended in tactical situations because towing in the stowed configuration usually requires removal of the muzzle brake.
During combat operations, it may be necessary for the commander to quickly move his fire support assets forward to engage targets that are beyond the weapons range capabilities and then quickly move them back to support the close battle. To conduct these missions, the commander would use the heavy lift assets within the Corps to airlift the howitzers on an artillery raid.
The primary method of air transport of the howitzer is the CH-47D, or larger, heavy lift helicopter. The howitzer is externally rigged for air transport with lifting hardware attached to the four lifing eyes. The howitzer is in the A-frame configuration during air transport. The crew, ammunition, and equipment are secured within the helicopter. Once the aircraft reaches its destination, it drops off the howitzer, crew, ammo, and equipment and then departs. There currently is no method of moving the howitzer once it has been positioned by the helicopter, since the 5-ton truck is not air-liftable.
To meet the increased requirement for responsiveness and survivability demanded by the broad range of future combat missions, towed howitzers must have the capability to be rapidly and accurately emplaced, conduct fire missions, and move to a new location.