M110A2 203mm howitzer.

Technical Data

• Armament

  The primary weapon system of the M110A2 is a 203 mm M201A1 howitzer mounted on the M158 cradle. It is a manually loaded, separate-loading artillery system that fires high-explosive and specialized munitions. The gun is fully traversable 30 degrees left and right and elevates between -2 and +65 degrees. Traverse and elevation are hydraulically powered, with manual backup controls for emergency operation.

  Ammunition types compatible with the M110A2 include several conventional and submunition rounds. The M106 high-explosive projectile weighs 92.53 kilograms and has a maximum muzzle velocity of 711 meters per second, delivering a range of up to 22,900 meters. The M404 Improved Conventional Munition carries 104 anti-personnel grenades and reaches up to 17,200 meters. The M509A1 round increases submunition load to 180 anti-personnel and anti-materiel grenades and also ranges to 22,900 meters. The most extended range is achieved using the M650 High-Explosive Rocket Assisted projectile, which reaches up to 30,000 meters when fired with the M118A1 charge 9 propellant.

  Only two rounds are carried onboard the M110A2 due to space and weight constraints. The majority of ammunition is transported in the M548 cargo vehicle. The typical rate of fire is one round every two minutes, though a maximum rate of two rounds per minute is achievable for short periods during intense fire missions. Rounds are loaded using a rammer-loader mechanism mounted on the rear left of the chassis. This system is powered by the vehicle’s hydraulic system but includes hand cranks for manual operation in case of hydraulic failure.

• Design and protection

  The M110A2 is built on a robust all-welded hull constructed from high-tensile alloy steel, identical in design to the M107 175 mm gun system. Its layout positions the driver in the front-left of the hull under armor, while the engine and transmission are located to his immediate right. The driver is the only member of the crew protected by armor and operates from a single-piece hatch fitted with three M17 periscopes. The central periscope can be swapped with a passive night vision device to allow nighttime maneuvering.

  The rear section of the vehicle consists of an open-topped fighting compartment where the main 203 mm howitzer is mounted. This area is manned by the gun commander, gunner, and two loaders. These crew members are exposed to the environment and battlefield threats, relying on the vehicle’s range and tactical positioning rather than physical protection. The open design facilitates fast access to the weapon and ease of operation for large, separate-loading ammunition.

  A total of five crew members operate directly on the vehicle, with the remaining eight crew members stationed in the M548 tracked cargo carrier that accompanies the M110A2. This support vehicle not only carries ammunition but also provides logistical and operational assistance, including projectile handling and coordination of sustained fire missions.

  Gun operation is highly manual, requiring coordination between the gunner, loaders, and rammer operator. The commander oversees all fire missions, relays target data from forward observers or fire direction centers, and ensures firing parameters are correctly applied. The gunner is responsible for laying the gun using optical instruments, while the loaders operate the hydraulic or manual ramming system. Team efficiency is essential for maintaining the M110A2’s firing tempo, particularly during high-intensity operations.

• Mobility

  The M110A2 is powered by a Detroit Diesel 8V-71T turbocharged, liquid-cooled, two-stroke 8-cylinder diesel engine, delivering 405 brake horsepower at 2,300 rpm. This powerplant is mated to an Allison XTG-411-2A cross-drive transmission, which includes four forward and two reverse gears. Together, they provide reliable traction and mechanical robustness, critical for supporting the vehicle's 28-ton combat weight across rugged terrain.

  The M110A2 achieves a top road speed of approximately 54.7 kilometers per hour and has an operational cruising range of up to 523 kilometers on a full tank of 984 liters. Fuel consumption averages 1.88 liters per kilometer. The howitzer is capable of negotiating a 60 percent gradient, fording water up to 1.066 meters in depth, and traversing trenches measuring up to 1.905 meters wide. Its maximum vertical obstacle clearance is approximately 1.016 meters.

  The suspension system includes five dual rubber-tired road wheels on each side. Each road wheel is connected to a hydraulic shock absorber and bump stop, which serves a dual purpose to dampen movement during cross-country travel and to lock the suspension when firing. This locking mechanism transfers recoil force directly into the ground, stabilizing the weapon and preventing excessive stress on the chassis. The fifth road wheel functions as the idler, while the drive sprocket is positioned at the front of the hull. There are no track return rollers. The tracks are of the single-pin type with removable rubber pads, optimized for cross-country mobility in varied terrain conditions.

• Combat Equipment

  The fire control system of the M110A2 is entirely optical and manual. For indirect fire, the vehicle is equipped with the M115 panoramic telescope, which offers a magnification of four times and a 10-degree field of view. For direct fire, it uses the M116C telescope with three times magnification and a 13-degree field of view. Additional instruments include the M15 elevation quadrant and the M1A1 gunner’s quadrant.

  The gun’s traverse and elevation are hydraulically actuated, but manual controls are included for redundancy. The vehicle has night vision equipment for the driver but lacks any integrated radar, computerized fire control, or automated loading systems. There is no smoke-laying equipment and no internal NBC filtration, placing reliance on standoff tactics and supporting logistics for survivability and endurance in the field.