the M107 and M110 use the same drive train components as the M578 light recovery vehicle. In addition to its use in performing maintenance on the M107 and M110, and for recovery of damaged or inoperable vehicles, this vehicle has seen wide employment in a variety of engineering roles. Many of the M107s were rebuilt into the M110A2 configuration. Chassis Both the M107 and M110 are based on a common chassis, which features five road wheels on either side of the chassis, idler arms attached to torsion bars, tracks driven from the front by a 450 hp General Motors turbo supercharged diesel with the turbocharger connected to the supercharger by a steel pencil sized "quill" shaft. The engine and transmission are mounted in the front right, with the driver to its left. The engine had an attached hydraulic pump used to traverse the turret with a manual backup hand crank. The hydraulic pump was sometimes improperly used to dig in the rear spade, resulting in damage to the hydraulic spade cylinders after the first round was fired. The manual backup was used to lay the gun, since the hydraulic control was too coarse. The primary purpose of the hydraulic pump was putting the barrel into battery, ramming ammunition and charges, raising or lowering the rear spade, rapid coarse deflection adjustment by the gunner and rapid coarse elevation adjustments by the assistant gunner. Defensive capabilities The M107/M110 chassis only provides protection to the driver, with 13mm of aluminum armor sufficient to block only small arms and shell splinters. Later on, Kevlar shields were often provided to M107 units for additional protection, but due to the unwieldiness of their use, these were often kept stowed on the sides of the vehicle or even left behind before deployment in the field. Key recognition features Long thin barrel without a fume extractor or muzzle brake. Gun is in an unprotected mount towards the rear of the hull with a large spade at the rear that is raised for traveling. Chassis is same as M110 203 mm self-propelled howitzer with five large road wheels on each side, a drive sprocket front wheel and has no track-return rollers. Operations and maintenance The M107 has a larger open working space than the closed space of tank-like self-propelled artillery such as the M109 howitzer. This allows for faster reload times and its high maneuvering speed and fast reload