Tube Artillery Systems
(Source: TM 9-500, Data Sheets for Ordnance Type Materiel, September 1962)
Howitzer, Heavy, Self-Propelled: Full Tracked, 8-inch M55 (T108)
See below for general description (TM 9-500)

HOWITZER, HEAVY, SELF-PROPELLED, FULL TRACKED: 8-inch, M55 (T108), is a lightly armored, front sprocket-driven, full-track-laying vehicle. The M55 provides mobility for the 8-inch howitzer and crew protection in offensive combat. The vehicle is powered by a 90-degree, V-type, air-cooled engine. Power is transmitted to the final drives through a cross-drive transmission, which is a combined transmission, differential, and steering unit.

The vehicle utilizes the torsion bar suspension system, incorporating seven individually sprung road wheels on each side, shock absorbers, track support rollers, and tracks. Trailer idler wheels, mounted on eccentric shafts, maintain constant tension on the tracks when the vehicle is in motion.

The vehicle hull is divided into four compartments; engine, fuel tank, turret support, and stowage. The engine compartment is decked over to provide protection against enemy fire and other elements. The turret support compartment mounts the turret, which houses the CANNON, 8-INCH HOWITZER: M47: MOUNT, GUN: 8-inch howitzer, M86*. The turret also houses the driving controls.