Gama Goat
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The Gama Goat was a six-wheel-drive semi-amphibious off-road vehicle originally developed for use by the US Military for the war in Southeast Asia. It was famous for an articulated body, which allowed it to travel over exceptionally rough terrain and for a unique four wheel steering arrangement with the front and rear wheels turning in opposite directions.
The nickname came from two sources, "Gama" from the name of the inventor of its powered articulated joint, Roger Gamount, and "Goat" for its mountain goat-like off-road ability. Its military designation was M561, 6x6 tactical 1.5 ton truck. There was also an ambulance version known as the M792.
It was 226.6 in (5.76 m) long, had a curb weight of 7,300 lb (3,300 kg) and a payload capacity of 2,900 lb (1,300 kg) and was powered by a Detroit Diesel #3-53 three cylinder, two stroke engine that produced 103 hp (77 kW) at 2,800 rpm with a 159.3 in³ (2,610 cc) displacement. It could travel at 55 mph (90 km/h) on paved surfaces and traverse almost any terrain. It was designed to be air-transportable and droppable by parachute.
While technically listed as amphibious, the swimming capability was limited to smooth water crossings of ponds, canals and streams due to low freeboard and the lack of a propeller. Propulsion in the water was supplied by the six spinning wheels. Bilge pumps were standard equipment. Some models had extra equipment installed which made them non-swimmable, such as heavy-duty winches or radar gear.
The concept for the vehicle came when the French Army reported that the US Army trucks provided to them were woefully inadequate for the terrain in Vietnam. In 1959, ARPA funded a research project called Project Agile to develop a new tactical truck for the Southeast Asia theatre, as well as other projects of interest to the then looming Vietnam War.
Several companies bid for the contract including Clark, General Motors and LeTourneau, but the contract was given to Ling Temco Vought (LTV)aerospace, best known for their A-7 Corsair II aircraft. Final construction was by Consolidated Diesel Electric Company (CONDEC) at their factory in Charlotte, North Carolina.
Overall, some 15,274 Gama Goats were built at a cost of $8,000 each. This was considered quite high at the time, and while the Gama Goat had exceptional off road ability its quirky steering made it hard to handle on pavement combined with its tendency to founder in amphibious operations meant it required special training to operate. This meant it could not be the "general purpose" vehicle the Army had hoped for, and production was halted after the original contract expired. This is somewhat ironic, as some claim the problems were largely due to cost-cutting modifications made at the request of the U.S. Army. The Gama Goat came with a warning that hearing protection was mandatory during use. The 'goat is prized among military vehicle collectors because it is so unique and in short supply.
The vehicle was replaced by the CUCV and HMMWV, or HummVee, which are still in service.
[edit] Specifications
Dimensions:
- Length 226.6 in (5.76 m)
- Width 83.80 in (2.13 m)
- Height 90.80 in (2.31 m)
- Reducible height 65 in (1.65 m)
- Tread 72 in (1.83 m)
- Ground clearance 15 in (380 mm)
- Pintle height 22 in (560 mm)
Articulation:
- Roll at center axle ± 15 degrees
- Roll at rear axle ± 30 degrees
- Pitch at rear axle ± 40 degrees
- Wall climb (vertical) 18 in (460 mm)
- Angle of approach 62 degrees
- Angle of departure 45 degrees
- Hump angle 140 degrees
Suspension:
- Front and Rear Independent coil and springs at each wheel.
- Center Single leaf spring and swing axle.
Steering System:
- Type Mechanical front and rear simultaneous operated.
- Steering ratio 24:1
- Turning ratio 29 ft (8.8 m)
Variants:
- Communications
- Mortar
- Radar (mortar / artillery system)
- Personnel Carrier
- Radar (FAAR System)
- Ambulance (M792)
