Book Review: Detail in Action 39003: Gama Goat by David Doyle; Squadron Sig nal Publications 2013; 80 pp. with color and B&W photos; retail price US$26 .95 (hardback), US$18.95 (softback); ISBN 978-0-89747-735-2 (HB), 978-0-897
47-736-9 (SB)Advantages: first book of this curious vehicle and its entire developmental history; nicely presented format
Disadvantages: few photos of the Gama Goat as a shelter carrier, which was a primary task and role in divisional units of the US Army in the 1970s and 1980s
Rating: Highly Recommended
Recommendation: for all Cold War US softskin fans
There are times when an idea seems great on paper, tests well, but the rea lity of its execution leaves much to be desired. Such was the tale of the G ama Goat, a high-mobility amphibious truck rated at 1 1/4 short tons capaci ty in cross country driving.
The Gama Goat came out about the same time as the similar Swiss Metrac veh icle did, and both were designed to provide a high-mobility 6 x 6 vehicle. Each used the same basic design: a short 4 x 4 tractor unit with a permanen tly attached trailer with a driven axle. The body was designed to move in t wo directions only: up and down, to follow the terrain, and roll from side to side to accommodate bumps and obstructions. The body did not trail and w ould not turn to follow the tractor around corners (with the Gama Goat, if it did that it was grounds to immediately ?deadline? the vehicle as uns afe).
Robert Gamaunt, an American engineer, had been toying with a similar desig n since 1947, and in 1959 Vought Aviation took up the project to create a h igh-mobility 6 x 6 truck. The resulting prototype was all aluminum, powered by a 6-cylinder Chevrolet Corvair air-cooled engine, and weighed 3,000 pou nds. But while this eventually proved a successful design, it also had one of the key Achilles? heels of the ?Goat - the front and rear axles both steered, and keeping them in synch proved to be a nightmare.
The prototypes entered testing in 1961 and went more than 6,000 miles most ly trouble free. But after testing in Thailand in 1963 and demonstrating gr eat mobility in swamp and jungle terrain, the Army asked for some ?change s? to be made.
The Corvair engine was ditched, and after testing two engines the ?winne r? was a GM 3-53 diesel; a three-cylinder 103 HP wonder which on paper wa s half of the 6-53 engine then going into the M113A1. But it was a noisy, n asty engine which was mounted at head level behind the crew, and as such th e crew always had to wear protective ear muffs when driving it. It remained amphibious, but now weighed around 7,000 pounds. Between 1968 and 1972 15,
274 Gama Goats, officially the M561 6 x 6 1 1/4 Ton Truck, were built but C ONDEC.The ?Goat replaced the M37 3/4 ton trucks and the unhappy Jeep M715 seri es 1 1/4 tons trucks in many units, especially airborne, airmobile and ?l eg? infantry ones. In mechanized units the M561 was used either as an amb ulance or a shelter carrier, usually with an S-250 class shelter and set of generators towed on a trailer.
On a good day, the ?Goat could do about 45 mph on highways with a 1,800 pound shelter and 3,000 pound generator trailer towed behind it. It had ver y good off-road capability and could climb amazing obstacles, even with the trailer attached. But it was a maintenance nightmare.
Its steering gear rarely stayed aligned, and its ?easily serviced? out board brakes (they are on the outside of the wheel and not inside like 99% of other vehicles) were nearly impossible to properly bleed and adjust. Sin ce it was so articulated, it had around 22 universal joints, the failure of any one of which could bring the vehicle to a halt. If the emergency switc h inside the body was inoperative, the vehicle was theoretically deadlined (but with a shelter on the back ? which went empty nearly all the time wh en the vehicle was moving - who was going to crawl over and press it?) Also any damage to the tailgate meant it would not float (a moot point with a s helter and generator trailer anyway).
The ?Goat first began to be replaced by the M1008 CUCV family of Chevrol et 4 x 4 trucks as they were rated as 1 1/4 ton trucks, but suffered a loss of off-road mobility as a result. The ultimate replacement was the M996 Hi gh Mobility Military Vehicle series or Humvee.
Mr. Doyle has a superb collection of photographs and this book contains ar ound 150 of the best that illustrate the history of the ?Goat and its dif ferent versions. While it basically came with only two external options - a winch and a cold-weather hardtop, there were other detail differences such as aluminum or steel engine covers. While they came with troop seats for 1
0 and a canvas top, most units removed them (they also came with 12 life ja ckets for use in the water, but they disappeared very quickly among units w ith shelters).I was a platoon sergeant in 1981-1984 at Fort Hood and had the unfortunate fate of being signed for 12 of these devils. At the bottom of page 39 of t he book are what looks like some of my former charges ?racked and stacked ? on the Santa Fe for a trip to Beaumont, Texas and REFORGER 84. Two of t hem appear to be AN/TRQ-37 shelters with a towed PU-620 twin 5 kWt generato r set behind them, and one looks to be an AN/TRQ-32. These were signal inte lligence systems but often were more reliable than the truck that carried t hem.
Overall this is a good book for basic modeling of the ?Goat, but as note d if you want to use it for other than the listed units, you will have to f ind a shelter or scratchbuild one.
Cookie Sewell