In 1941 the Jeep entered production with Willys, Ford and Bantam, next the US Motor Transport Board set up a project designated ‘QMC-4 1/4 Ton Truck Light Amphibian’. As the war progressed bridges over Europe's rivers were being taken out one after another by the retreating Germans. An ideal solution was to create a jeep that could swim as well as drive.
Following on from the DUKW amphibious truck Roderick Stephens Jr. of Sparkman & Stephens Inc. yacht designers, designed the shape for a 1200kg (2700lbs) amphibious jeep. Not surprisingly Stephens' hull design looked like a miniature version of that of the DUKW. The design maintained many of the DUKW features such as a screw propeller and a rudder.
The construction of the vehicle was developed in competition by Marmon-Herrington and the Ford Motor Company. After a direct comparison of the two company's prototypes, Ford received a contract for production starting in 1942.
In contrast to the DUKW the GPA (G=Government, P=80" wheelbase, A=Amphibious) did not perform well in the field. It weighed 400kg more that the initial design specifications called for, but its volume hadn't been increased accordingly. As a consequence it sat too low in the water and couldn't handle more than a light chop, and certainly couldn't take much cargo.
The GPA's intended objective: to ferry soldiers to and from ships off-shore and to continue up the beach and inland was not met. When used this way many GPA Jeeps sank if there were any significant waves at all.
It proved to be too slow, heavy and clumsy on land and too small to be a good boat in open water. Production was halted in March 1943 after 12,778 vehicles for financial reasons and negative feedback from the front.
The GPA did see important use with the US for the Sicily Landing on 9 September 1943, but most of the vehicles ended up being passed to the Soviet Union under the Lend-Lease Scheme. Ironically, its river crossing capabilities were found to be so useful by the Soviets that the design was developed further in producing their own post-war version.
Starting out with the chassis of the GAZ-67B, prototypes were created that largely copied the GPA’s layout and design, eventually leading to the GAZ 46 MAV, based on the chassis and mechanicals of the GAZ 69 4x4 jeep, to go into production as of 1952.
Eastern Europe is criss-crossed with rivers and the GPA made an ideal transport option for the advancing Soviet armies to cross them.
In Flames Of War
Instead of equipping your Transporter Platoon (Page 16, Hammer and Sickle) with trucks you can choose to upgrade them to Ford GPA Amphibious Jeeps for +5 points for the platoon.
Amphibious vehicles are designed to swim, carrying their passengers across rivers or lakes.
Amphibious vehicles treat all Impassable water terrain as Difficult Going instead of Impassable. If passengers are forced to Dismount for any reason while in Impassable water, they drown and count as Destroyed.