Ford GPA "Sea Jeep"

The Ford GPA 'Seep' (Government 'P' Amphibious, where 'P' stood for its 80-inch wheelbase) was an amphibious version of the World War II Ford GPW jeep. Unlike the jeep, the seep was not a successful design; it was considered too slow and heavy on land, and lacked sufficient seagoing abilities in open water. The design features of the much larger and more successful DUKW amphibious truck were used on the GPA.

After having commissioned Willys, Ford and Bantam to build the first 4,500 jeeps (1500 each) in March 1941, the US Motor Transport Board set up a project under the direction of the National Defense Research Committee (NDRC) to be designated "QMC-4 1/4 Ton Truck Light Amphibian".

Roderick Stephens Jr. of Sparkman & Stephens Inc. yacht designers was asked to design a shape for a 2,700-pound amphibious jeep, in the same vein as his design for the DUKW six-wheel-drive amphibious truck. Stephens' hull design looked like a miniature version of that of the DUKW, and just like it, the 'Seep' was going to have a screw propeller, driven by a power take-off, operating in a dedicated tunnel faired into the rear end bodywork, as well as a proper rudder. The GPA's design was based on the Willys MB and Ford GPW standard Jeeps as much as possible, using many of the same parts. The GPA had an interior similar to that of the MB/GPW jeeps, although the driver's compartment had almost twice as many control levers: 2WD/4WD, hi-range/lo-range, capstan winch (on the bows), propeller deployment and rudder control.

In contrast to the DUKW, the GPA did not perform well in the field. At some 3,500 lb the production truck had become much heavier than the original 2,600 lb specified in the design brief, but its volume had not been increased accordingly. As a consequence, a low freeboard in the water meant that the GPA could not handle more than a light chop or carry much cargo. The GPA's intended use of ferrying troops and cargo from ships off-shore, over a beach and continuing inland, was therefore very limited.

On land, the vehicle was too heavy and its body too unwieldy to be popular with the soldiers. GPAs would frequently get stuck in shallow waters, where the regular Willys MB's water fording abilities allowed it to drive straight through[3][page needed]. Production was already halted in March 1943 after production of only 12,778 vehicles[1] due to financial quibbles between Ford and the US government, as well as bad reception of the vehicle in theatre. Although some sources state that less than half of that number were ever completed [4][page needed], serial numbers of surviving specimens suggest that the figure of around 12,700 is actually correct.[5]

In spite of participating in the Sicily landings of September 1943, most GPAs were routed to the Soviet Union under the Lend-Lease programme. A small number of GPAs were used in action in North Africa and the Pacific.

The USSR developed a derivative of the GPA after the war. The GAZ-46 MAV, which closely resembled the GPA, entered production in 1952. The GAZ-46 was exported to many[citation needed] USSR-allied countries.

GPAs were also sold as surplus and were purchased by farmers, ranchers, adventurers and others. By the 1970s, collectors had discovered them, and started restoring them back to their original specifications. They appear at various military vehicle shows.