The DUKW also known as the DUCK is a well known and much respected vehicle from the Second World War. This brilliant machine was developed by the United States of America, for the transportation of Ammunition, Supplies, Troops, and Equipment from supply ships offshore to fighting unit's on the beach and to supply dumps. If the unloading point was more than 4 mile's inland then area's were established where there cargoes would be transferred to trucks for longer journey's inland. Up to 21,000 Dukw's were produced during WWII at an approximate cost of $10,750.00 dollars and 2,000 of these through the lend-lease scheme were provided to the British.
The parent vehicle for the Dukw was the GMC CCKW 353 2½ ton 6x6 army truck which had been in production for about 18 month's. Its engine a GMC Straight-6 270 cubic inches (4.4L) had been around for ten years and was being used in over five hundred thousand truck's and buses.
The Dukw played a big part in the D-Day landings, on D-Day over Two Thousand dukws were deployed landing many troops in Normandy, over the course of ninety days the dukw's carried 3,040,000 tons of supplies ashore.
A British RASC company consisted of four hundred and seventy men and one hundred and thirty two Dukw's, the ideal strength was four men per Dukw.
A U.S. Dukw company consisted of one hundred and seventy three men and seven officers with fifty Dukw's.
To change the truck into the amphibious DUKW the power plant, transmission, transfer case, drive shafts, axles, and brake system could be used without much change, but the cab and body parts, winch, cooling system, cab, and steering gear would have to be removed and fitted into a special hull.
The shape of the bow and stern were determined by the angles of approach and departure. The hull sides were rounded at the bow for lower water resistance and better visibility. The hull was constructed of welded sheet steel, to save money the drivers compartment was made of plywood.
In the early stages of developing the Dukw it was realised that large quantities of water would be shipped during normal operations, and a highly efficient bilge pumping system would be required. As the Dukw would spend a lot of time ashore normal bilge pumps would be useless. Three bilge pumps were selected, a hand pump for when the propshaft is not turning, a self priming manifold pump, and a high capacity pump which starts automatically when the water level in the centre bilge gets deep enough to prime the pump. The final bilge system had a total capacity of approximately 300 gallons per minute.
The cooling system of the Dukw is unusual in that air is drawn from behind the driver, pushed through the radiator and exhausted on each side of the driver. Approximately 40 to 50 different combinations of radiators, fans, shrouds and ducts were tried during the development of this system. The heating system is quite elaborate due to the danger of water freezing on the deck or in the bilges or even the bilge pumps. The exhaust air from the engine blows into the forward compartment and out through ducts at the cabside, by the use of shutters on these outlets the air can be circulated to the hull sides, side decks, cargo compartment, stern, and below the floor to warm the bilge.
Dukw's were mostly built by women, they were mainly used to transport supplies, soldier's and weapon's from ships to land where there were no harbours for boat's to dock.
Dukw's were used in Okinawa, Iwo Jimo, Sicily, Salerno, Napels, New Guinea, the Philipines, Manilla, and for crossing the Rhine in 1945.