DUKW Information

The DUKW (colloquially known as Duck) is a six-wheel-drive amphibious modification of the ​2 1⁄2-ton CCKW trucks used by the U.S. military during World War II and the Korean War.

Designed by a partnership under military auspices of Sparkman and Stephens and General Motors Corporation (GMC), the DUKW was used for the transportation of goods and troops over land and water. Excelling at approaching and crossing beaches in amphibious warfare attacks, it was intended only to last long enough to meet the demands of combat. Surviving DUKWs have since found popularity as tourist craft in marine environments.

The name DUKW comes from General Motors Corporation model nomenclature:

Decades later, the designation was explained erroneously by writers such as Donald Clarke, who wrote in 1978 that it was an initialism for "Duplex Universal Karrier, Wheeled".

The DUKW was designed by Rod Stephens, Jr. of Sparkman and Stephens, Inc. yacht designers, Dennis Puleston, a British deep-water sailor resident in the U.S., and Frank W. Speir from the Massachusetts Institute of Technology. Developed by the National Defense Research Committee and the Office of Scientific Research and Development to solve the problem of resupply to units which had just performed an amphibious landing, it was initially rejected by the armed services. When a United States Coast Guard patrol craft ran aground on a sand bar near Provincetown, Massachusetts, an experimental DUKW happened to be in the area for a demonstration. Winds up to 60 knots (110 km/h; 69 mph), rain, and heavy surf prevented conventional craft from rescuing the seven stranded Coast Guardsmen, but the DUKW had no trouble, and military opposition to the DUKW melted. The DUKW later proved its seaworthiness by crossing the English Channel.

The final production design was perfected by a few engineers at Yellow Truck and Coach in Pontiac, Michigan. The vehicle was built by Yellow Truck and Coach Co. (GMC Truck and Coach Div. after 1943) at their Pontiac West Assembly Plant and Chevrolet Div. of General Motors Corp. at their St. Louis Truck Assembly Plant; 21,147 were manufactured before production ended in 1945.

The DUKW was built around the GMC AFKWX, a cab-over-engine (COE) version of the GMC CCKW six-wheel-drive military truck, with the addition of a watertight hull and a propeller. It was powered by a 269.5 cu in (4 l) GMC Model 270 straight-six engine. A five-speed overdrive transmission drove a transfer case for the propeller, then a two-speed transfer case to drive the axles. The propeller and front axle were selectable from their transfer case. A power take-off on the transmission drove an air-compressor and winch. It weighed 13,000 lb (5,900 kg) empty and operated at 50 miles per hour (80 km/h) on road and 5.5 knots (6.3 mph; 10.2 km/h) on water. It was 31 feet (9.45 m) long, 8 feet 3 inches (2.51 m) wide, 7 feet 2 inches (2.18 m) high with the folding-canvas top down and 8 feet 9 inches (2.67 m) high with the top up.

It was not an armored vehicle, being plated with sheet steel between 1⁄16 and 1⁄8 inch (1.6 and 3.2 mm) thick to minimize weight. A high-capacity bilge pump system kept it afloat if the thin hull was breached by holes up to 2 inches (51 mm) in diameter. One in four DUKWs mounted a .50-caliber Browning heavy machine gun on a ring mount.

The DUKW was the first vehicle to allow the driver to vary the tire pressure from inside the cab. The tires could be fully inflated for hard surfaces such as roads and less inflated for softer surfaces, especially beach sand. This added to its versatility as an amphibious vehicle. This feature is now standard on many military vehicles.

The DUKW was supplied to the U.S. Army, U.S. Marine Corps and Allied forces, and 2,000 were supplied to Britain under the Lend-Lease program; 535 were acquired by Australian forces, and 586 were supplied to the Soviet Union, which built its own version, the BAV 485, after the war. DUKWs were initially sent to Guadalcanal in the Pacific Theater, but were used by an invasion force for the first time in the European theater, during the Sicilian invasion, Operation Husky, in the Mediterranean.

They were used on the D-Day beaches of Normandy and in the Battle of the Scheldt, Operation Veritable, and Operation Plunder.

In the Pacific, USMC DUKWs were used to cross the coral reefs of islands such as Saipan and Guam and the tires were not affected by the coral.

Some DUKWs used in WW2 were reported to have capsized while landing at Omaha beach during the Normandy invasion.

After World War II, reduced numbers were kept in service by the United States, Britain, France, and Australia, with many stored pending disposal. Australia transferred many to Citizens Military Force units.

The U.S. Army reactivated and deployed several hundred at the outbreak of the Korean War with the 1st Transportation Replacement Training Group providing crew training. DUKWs were used extensively to bring supplies ashore during the Battle of Pusan Perimeter and in the amphibious landings at Incheon.

Ex-U.S. Army DUKWs were transferred to the French military after World War II and were used by the Troupes de marine and naval commandos. Many were used for general utility duties in overseas territories. France deployed DUKWs to French Indochina during the First Indochina War. Some French DUKWs were given new hulls in the 1970s, with the last being retired in 1982.

Britain deployed DUKWs to Malaya during the Malayan Emergency of 1948–60. Many were redeployed to Borneo during the Indonesia–Malaysia confrontation of 1962–66.

The Royal Marines used five of these vehicles for training at 11 (Amphibious Trials and Training) Squadron, 1 Assault Group Royal Marines at Instow, North Devon. Four were manufactured between 1943 and 1945. The fifth is a DUKW hull copy manufactured in 1993 with unused World War II-vintage running gear parts. In 1999, a refurbishment programme began to extend their service life to 2014. DUKWs were removed from service in 2012.

The DUKWs were used for safety, allowing all ranks to undertake training drills for boat work for the landing craft ranks, and drivers undertaking wading drills from the Landing Craft Utility.

In the latter 1940s and throughout the 1950s, while Speir, now project engineer for the Armys Amphibious Warfare Program, worked on "bigger and better" amphibious vehicles such as the "Super Duck", the "Drake", and the mammoth BARC (Barge, Amphibious, Resupply, Cargo), many DUKWs were made surplus and used as rescue vehicles by fire departments and Coast Guard stations.

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