The engineering feat that revolutionized the landing process

The American “duck”

The DUKW is an amphibious modification of the General Motors Company (GMC) AFKWX military truck used in World War II. This model was a specialized version of GMC’s CCKW six-wheel-drive military truck with a cab-over-engine design and a longer cargo bed. AFKWX stood for “A” - 1939 design, “F” - Forward cab, “K” - All wheel drive, “W” - Tandem rear wheels, “X” - Extended bed. Via the modifications, American troops were able to transport goods (a payload of 2.5 tons) or around 20 troops with all their equipment, on land and as well on water. This engineering feat revolutionized the landing process since, so far, the supply ships had to dock before unloading their cargo in ports which was a time-consuming operation. The DUKW proved remarkably reliable and versatile in all situations. Beside their normal duties, some were used as naval ambulances, while some provided fire support, just to mention some special purposes they were used for. They are still in use today either for military or police training or in civilian use, mostly in tourism on “duck tours”.

The vehicle was designed by yacht designers Sparkman & Stephens in collaboration with General Motors involving Dennis Puleston, a British designer and environmentalist, and Frank W. Speir from the Massachusetts Institute of Technology. Developed in only 38 days, the initial design was rejected by the military. The Army changed its mind when a Coast Guard patrol craft ran aground on a sand bar near Provincetown, Massachusetts in a storm, and a DUKW prototype happened to be in the area for a demonstration and saved the crew of the patrol craft. This achievement gave green light to the project.

Approximately 21,147 were manufactured between 1942-1945. A quarter of all DUKWs held a .50-caliber Browning heavy machine gun in a ring mount. The name DUKW comes from the model-naming terminology used by GMC: “D” for designed in 1942, “U” for utility, “K” for all-wheel drive, and “W” for two rear axles. It was nicknamed “Duck” by the soldiers. The DUKW featured a Chevrolet engine with 104 horsepower. The vehicle was able to reach 50 mph or 80 km/h on ground and 5.5 knots (6 mph or 10km/h) on water. Its empty weight was 6.5 tons and it could carry a 2.5-ton payload. It measured 31 feet in length, 8 feet in width and 7 feet in height.

The 6x6 all-wheel drive DUKW was the first vehicle to allow the driver to vary the tire pressure from the driver’s compartment with the help of the so-called Speir's device named after the engineer involved in the development of the vehicle. This central tire inflation system improved performance on different surfaces. The fully inflated tires were good for hard surfaces such as roads and less inflated tires gave better grip on softer ground like beach sand.

The main recipients of the DUKWs were the U.S. Army and Allied forces, with 2,000 provided in the Lend-Lease program to Britain. The rest were acquired by Australian forces and the Soviet Union. The Soviets even made their own version, the BAV 485, which was produced until 1962.

These vehicles were initially used in Guadalcanal in March 1943, then, for the first time in a landing role, in the invasion of Sicily in Operation Husky, and later on the beaches of Normandy on D-Day and in other operations in Europe on the road to the heart of the Third Reich. On D-Day at Omaha Beach, it suffered heavy losses to due its improper use. The DUKW was supposed to be used in good weather, where it could perform its tasks very well. On the contrary, in bad weather and surrounded by high waves, it was not seaworthy, especially if it was fully loaded with cargo. On Omaha Beach, they were completely overloaded since, on top of the supplies, they were equipped with heavy weaponry, such as howitzers. With the exception of one such DUKW, all of the vehicles carrying howitzers sank shortly after debarking from their carriers. From our earlier newsletter regarding the assault on the promontory of Pointe du Hoc, you may also remember that in the daring operation U.S. Rangers used specially modified DUKWs with 100foot/30m extension ladders to climb the steep cliffs of the Norman coast and to take the German positions there.

General and later President, Dwight Eisenhower wrote that, according to most senior officers, the bulldozer, the Jeep, the 2,5-ton truck, and the C-47 airplane were the four most vital pieces of equipment to the Allies’ success. He regarded the DUKW as “one of the most valuable pieces of equipment produced by the United States during the war.”

Apart from the unfortunate example of Omaha Beach, the vehicle was an outstanding success in its primary role: the ship-to-shore-and-beyond shuttling of personnel and war materiel. After World War II, only reduced numbers were kept in service by the United States, with hundreds sent to the Korean War and Vietnam. Some DUKWs were decommissioned and distributed to the police or to civilian search-and-rescue units. You can also buy some of the remaining versions in good condition in auctions for a price ranging between $20,000 - 65,000 or even more. Original DUKWs and replicas also became famous as tourist attractions in many spots of the world, although its success in tourism was sometimes overshadowed by deadly accidents which occurred due to its improper use in rough waters in bad weather.