DUKW

The DUKW — universally the "Duck" — is a six-wheel-drive amphibious truck built by GMC from 1942. Around 21,000 were produced, making it the most numerous amphibious vehicle in history.

The designation is not an acronym in the usual sense but GMC model code: D for 1942 design year, U for utility amphibious, K for front-wheel drive, W for tandem rear axles.

Design

A boat hull was wrapped around the chassis and running gear of the GMC CCKW 2½-ton truck. A single propeller at the stern drives it in water, with steering by rudder assisted by the front wheels. The DUKW was the first vehicle to carry a driver-operated central tyre inflation system, letting the crew drop pressure for soft sand and raise it again for road work — an innovation that long outlived the vehicle itself.

Service

Its purpose was the stretch no other vehicle could cover: carrying cargo from ship to shore and then inland without transferring loads at the waterline. It served at Sicily, Normandy, and across the Pacific. Post-war it found a long second life with tour operators, a role in which some examples still work today, and one that has drawn sustained scrutiny over passenger safety.