WW2: The Floating M4 Sherman Tank

DD tanks (the DD standing for Duplex Drive, but nicknamed Donald Duck tanks[1]), were a type of amphibious swimming tank developed by the British during the Second World War. The phrase is mostly used for the Duplex Drive variant of the M4 Sherman medium tank, that was used by the Western Allies during and after the Normandy Landings in June 1944. DD tanks worked by erecting a 'flotation screen' around the tank, which enabled it to float, and had a propeller powered by the tank's engine to drive them in the water. The DD tanks were one of the many specialised assault vehicles, collectively known as Hobart's Funnies, devised to support the planned invasion of Europe.