Mulberry harbour from the American Ghost Army went to Normandy two weeks after D-Day to simulate a fake Mulberry harbour. The deception was created in such a way that at night its lights drew German gunfire away from the real Mulberries. Mulberry harbour Mulberry harbours were temporary portable harbours developed by the United Kingdom during the Second World War to facilitate the rapid offloading of cargo onto beaches during the Allied invasion of Normandy in June 1944. After the Allies successfully held beachheads following D-Day, two prefabricated harbours were taken in sections across the English Channel from Britain with the invading army
Mulberry harbour Dundas & Whitson, Mowlem, Nuttall, Parkinson, Pauling & Co. and Taylor Woodrow. On completion they were towed across the English Channel by tugs to the Normandy coast at only 4.3 Knots (8 km/h or 5 mph), assembled, operated and maintained by the Corps of Royal Engineers, under the guidance of Reginald D. Gwyther, who was appointed CBE for his efforts. Both locations for the temporary harbours required detailed information concerning geology, hydrography and sea conditions. To collect this data a special team of hydrographers was created in October 1943. The 712th Survey Flotilla, operated from naval base HMS "Tormentor" in