While planning the invasion of Normandy (Operation Overlord), the Allied Command considered it absolutely necessary to have deep-water ports in order to dispatch reinforcements to the continent. However, the Canadian assault against Dieppe on 19 August 1942 had shown how thoroughly the German command had fortified these ports. They could not be captured without significant loss of lives and in the process, the port facilities would be reduced to ruins.

The solution found by the Allied staff was to manufacture the components for two artificial ports in Britain, to be towed across the Channel and assembled on site. One of them was planned off the American landing zone called Omaha Beach, (Vierville-sur-Mer), codenamed ‘Mulberry A’, the second (‘Mulberry B’) at Arromanches, off Gold Beach, a British landing zone.

The 50th British Infantry Division that landed there on 6 June, captured Arromanches that same evening. The next day, construction began by sinking old ships to form a breakwater. On 14 June, the first floating road was operational. However, a storm swept through the Channel from 19 to 22 June, damaging the ports.

‘Mulberry A’ turned out to be completely unusable. Some of its surviving elements were used to repair ‘Mulberry B’, which was not as heavily damaged. In total, 529000 tons of supplies came through Arromanches until its closure on 19 November 1944. It was a remarkable feat of technological prowess, but in retrospect, the endeavour proved to be unnecessary and very costly. The Allies managed to land more men, vehicles and goods via a number of small Normandy ports, and even more directly onto the beaches.