Mulberry Harbour, Arromanches: General view of the main portion of Mulberry "B" at Arromanches as it begins to operate as a port.
The Allies could not rely on capturing an undamaged port, so two artificial harbours were planned, one in the British sector and one in the American. Each was assembled from 400 prefabricated sections. The American harbour was badly damaged in a storm, and only the British one was ever used.