Mulberry B (for British), also known as Port Winston, was the British floatting port which was built between the 7 June 1944 and the 14 June in front the Norman city of Arromanches-les-Bains. Its construction began on 7 June 1944 with the destruction of around 60 cargo ships and old warship as the Courbet, a French dreadnought which was sunk by its crew under the Marseillaise, or as the Sumatra, a Dutch cruiser. The parts of the dyke were after carried to their places before to be flooded for touch the seafloor, after that, the piers were also carried at their places and flooded for, after, install the wharfs for carry the material from the piers to the beaches.

The principe of the Mulberries ports was to supply the troops after the D-Day without taking one of the very defended ports of the Atlantic Wall which were often destroyed by the occupant when the allied troops were arriving at these.

Between 19 and 21 june 1944, a violent gale happened during the construction of the both Mulberries ports, Mulberry A (for American), located in front of Saint-Laurent-sur-Mer (Omaha Beach) was seriously damaged and abandonned and some of its parts served for repair and upgrade Mulberry B which was very few damaged but which had its construction slowed of three days.

Mulberry B served until 6 months after the D-Day, until the allied troops took the port of Antwerp, Belgium.