The Ministry of Information presents this World War II documentary, produced by The Admiralty and The Army Film Unit. The black-and-white film covers the process of constructing, transporting, and installing the artificial harbors, Mulberry A and B, only a few days after D-day and the invasion of the beaches of Normandy. The British Army designed and built the harbor in the UK and transported them by sea to France to solve the problem of transporting supplies and vehicles to France along the Normandy coastline, where already existing harbors were too scarce.