Search our Website

Building the Mulberry Harbors in England - WWII

Previous | Index | Next »

Labor Shortages, & Other Problems in Building the Mulberry Harbors

Mulberry harbor construction
Construction work on Mulberry harbors in Britain. Harbor components would be towed by tug across the English Channel to the Normandy coast -  WWII.

Once the Allies agreed upon building two prefabricated harbors, many problems ranging from design issues to transportation had to be solved. Labor shortages in England produced complications which needed to be addressed in order to build the components for the two Mulberry harbors.

Problematic as well, was the fact that special skills were needed for some of the work or training must be done. Some of the work needed to take place at a considerable height and much work would need to done outside, regardless of the weather. Accommodations would need to be available for the workers, and meals and transportation to and from work arranged. There was a shortage of materials such as steel, and in some instances it was necessary to substitute concrete for building some of the components.

With enormous expenditure of energies, these problems were all addressed and the construction phase was seen through to completion, with the help of thousands of workers from all over Great Britain. Another problem that was addressed was a shortage of tugs which would be needed to tow the Mulberry components across the English Channel. Royal Navy photo above shows British construction site for Mulberry harbor.

Towing and placing the Mulberry Harbor Components

Phoenixes  and a spud pier, Mulberry harbor components, waiting to be placed on coast of Normandy.
Two Phoenixes (top and bottom) and a spud pier (center), Mulberry harbor components, waiting to be placed on coast of Normandy. WWII.

In advance of the fleet, mine sweepers began to sweep the channel and several types of beach obstacles were removed. The 400 separate components of the two harbors were brought together to be towed across the English Channel beginning on June 6th 1941. The total weight of these structures was million and a half tons, and no fewer than 10,000 men were involved in the towing and positioning; 160 tugs, were found for towing, but this was not enough to do the job in one crossing, making return trips necessary.1 All components in transit would be under the protection of escort ships. U.S. Navy photograph above shows Phoenix caisson units (top and bottom) and spud pier (center) waiting to be placed for Mulberry Harbor. Note tugboat to the left.

After towing the components across the English Channel, work began on placing the breakwater and constructing the harbors on June 7, 1944 (D + 1) in expectation of operational harbors by June 20 (D + 14). Any loss of structures in transit, meant a redesign of the harbor as its assembly was in progress. The American Mulberry A was constructed on Omaha Beach with a planned capacity of 5,000 tons per day. The British Mulberry B was constructed at Arromanches on Gold Beach with a planned capacity of 7,000 tons per day. The Calvados reef gave some additional protection to Mulberry B.


Expectations were that the Mulberry harbors would enable a steady stream of troops, vehicles, and supplies to be delivered. Roadways would connect the piers to the shore.

Craft such as LSTs, coasters, and small cargo ships could unload at the spud piers, and return immediately for more goods, regardless of the tide. The calm water would also allow DUKWs, Rhino barges (ferries), small ships and other barges to deliver cargo directly to shore.


1Yves Buffetaut, D-Day Ships – the Allied Invasion Fleet, London: Conway Maritime Press, 1994, p.131.