When the British Army were planning D-Day they needed some where for the boats to dock.  So they invented a harbour called Mulberry.  So people back home set to work building this big harbour.  It was top secret.  Each Mulberry harbour consisted of roughly 10 kilometres of flexible steel roadways (code-named Whales) that floated on steel or concrete pontoons (called Beetles). They built concrete caissons in sections (code name phoenix). Then after they had finished a caisson they got it ready to tow across the channel to Normandy with tug boats. The harbours arrived 12 days after D-Day.  The sections were made out of reinforced concrete. Some people think that concrete can’t float.  But these sections were made very carefully with valves so they were watertight when towed.  When the caissons were in place the wheels were turned and water flooded in, then each bit sank. They were protected by a line of sunken old ships that made a breakwater (code name Gooseberries). The roadways terminated at great pierheads, (code name Spuds) they were jacked up and down on legs which rested on the seafloor.

 

 The Allies needed this so that the big ships could unload cars, weapons, tanks, food and other supplies for the troops.

 

One harbour “A” was at Omaha beach the other “B” was at Gold.  Gold beach was a place called Arromanches.  The first night there was a storm and everything was delayed.  Then when the mulberrys were built there was a terrible storm and the Mulberry at Omaha was completely destroyed. The Americans had to do things the old way: bringing landing ships into shore, grounding them, off-loading the ships, and then refloating them on the next high tide.

The one at Gold beach was damaged but still useable. This was the only way that supplies were brought to the troops in France after D-Day. It supported the Allied armies for 10 months. Two and a half million men, a half-million vehicles, and 4 million tons of supplies landed in Europe through the Mulberry at Arromanches.