Hugh Iorys Hughes (16 April 1902 – 16 August 1977) was a Welsh civil engineer and keen yachtsman who submitted ideas to the War Office for the design of the Mulberry harbours used in Operation Overlord. Hughes was born in Bangor, where he attended Friars' School, and grew up in the Conwy area, becoming familiar with its waters. He studied engineering at the University of Sheffield. Afterwards he went to work for Owen Williams, a designer of concrete structures, specialising in bridges. On the outbreak of war, he was unable to join the armed services because he was now in a reserved occupation. In 1917 Churchill drafted plans for the capture of the islands of Borkum and Sylt, off the Dutch and Danish coasts. He planned to use sunken caissons filled with sand to form an artificial breakwater on the seabed. The proposal was shelved and forgotten. In 1940 the civil engineer Guy Maunsell wrote to the War Office with a proposal for an artificial harbour, but the idea was not adopted. In 1942 Hughes came up with a similar idea for using caissons as part of a jetty while working as a civil engineer in London. He also submitted his plans to the War Office, and these were ignored until Hughes' brother, Alain Sior Hughes, who was a Commander in the Royal Naval Volunteer Reserve, drew attention to the documents. Following Winston Churchill's memo Piers For Use On Beaches, dated 30 May 1942, the Mulberry project gained momentum under the direction of Major General D J McMullen and civil engineer Brigadier Bruce White. An early priority was the construction of trial installations in the Clyde estuary at Gare Loch. Hughes designed and supervised construction of a prototype jetty consisting of 'Hippo' concrete caissons sunk on the sea bed supporting 'Crocodile' steel roadway bridge units which spanned between the Hippos. The prototype was built at Conwy Morfa near Hughes' home town of Conwy and towed to Garlieston, Wigtownshire, in Scotland, where it was installed and tested against two other designs, both of which were floating roadways; the "Swiss Roll", designed by R M Hamilton, was made of canvas and steel cables, while the "Whale" roadway designed by Allan Beckett consisted of flexible bridge spans mounted on pontoons. During the testing a storm washed away the Swiss Roll and created scour of the sea bed around the Hippo units, which in