Welsh civil engineer Hugh Iorys Hughes — expert sailor with a lifelong interest in boat design — was one of the several leading UK engineers who worked on the top-secret Mulberry Harbour project in World War II in preparation for the allied D-Day landings on the French coast (Operation Overlord). A shy man who never talked about his achievements, Hughes deserves wider recognition for his war work and for his significant concrete structures on land that we still use today.

Hughes grew up on the north Wales coast near Conwy, where he spent a lot of time sailing — a pursuit he would continue all his life. He was educated locally, followed by engineering studies at the University of Sheffield. On graduation, he joined the consultancy of innovative structural concrete designer Owen Williams (1890-1969), where he spent the first 15 years of his career, acting as senior resident engineer on a series of notable concrete buildings and bridges.

When the Second World War broke out in 1939, Hughes tried to join the Royal Navy but was refused, as engineering was a reserved occupation. Following the Dunkirk evacuation of 1940, the importance of controlling a port to supply the army was clear, if an invasion of occupied Europe was to succeed. In December 1940, Guy Anson Maunsell (1884-1961) proposed towing precast hollow concrete units across the Channel and linking them together to form harbours or jetties. Early in 1941, Hughes envisaged concrete caissons and roadway units to perform a similar function.

Both ideas were put to the War Office but went no further, until Hughes' brother Sior (1910-82), a Royal Naval Volunteer Reserve commander, brought Hughes' plan to the attention of senior officers. In June 1942, Hughes was asked for proposals. His design was among three selected for evaluation. All had to carry heavy tanks and artillery, withstand summer gales and be moveable from one beach to another.

In October 1942, construction of three prototype concrete caissons with steel towers (code named 'Hippo') and two steel bridging road units (code named 'Croc') commenced at the Conwy Morfa sand spit. Astonishingly, even with around 1,000 men on site, supervised by Hughes and engineer Oleg Aleksandrovich Kerensky (1905-84), the work remained secret. By May 1943, the gigantic prototypes were ready to move and they were towed to Scotland for full-scale trials.

The plan for the Mulberry Harbours was now coming together, using elements developed separately around the country. Hughes' Hippo design was modified to form the Phoenix caissons to be used as breakwaters, developed by Oscar Faber (1886-1956). Hughes' commitment was such that Prime Minister Winston Churchill (1874-1965) invited him to act as a consultant. He was offered the (temporary) rank of Colonel but refused. The extraordinary task of constructing enough elements to build two harbours for the D-Day Landings now commenced.

Hughes lived and worked at Selsey Bill, West Sussex, and at Dungeness, Kent — the principal coastal sites where completed caissons were parked before dispatch. Disguised as a French fisherman, he made several visits to Normandy to take soundings and record tidal movements. He also developed methods for towing, sinking and anchoring the caissons, and he helped with installation of the breakwaters in June 1944. His role in translating the ideas behind Mulberry into practical form was disclosed to Parliament on 21st December 1944.

In peacetime, he returned to his London office and large-scale reinforced concrete construction. He also returned to ocean racing. In 1946, he skippered the yawl Lafita across the Atlantic to compete in the Bermuda Race (Newport, Rhode Island to Bermuda), coming fifth. While in Bermuda, he won a race against local sailors, before completing a record passage home from Bermuda to Cowes, Isle of Wight. On his return, he married Jane Vernon.

Hughes died in 1977, aged 75. One obituary describes him as "a delightful companion, having a likeable sense of humour, coupled with a modesty so unassuming that only his close friends appreciated his outstanding qualities". His ashes were scattered on the Menai Strait.

1902	Born 16th April in Bangor, Wales, fourth child of Owen Rowland Hughes (1864-1952, draper) and Mary Catherine Hughes (b. 1869, same surname, no relation), with siblings — Violet Helen Mary (b.1895), Leslie William Alfred (1898-1960), Guinever [Guenever] (b.1899), Richard Alwyn (1906-73) and (Alain) Sior (1910-82)
1913-19	Attends Friars School in Bangor, described as "highly-strung", with "sandy curls and a slight stammer, which he disguised by talking slowly"
1919-c.23	Attends Sheffield University, first class honours degree in engineering despite almost withdrawing from finals through nerves
c.1923-38	Senior resident engineer for Owen Williams (1890-1969) on bridges and other large concrete works in Scotland and in London
1924	Becomes (18th November) student attached to Institution of Civil Engineers (ICE)
1930	Elected (10th December) associate member of ICE
1938-40	Working as consulting engineer from offices at 66 Victoria Street SW1, London, living at 30 Pembridge Gardens, Kensington
1941-44	Working on the Mulberry Harbours, draws up proposals (dated 17th June to 6th August 1942), constructs three Hippos and two Crocs on Morfa Conwy, first Hippo launched 4th May 1943, followed by rigorous testing at Rigg Bay, Scotland, consultant on construction, deployment and installation of Phoenix caissons for Mulberry Harbour breakwaters
c.1945	War Office payment for Mulberry Harbour work delayed and fee reduced fee, he agrees (not wanting to appear as a war profiteer), costs barely covered, ends the war in a worse financial position than when he started
1946	Marries Jane Vernon on return from Newport to Bermuda sailing race, in which his yawl Lafita was placed fifth, also sails 2,850 nautical miles (5,278km) between Madeira and New York
1954	Founder member of the Ocean Cruising Club — members must have completed a non-stop ocean passage between two ports at least 1,000 nautical miles (1,852km) apart, also later a member of Royal Thames Yacht Club, West Mersea Yacht Club, Conwy Yacht Club and Royal Ocean Racing Club
1958-62	Designs and supervises construction of underpasses and subways at London's Hyde Park Corner, part of the Park Lane Improvement Scheme
1958-67	Designs and supervises construction of Blackwall Road Tunnel southbound (road tunnel), London
1960	Suffers a heart attack but makes a full recovery
1967	Compiles a series of notes (27th February) on his role in Mulberry Harbour project
1968	Retires to Besom House, 94 Coast Road, West Mersea, Essex
1977	Dies (16th August), survived by his wife, ashes scattered on Menai Strait
1978	Commemorative stone unveiled (6th June) at Morfa Conwy to mark the site of Hippo and Croc construction, exhibition held at Conwy's Guildhall

Wembley Stadium (original) (resident engineer), Wembley, London, UK .... c.1923-24
Findhorn Bridge (resident engineer), Tomatin, Highland, Scotland, UK .... 1924-26
Montrose Bridge (resident engineer), Montrose, Angus, Scotland, UK .... 1927-30
Empire Pool (now Wembley Arena) (resident engineer), Wembley, London, UK .... 1933-34
Mulberry Harbour prototypes (design and construction), Morfa Conwy, Wales, UK .... 1941-43
Mulberry Harbour prototypes (testing), Rigg Bay, Garlieston, Scotland, UK .... 1943
Mulberry Harbours (implementation), southeast England, UK, and Normandy, France .... 1943-44
Cutty Sark dry dock, Greenwich, London, UK .... 1954
Park Lane Improvement Scheme (Hyde Park Corner underpasses and subways), London, UK .... 1958-62
Blackwall Road Tunnel southbound (approaches), Poplar to Greenwich, London, UK .... 1958-67

K.J. Thomas, H. Iorys Hughes, Panel for Historical Engineering Works Newsletter, ICE Wales Cymru, 12th September 2009

Biographical information: Hugh Iorys Hughes, Iorys Hughes collection, Institution of Civil Engineers, London, c.1978

Obituary: Hugh Iorys Hughes, bound volumes of obituaries collection, Institution of Civil Engineers, London, 26th January 1978

Prof. Sir Alan Harris, The Mulberry Harbours, Transactions of the Newcomen Society, London, 9th May 1990

Max Hastings, That Fatal Shore, Bonhams Magazine, Issue 39, p.3, Summer 2014

Mark Hughes, Conwy Mulberry Harbour, Gwasg Carreg Gwalch, Llanrwst, Wales, 2001

Cliff Jones, If at first you don’t succeed, The Old Dominicans’ Association Newsletter, Friars School, Summer 2010

K.J. Thomas, Draft letter to New Civil Engineer about H. Iorys Hughes, (unpublished) May 2009

Nigel Watson and Frank Turner, Maunsell: the Firm and its Founder, AECOM Technology Corporation, Hong Kong, 2005

Progress of the Park Lane Improvement Scheme, The Engineer, London, pp.698-699, 28th October 1960

The changing traffic pattern in Central London &endash; the Hyde Park Corner &endash; Marble Arch improvement scheme and the Park Lane underground garage, Concrete Quarterly, London, Number 56, pp.6-11, January-March 1963

With grateful thanks to Tony Millatt, Mersea Museum, and Medwyn Parry, RCAHMW, for additional information.

http://discovery.nationalarchives.gov.uk

www.combinedops.com

www.ddaymuseum.co.uk

www.historicengland.org.uk

www.oceancruisingclub.org

www.secretscotland.org.uk

www.westmersea.org