WORLD WAR IID-DAY LANDINGS.
THE FIRST KNOWN PLANS DRAWN FOR THE MULBERRY HARBORS.
HUGHES, HUGH IORYS. 9 original pencil drafts, various sizes (19 ½ x 9 ½ inches to 38 x 23 ¼ inches), [London], June 17 to August 6, 1942, being Hughes original designs for the temporary harbors used during the D-Day invasions at Omaha Beach and Arromanches, each additionally annotated by Hughes, each sketch professionally conserved and matted. Drafts include:
1. "General Layout Sketch of Reinforced concrete Jetties To Be Sunk In Place." Signed ("I. Iorys Hughes, M.E."), 1 p, 25 ½ x 11 ¼ inches, June 19, 1942. Includes diagrams of port operation from sea to beach with troop positions, mechanized assault vehicles, tides, bridges and pontoons.
2. "Reinforced Concrete JettiesTypcial Pontoon To Be Sunk In Place." Signed ("I. Iorys Hughes, M.E."), 1 p, 24 ¼ x 17 ½ inches, June 17, 1942. Annotated diagrams of half shear, half longitudinal, half deck, half section and transverse sectional views.
3. "Leader PontoonTo Be Sunk In Place." Signed ("I. Iorys Hughes, M.E."), 1 p, 24 ¾ x 17 inches, June 17, 1942. Annotated diagrams of half shear, half longitudinal, jalf deck, jalf section and transverse sectional views.
4. "Reinforced Concrete Jetties, Details of Steel Bridges." Signed ("I. Iorys Hughes, M.E."), 1 p, 24 ¾ x 13 ¼ inches, June 20, 1942. Annotated diagrams of three types of bridges, and sketch of "Putting Bridges in Place."
5. "Reinforced Concrete Jetties, Lay-Out of Yard." Signed ("I. Iorys Hughes, M.E."), 1 p, 24 ¼ x 10 ¼ inches, June 20, 1942. Annotated diagrams of composite plan and cross section, plus concrete mold composition. Listing estimated costs.
6. "Proposed Landing Jetty, General Details, Slung Span and Cantilever Type." Signed ("I. Iorys Hughes, M.E."), 1 p, 38 x 23 ¼ inches, August 6, 1942. Annotated diagrams of "twistable slung span," decking, concrete frame and hull.
7. "Proposed Landing Jetty, Lay-Out Plan, Slung Span and Cantilever Type." Signed ("I. Iorys Hughes, M.E."), 1 p, 35 ½ x 13 ¾ inches, August 6, 1942.
8. "Proposed Landing Jetty, Notes on Erection, Slung Span Type." 1 p, 19 ½ x 9 ½ inches, n.d. Elevation views of pontoons joined by slung span and cantilever superstructures; composite plan with reference to tidal direction.
9. "Top Plan, Longitudinal Section, and Side Elevation." Signed ("I. Iorys Hughes, M.E."), 1 p, 35 ½ x 19 inches, August 6, 1942. With enlarged view of span in place and midspan section. With detailed construction directions.
HUGH IORYS HUGHES' ORIGINAL WARTIME PLANS FOR THE MULBERRY HARBORS, THE MOBILE PORTS USED DURING ALLIED D-DAY OPERATIONS.
These secret, wartime plans are the prototypes for what would become a key component of the D-Day invasion. Dubbed by historians as one of the greatest military engineering achievements of all time, the "Mulberry Harbours" were the brainchild of Winston Churchill, and the design triumph of Welsh engineer Hugh Iorys Hughes. After the evacuation of Dunkirk in 1940, Allied forces were unable to mount a counter-invasion of the European mainland without access to a port large enough to handle supplies to support the troops. Capturing an existing port like Le Havre would have been difficult, if not impossible. Finding a solution to this problem, Allied leaders knew, would be imperative to defeating the Nazis.
As a member of the War Cabinet during the First World War, Churchill had proposed a mobile port in support of amphibious operations to capture two islands off the coast of Germany. Though shelved at the time, the plan was resurrected during the Second World War by Hugh Iorys Hughes [1902-1977], a Welsh engineer living in London. Hughes had worked on Wembley Stadium and the Hyde Park Corner underpass; he was also an accomplished sailor and diver. In 1941-42, he contacted the War Office to propose construction of a mobile port that could be ferried across the Channel for an invasion of Nazi-occupied Europe. After Hughes's brother, a commander in the Royal Navy, brought the idea to the attention of more senior officers, it caught fire. On May 30, 1942, Churchill, who was already favorably disposed to the idea of a mobile port, sent a famous directive to Admiral Mountbatten, head of Combined Operations: "Piers for use on beaches. They must float up and down with the tide. The anchor problem must be mastered. Let me have the best solution worked out. Don't argue the matter. The difficulties will argue for themselves."
Hughes was chosen to spearhead the project, according to a June 1, 1942 "Top Secret" memorandum. His mandate was to prepare plans for "prototypes of landing piers to be towed across the Channel and sunk into place." The piers were to be "capable of carrying the heaviest tanks and artillery ... [and] of being towed from one assault beach to another...." He would also have to account for projected tidal and wind conditions at the beaches in France.
The present set of plans was drawn up by Hughes during an intensive seven-week period, from June 17 to August 6, 1942. These are his retained copies (one or more others having been delivered to the War Office shortly after their completion). Tasked with validating the plans, Hughes selected the estuary of the River Conwy ("Conwy Morfa") in North Wales as a test site. In late 1942 and early 1943, he recruited almost a thousand workers for the construction and testing of the mobile harbors. The project was so secret that even the men working on it were unaware of its true purpose.
Hughes devised two types of construction, code-named "Hippos" (concrete caissons that could be sunk/anchored in place as pierheads) and "Crocs" (steel roadways elevated over the Hippos, linking them together). These were subsequently towed to another secret test site in Scotland, at Garlieston, Wigtownshire. There, Hughes's efforts were integrated with prototypes developed by two other teams: the Royal Navy Directorate of Miscellaneous Weapons Development (DMWD) and TN5 (Transportation 5), the unit responsible for command of the mobile port project. The work at Garlieston included development and testing of breakwaters needed to make the port and its roadways usable under various tides and weather conditions. Hughes's Hippo plan was ultimately modified into a design code-named "Phoenix"; these caissons would be sunk for breakwater in Normandy on D-Day. After the war, the independent efforts of the teams prior to the Garlieston collaboration would lead to competing claimants to the title of design "creator." Though there is no doubt that the project was a team effort, Hughes's plans appear to be the earliest prototypes for the project.
Code-named "Mulberry Harbours" or "Mulberries," the mobile harbors were completed by May 1944 and successfully launched with the use of tug boats soon after. They were, as Churchill later wrote, "to form a principal part of the great plan." During D-Day operations, Mulberry A was installed at Omaha Beach, for American invasion forces; Mulberry B was set up at Arromanches (Gold Beach) for the British and Canadians. Only two weeks after D-Day, a massive storm destroyed Mulberry A. Mulberry B also sustained some damage, but was reinforced to keep it operable at least until the end of October. As it turned out, Mulberry B was left open until November 19. Hughes was involved throughout, making adjustments and reinforcements to enhance the usefulness of the monumental undertaking.
The Mulberry Harbours made possible the initial landings at Normandy and the continued supply of troops during the Allied invasion that turned the tide of the war. The enemy's perspective on their value is especially revealing. At the Nuremberg Trials, Albert Speer, former Nazi minister of armaments, was forced to admit that the Germans' costly, two-year effort to construct Atlantic defenses had been "brought to nothing because of an idea of simple genius." These plans represent the genesis of that idea.