What is less well-known, perhaps, is that Overlord's success depended on engineering of a scale and degree of ingenuity never seen before or since. However, an exhibit recently launched with the help of Dassault Systemes and its CATIA CAD programme is intended to change that by paying tribute to the engineers who helped liberate Europe from Nazism.
The effort takes the form of recreating some of the more innovative aspects of Overlord's engineering efforts. These included the flat-bottomed LCVP landing craft, the wooden Waco glider and the most ambitious of them all: the Mulberry B harbour.
The LCVP and the Waco may seem rather straightforward at first glance. But they are the work of talented engineers who with war raging — under tight constraints and with time and materials in short supply — successfully developed these inventions, which still stand as a source of inspiration for engineers today. Unfortunately, since they were constructed mainly of wood, these craft have all but disappeared, and divers find no traces of LCVPs today. An additional problem lay in how hard it was to read and understand the original plans, most of which were not been well preserved.
This ambitious reconstruction project involved identifying and locating all available sources of information about the three engineering achievements in question. Dassault Systèmes' teams embarked on a lengthy process of and painstaking research, taking them from Normandy to Louisiana, via London, Minnesota and Washington DC.
Behind the project was Dassault Systèmes' Passion for Innovation Institute, which is designed to put the company's technology and knowledge at the service of research, education, culture and artistic creation, helping innovators ask and answer questions about the past and future.
The Institute is dedicated to preserving our world's industrial heritage and in the past has helped solve the mystery of how pyramids were built, recreate the Giza Plateau in Egypt, bring 3D technology to the world of dance and create a historical reconstruction of Paris throughout the ages.
For the LCVP flat-bottomed craft, the plans conserved at the National World War II Museum in New Orleans and the Earl K. Long Library at the University of New Orleans provided a sound basis for the modelling process. This documentation was supplemented by photographs of the landings, particularly those taken by Robert Capa, and by an actual craft painstakingly restored by a team of enthusiasts in Carentan, Normandy.
For the Waco CG-4A glider, one of this type has been reconstructed in Granite Falls, Minnesota, also by a team of amateur enthusiasts, and the microfilms of the original plans were also available for consultation. Dassault's Passion for Innovation Institute produced a 3D laser scan of both the landing craft and the glider.
Isolated remnants of the Mulberry B harbour can still be seen at Arromanches. And the wrecks of the blockships, which formed part of the breakwater around the harbour, still lie on the seabed. But the most revealing clues about how this structure was built and operated came from the original plans, kept at the Royal Engineers' Museum in London, the construction and maintenance manuals, the aerial photographs taken at the time and the information provided by Tim Beckett, the son of Mulberry inventor Allan Beckett and himself an engineer.
All of this valuable data was brought together and scrutinised over a period of almost eight months by the lab teams. They were thus able to recreate the Arromanches artificial harbour, offering a fascinating and informative journey into this part of the engineering genius behind the Normandy landings. Using the CATIA software developed by Dassault Systèmes for design, engineering and improvement of industrial products, they also modelled the Waco glider and LCVP landing craft, right down to the last nut and bolt, taking careful account of the materials used and how they would have behaved in real life.
For each of these three virtual simulations, the visual and emotional success of the interactive immersive experience was in no way achieved without compromising scientific and historical accuracy and entirely based on the available information. It is this dual objective that Dassault Systèmes believes makes the recreation such a valuable tool for historians, researchers, engineers and the public alike.
The Dassault Systèmes teams also identified, located and gathered all available data in order to create detailed 3D models of both the Waco glider and LCVP landing craft, right down to the last nut and bolt, taking careful account of the specific materials used and how they would have behaved in actual conditions.
The history of the Mulberry Harbour began with Winston Churchill, whose bitter experience of the Dardanelles campaign in the First World War had taught him the necessity of a port for the efficient supply and movement of men and materiel. The dangers of securing a defended port had been exemplified by the disastrous Dieppe Raid in 1942 and it was after this that Churchill wrote his 1942 memo demanding 'piers for use on beaches'. This was the memo that became Mulberry.
With a foothold secured on D-Day, the Allied invasion then required an extensive beachhead so that troops and vehicles could be offloaded. However, Normandy's key ports were firmly held and defended by the German Army. An artificial harbour was thus assembled off the coast at Arromanches — the first temporary deepwater facility of its kind ever devised and attempted. Major Allan Beckett of the Royal Engineers developed a system of floating metal roadways mounted on pontoon units of concrete or steel, which connected the beaches to the floating pierheads, further out to sea where large vessels could berth.
Thanks to legs that rested on the seabed but allowed these floating platforms to move up and down with the tide, operations could continue round the clock, which was a world first. The system used to join the floating sections gave them great flexibility, absorbing movements caused by sea swell and the weight of vehicles moving over them.
Kite Anchors
The 'kite' anchors, which moored the floating platforms to the seabed, were designed to dig in further when the cable is pulled, thus keeping the structure firmly in place throughout the landing operations. Lastly, huge reinforced concrete caissons were laid in a semicircle around the artificial harbour to form a breakwater, protecting it from tide surges and storm damage.
These technical innovations allowed the facility to be used at any time of day or night. By the end of July 1944, the Mulberry B at Arromanches was the world's busiest port in terms of traffic volumes. Some of the ideas first developed by Mafor Beckett are still used in marinas today.
Here again, the remnants of this impressive feat of engineering are slowly eroding away. Before all information is lost, the Passion for Innovation Institute and its labs have reconstructed these installations in an interactive and immersive virtual reality environment. The objective is not only historic, technical and educational, but also offers a sensory and emotional experience.
Tim Beckett makes it clear just how much this innovation means to him, saying: "I've been to Arromanches many times, but never like this. Following his father's footsteps, Beckett too became a consultant port engineer. He admits to using his father's example in his everyday work and makes it clear that these innovations have resonance everywhere today.
"I still use the inspiration of the Mulberry project," he says. "And I'm not the only one: you still see its influence in things like 'Roll-on, Roll-off' ferries; in the use of jack-up pontoons and floating caisson platforms. Obviously, it was a unique and uniquely important project that will probably never be repeated, but it still has echoes worldwide."
"Virtually reconstructing the Mulberry Harbour, the LCVP landing craft and the Waco glider brings to life one of the most exciting episodes of 20th-century history for the broadest possible audience, safeguarding this valuable part of our engineering heritage – a heritage that is gradually being lost," says Mehdi Tayoubi, Passion for Innovation Institute director & experiential strategy VP for Dassault Systèmes. "This project builds a bridge between the engineers of yesterday and today by preserving the memory of these remarkable technological innovations.
The result is a fitting tribute to the engineers of then and now."
Innovations of Overlord
LCVP
The Landing Craft, Vehicle & Personnel (LCVP) designed by American engineer Andrew Higgins offered various innovative features. Each LCVP could carry a platoon-sized complement of men and weapons. Its flat-bottomed hull allowed it to run right up to the shoreline. The platoon leader would drop the full-width bow ramp and the men would charge down onto the beach. Thanks to its second rudder blade, placed forward of the prop, it would then reverse itself off the beach and head back out to the supply ship for another load.
Waco CG-4A Glider
The Waco CG-4A glider was the aerial counterpart of the LCVP. It could accommodate 13 troops and weapons, plus pilot and copilot. Relatively small, light and manoeuvrable, as well as silent, the Wacos carried troops deep into Normandy's 'bocage' landscape in the early hours of 6 June to secure the inland areas and seize key objectives, such as villages, bridges and crossroads.
Whale
The dock piers were codenamed 'Whale'. These piers were the floating roadways that connected the "Spud" pier heads to the land. The roadways were made from torsionally flexible bridging units that had a span of 80 ft, mounted on pontoon units of either steel or concrete called 'Beetles'. Their unique ability to twist up to 45o gave them great durability. After the war many of the "Whale" bridge spans from Arromanches were used to repair bombed bridges in France, Belgium and Holland. .
Spud Piers
The pier heads or landing wharves at which ships were unloaded. Each of these consisted of a pontoon with four legs that rested on the sea bed to anchor the pontoon, yet allowed it to float up and down freely with the tide.
