Introduction

On June 6, 1944, nearly 160,000 fighting men from Britain, America, Canada and other Allied countries, landed on a stretch of French coastline held by the Germans. It was the largest amphibious assault in history and was combined with a targeted bombing campaign and the involvement of around 20,000 airborne troops. It was a pivotal moment in the 20th Century and, although the exact number is still debated, within 24-hours had cost the lives of some 4,400 Allied servicemen (Caddick-Adams, 2020). The day has become known as D-Day; a generic military term for any planned date, but such was the significance of the events of June 6, 1944, it has forever taken over the title.

There has been much written and discussed about this momentous day, and the years of planning that went into it. Such plans involved the expertise of a huge range of military, espionage, engineering, communication and scientific bodies. However, one branch of this latter group has often been overlooked. Wetland scientists, with an understanding of peatland formation and structure, played an absolutely crucial part in the planning and preparation for D-Day. In this paper we will look at just how important this knowledge was in hel** to ensure the success of the most famous battle in World War II.

Gathering Information

Operation Dynamo saw the evacuation of the bulk of the British Expeditionary Force (BEF) from the French port of Dunkirk, during the end of May and start of June in 1940. In total 338,000 men were brought back to England, 229,000 British, the remainder being French and Belgian (Hastings, 2012). Even before the last men were evacuated, Britain began planning for what it hoped would be the eventual, and inevitable, invasion of mainland Europe. Such planning involved gathering as much intelligence as possible about the French coast, where a landing would be most likely to happen.

Shortly after Dunkirk the BBC broadcast an appeal for postcards and family holiday photographs taken in France in the prewar years. 30,000 items arrived in the first post and eventually 10 million pictures were collected. Additional information was gathered in the following years including aerial photographs, whilst old guidebooks gave information on the tides and local currents. The French Resistance supplied intelligence on the build-up of beach defences (the so-called Atlantic Wall), and enemy locations (Ambrose, 2002). In 1941 a further source of intelligence was allegedly obtained through the drop** of 16,500 homing pigeons, by parachute, into occupied Europe. Each pigeon had a questionnaire attached to it which the finder was encouraged to complete. Nearly 2,000 of these pigeons, with completed questionnaires, returned to their lofts in Britain (Messenger, 2014).

Offensive actions against the Germans on the European continent were also conducted as early as 24 June 1940, through the formation of raiding forces, which were the genesis of the Commandos. To enable this the Combined Operations (CO) Headquarters was created and led from 17 July 1940, by Admiral Sir Roger Keyes until 27 October 1941, then Lord Louis Mountbatten, for a year, and then General Robert Laycock (October 1943–1947).

On 5 October 1940, Churchill officially ordered a plan to be prepared for major ground operations on the European mainland, with the aim of advancing into Germany. It was this directive which was the real starting point for the D-Day landings (Messenger, 2014) and led to the establishment of the Combined Commanders committee in 1941. This part-time committee consisted of a senior sailor, a soldier and an airman, and prepared papers looking at possible Allied landing areas for the British Chiefs of Staff (the most senior military personnel in the British Armed Forces). They concluded that any amphibious landing on Europe must be on a coastline that could be covered by Allied fighter aircraft, the beaches must be sheltered from the weather, and there should be a port nearby for easy landing of additional troops and equipment. These factors combined with the relatively weaker defences led them to suggest the coast north of Caen in Normandy was the best location (Messenger, 2014).

On 12 March 1943, Lieutenant-General Fredrick Morgan was appointed Chief of Staff to the, then-unnamed, Supreme Allied Commander (COSSAC) and tasked with producing a plan for the invasion of Europe: Operation Overlord. COSSAC took the advice of the Combined Commanders, developed it, and presented it to the Allied conference in Quebec in August 1943, where it was approved in principle.

Following this decision, Sir Trafford Leigh-Mallory, of the Royal Air Force (RAF), was appointed Overlord’s air commander; Sir Bertram Ramsay, Royal Navy, its naval commander; ground forces were commanded by Sir Bernard Law Montgomery, British Army; Sir Arthur William Tedder, RAF, was appointed Deputy Supreme Commander, and Dwight D “Ike” Eisenhower, United States Army, became Supreme Allied Commander. On 17 January 1943, Eisenhower took over from Morgan for the continued, detailed planning of Overlord.

Geological Intelligence

Once the Calvados coastline in Normandy, around 50-miles in length, had been selected for the Allies’ cross-Channel invasion, an immediate question needing answering was how stable was the substrate? Would the beaches, especially west of the mouth of the Orne River (which flows through Caen before discharging into the English Channel at the port of Ouistreham) support the weight and movement of the men, DUKWs (2.5-tonne six-wheeled amphibious trucks), tanks, bulldozer, trucks and other vehicles that would, hopefully, be landing in their thousands.

Some initial geographical and geological intelligence suggested that the beaches may not be able to, due to the significant erosion and movement of the coastline over the past centuries. Indeed, it was thought an old Roman port in the region had been two kilometres out to sea from the current shoreline. Four volumes of geological maps, smuggled out of Paris by the French Resistance are also believed to have raised serious questions on the makeup of the beaches. One of the documents was said to have been created by the Romans, when they had surveyed the entire empire for fuel sources. This survey indicated that there were extensive reserves of peat on the Calvados coast, which the Romans had extracted to burn (Ambrose, 2002). Due to the coastal retreat, since these times, the peat reserves now underlay significant areas of the Normandy beaches, and this could prove disastrous to the Allies’ plans.

The Problem with Peat

Peat is semi-decomposed vegetative organic matter. Peat makes up the substrate of peatland habitats, unique wetland ecosystems which cover just 3% of the world’s surface (Gorham, 1991) yet contain nearly a third of all the organic carbon found in the Earth’s soils. Peatlands have sequestered this carbon over millennia due, primarily, to the accumulation of partially decomposed organic matter (OM) in the anoxic conditions which suppress decomposition (Clymo, 1983). The mineral content of these wetland substrates is very low while the OM is generally higher than 75%. Although factors such as the source of the OM (vegetation), temperature and degree of humification (breakdown of OM) alters the specific chemical and physical properties of the peat, it is usually accepted that the higher the content of OM, the higher the compressibility of the peat and weaker it is in terms of stability (Cao et al., 2021). Indeed wet, undrained peat has been described as having virtually no measurable bearing strength, or capacity (Islam & Hashim,2009). The bearing capacity of soil refers to the maximum weight per unit area that a substrate can support without succumbing or being displaced. Wet peat generally has a bearing capacity below 70 kilopascals (Cao et al., 2021), one kPa, is a standard measure of pressure (along with a pascal; Pa) and is the pressure exerted by a 10 g mass resting on a 1 cm2 area, while a compact, dense sand and gravel mix has a bearing capacity over 600 kPa. The low bearing capacity of peatlands generally means vehicles need to be specially adapted to traverse them by ensuring weight is spread across as large a surface area as possible (Schröder et al., 2015).

In the preparations for D-Day, Professor John Desmond Bernal, a scientific adviser to Admiral Lord Louis Mountbatten, the Chief of Combined Operations, raised concerns about the presence of the peat deposits on the proposed landing beaches. It was clear the Allies needed to find out (1) where the peat deposits were and (2) if these peat deposits were capable of supporting men and vehicles.

Peat Bombing

To discover whether certain suspected areas of the Normandy coast were peat deposits, and other unsuitable substrate, such as clay, the Royal Air Force (RAF) was tasked with bombing them in a specific way. They then repeated this procedure on an area with suspected similar geological conditions on the Brancaster beaches in Norfolk, UK. Aerial photographs of the damage and craters created, at both locations, were taken and analysed to identify similarities (David,2021). The results were inconclusive. The only way the Allies could be sure of the makeup of the beaches was to physically analyse the sites.

Collecting Samples

In 1941 Lieutenant Commander Nigel Clogstoun-Willmott, an expert navigator in the Royal Navy, was in the Mediterranean attached to ‘Layforce’, a commando group deployed to the Middle East. Layforce was tasked with an assault on the Italian-held island of Rhodes (National Army Museum, 2024). Willmott had long believed that any amphibious attacking force needed in-depth knowledge of the type of beach they would be landing on, especially if heavy armour was required. He understood factors such as water gradients, obstacles, defences, beach bearing capacities and exits played an essential part in the success of any such operation. He, therefore teamed-up with Major Roger ‘Jumbo’ Courtney, a canoeist who had recently founded the Special Boat Section (SBS), partially with maritime reconnaissance work in mind, and undertook the first ever in-depth military beach reconnaissance. Willmott swam ashore near Rhodes Mandraki harbour collecting intelligence and substrate samples (David,2021), using improvised equipment and methods.

Despite the actual Allied attack of Rhodes being cancelled, Willmott’s mission and approach was praised. However, it was not until after the disastrous raid by, mainly Canadian troops, on the French port of Dieppe in August 1942, that the importance of Willmott’s ideas began to be recognised. Lord Louis Mountbatten, Chief of Combined Operations, asked him to form a team to assist with Operation Torch, the invasion of French North Africa (National Army Museum, 2024).

This ultimately led to the establishment of the Combined Operations Pilotage Parties (COPP) in early 1943, which had two main aims. The first was to carry out detailed covert reconnaissance of enemy-held beaches before a planned amphibious assault, including the collection of substrate samples. Secondly, on the day of the landing, they provided expert navigational assistance to the invasion forces (Crane,2020). Following work in the Mediterranean, COPP was tasked with hel** in the preparations for D-Day, and top of their list of activities was sampling the peatlands on the Normandy beaches, to be analysed by wetland scientists.

Sampling Beaches

In late 1943 Willmott was told scientists had concerns about the beach-bearing capacities of the Normandy landing beaches for heavy-wheeled vehicles and guns, particularly the section of coast where British and Canadian troops would land. These beaches were named Gold and Juno, respectively. The other beaches being the far easterly Sword beach (another beach the British would land on), and Utah and Omaha, on the westerly side, where the Americans would attack.

It was agreed COPP would land ashore covertly on December 31 to collect beach samples to be analysed, but not before a preliminary test had been performed at Brancaster, Norfolk. If COPP swimmers could swim ashore undetected then they would be permitted to go to Normandy. One of those performing the role of sentry that night would be Professor Bernal who did not believe COPP, or Coppists, as they became known as, could perform the correct sampling procedure undetected.

Forty-eight hours after being tasked with performing the test two members of COPP were ready to go. They were 24-year-old Major Logan ‘Scottie’ Scott-Bowden, and 25-year-old Sergeant Bruce Ogden-Smith, both coming from the Corps of Royal Engineers in the British Army. They swam ashore and collected substrate samples by using an auger to collect 10-inch (25.4 cm) cores, which were placed in metal tubes with phosphorescent numbers on their caps. Each man carried 10 of these tubes on a specially constructed bandolier. When ashore, under cover of darkness, the duo crawled in a ‘W’ pattern, collecting samples as they went, recording the sample’s position on underwater writing tablets strapped to their wrists (David,2021).

The auger used by the men is said to have been a spring-loaded device designed by Major Sir Michael Campbell, who held various water and land speed records. Some of the latter attempts had been performed on sand on Daytona Beach and Bonnevile Salt Flats, where Sir Michael had calculated the minimum depth of sand he needed for driving on was 14 inches (36 cm). For the D-Day landings these experiences were taken into account, and it was calculated that at least 10-inches of sand was needed over any peat or clay deposits to enable the landing to be a success. Whether the pair used a spring-loaded auger though is a topic of debate as there is the thought this may have made too much of a noise compared to a standard gouge or coring auger (Lawson, 2008).

Scott-Bowden and Ogden-Smith were successful in their test swim, collecting all the necessary samples undetected by any of the sentries, and their first mission to Normandy was set for New Year’s Eve.

The Normandy Beaches

The first survey of a Normandy beach by COPP in preparation for D-Day was named Operation KJH (Crane, 2020). The team, which included Willmott, Scott-Bowden and Ogden-Smith, left Gosport on the South Coast of England on the afternoon of December 31. Their target was an area west of Ver-sur-Mer, on Gold Beach.

After some discussions on how they would cross the English Channel and approach the beaches, they went in two motor gun boats (MGBs) and towed two smaller, shallow-drafted landing craft, known as LCPs (landing craft, personnel). At around 8pm they were 10 miles off the French coast and they transferred to the LCPs. Following various issues, including problems with the radio navigational aid and deteriorating weather, they finally stopped at 11pm, 400 yards (366 m) from the beach, in six-and-a-half feet (nearly 2 m) of water and directly opposite the Ver-sur-Mer lighthouse. Scott-Bowden and Ogden-Smith were both seasick by this stage but both went overboard and swam to the shore. The swim turned out to be much longer and harder than they anticipated due to the waves, currents and rising tide. They ended up further east than they had planned and opposite the village of La Riviere, where once ashore they could hear German soldiers celebrating the New Year. They walked west to their target beach area (Fig. 1) where they had to keep lying down every minute or so as the lighthouse beam swept over them (David, 2021).

Fig. 1
figure 1

The D-Day landing beaches and the location of the sampling site for Operation KJH

Full size image

Once at the desired beach they took the core samples in the same way as before. They found one of the patches of exposed peat that had been seen in the aerial photographs and tested the sand all around it. They then waded out into the surf and swam back out to sea. Reaching what they hoped was their rendezvous point they signalled with their torches fitted with a directional cone and waterproofed with a condom until they were picked-up by Willmott in the LCP at 12.27am in six-feet of water and 200 yards from the beach.

Both swimmers were exhausted and collapsed in their bunks when the LCPs finally met up with the original MGBs at 8.05am. The team arrived in Newhaven in the early afternoon and the samples were sent straight to London for detailed analysis.

Scott-Bowden reported that two augers and a fighting knife had been lost on the beach below the water’s edge, as the pair had struggled three times to get through the surf. He also reported that “whilst ashore, no mud, peat or other soft places were found”. This was confirmed with the analysis of the samples: they were all sand to a depth of 10 inches, and no signs of peat underneath (David, 2021).

It was concluded the beach could support the weight of tanks and wheeled vehicles.

Over the next few months Scott-Bowden and Ogden-Smith are said to have swum to and sampled so many beaches that they could not remember them all, though it is suggested they visited 30 locations (Howarth, 1959).

Their kit consisted of specialised waterproof suits, torch, compass, watch, underwater writing tablet, auger, receptacles for carrying the cores, meat skewers, sand coloured fishing line with a bead on it every 10 yards, a fighting knife and a 0.45 Colt revolver.

The fishing line and reel was made in Ogden-Smith’s father’s workshops, as his family made high-end fishing equipment. To take the core samples the pair would stick a skewer in the sand at the surf line and tie one end of the fishing line to it. They would crawl up the beach on their stomachs, probing for mines and unreeling the line. Every 10 yards (9.1 m) they took a sample, put another skewer in the ground and continued on a compass bearing (Ashcroft, 2008; David, 2021; Howarth, 1959; Lawson, 2008). One anecdote reports that at Omaha beach a German sentry tripped over the fishing line but fortunately didn’t see anything.

It is believed some of the beaches they surveyed were not on the invasion plans, so if the pair were captured they would not be able to say for definite where an invasion was going to take place.

Conclusion

It cannot be overstated how important the findings of COPP were to the planning and overall success of the D-Day beach landings. Indeed, the Allied naval commander, Admiral Sir Bertram Ramsay said: “On these operations depends to a very great extent the final success of operation Overlord.” It is understood that some of the areas of beaches they surveyed were found to be acceptable for wheeled vehicles, and other areas weren’t. In some cases specialised vehicles and tanks (so-called “Funnies”) were specifically designed to cope with the substrate conditions detected by members of COPP, such as the ‘Bobbin’ carpet layer, which laid its own path over soft clay, mud and peat (Imperial War Museum, 2024, and Howarth, 1959).

However, the COPP missions stem from an understanding of wetland science, in particular peatland science. Without Allied scientists highlighting the problems of the bearing capacity of peat substrate these missions may never have taken place and the subsequent landing plans changed accordingly to the benefit of the attackers. If large numbers of tanks, heavy armour, and supply trucks had become stranded in peat deposits on the landing beaches then the outcome of D-Day could have been very different. Indeed there is even the suggestion from Professor Bernal, writing after the war, that the intelligence gathered did not go far enough and even more could have been made of the surveys (Crane, 2020).

Knowledge of peat deposits in the landscape and intertidal zones, have been of importance for societies throughout history, and nowadays great effort goes into develo** detailed maps of such areas, such as Historic England’s, Intertidal and Coastal Peat Database (Hazell, 2008). Never has the detail and understanding of such information contributed so crucially to the success of a military operation on the scale of D-Day, and those that needed the information at the time clearly didn’t have access to the resources modern wetland and coastal scientists now have. The ability of the Allied teams, to collect the necessary data under the conditions they faced, and the analysis conducted, is astounding, and highlights the importance of acknowledging how different areas of science can have far reaching effects on society - in a similar way being promoted by the United Nations Educational, Scientific and Cultural Organization’s (UNESCO) Ocean Literacy project (UNESCO, 2024), which this story could easily feature in.

In summary, it is without doubt that an understanding of wetlands shaped the success of the climactic battle of the 20th Century. The efforts of those who collected and analysed the samples must not go unremembered.