D-Day: A military operation like no other
Our Chief Executive, Adrian Bell, writes about the extraordinary planning, preparation and coordination behind the largest amphibious invasion of all time.
About 5 miles to the north of Portsmouth lies Southwick House. Today, it's the Defence School of Policing and Guarding but, in early 1944, it became the headquarters of the main Allied commanders: General Eisenhower, Allied Supreme Commander, Admiral Ramsay, Naval Commander-in-Chief and General Montgomery, Army Commander-in-Chief.
Although still a defence establishment, Southwick House opens its doors around the anniversary of D-Day every year and is well worth a visit. One of the most significant artefacts is the original and unique Grade I listed painted wooden D-Day map.
The map
The map fills an entire wall within Southwick House, from floor to ceiling and side to side. It shows the south coast of Britain and the north coast of France and details ports of departure, landing beaches, convoy routes, minefields, tidal conditions, drop zones and more.
It was used both to monitor progress and to brief VIPs including King George, Churchill and de Gaulle.
It is said that the two carpenters who made the map in early 1944 were, on completion of their work, incarcerated benignly until after the invasion, less they spilled the secrets they had become so much a part of.
"It is said that the two carpenters who made the map in early 1944 were, on completion of their work, incarcerated benignly."
The Mulberry harbours
Eighty miles to the West of Southwick House is Portland Harbour in which lie two Grade II listed reinforced concrete caissons. These were built to create the artificial Mulberry harbours which were assembled as part of the follow up to the Normandy landings.
As the Germans held all the significant ports on the French coast - and ports were vital to the resupply requirements of the troops who were landed ashore - 213 of these caissons (or Phoenix as they were called) were manufactured in docks throughout the United Kingdom.
These were then towed down to the South Coast and across the English Channel by tugboats that could proceed at only just over 4 knots or about 5mph.
Some of these caissons had to travel all the way from construction ports on the West Coast of Scotland. Therefore, because of their slow pace, they needed at least six days from moment of departure to arrival of the north French coast.
Once these caissons had departed their original docks, they were very vulnerable to attack and, just as important, enemy reconnaissance activity. Detection could have undermined the secrecy so vital to success. Coordination and timing were key.
"Coordination and timing were key."
Beach surveys
Well before landing craft could run up the beaches of Normandy and before the Mulberry harbours could be created on the coast, beach surveys were required to determine the detailed information concerning geology, hydrography and sea conditions.
To do this, a special team of hydrographers was created in October 1943. This team worked under secretive and very hazardous conditions from November 1943 to January 1944 to collect the precious data.
"A special team of hydrographers was created in October 1943."
Operation Order
The coordination and control of all this activity was a huge task and a very detailed and highly secret Operation Order was produced. This ran to some 700 pages and included details for all participants, from tugboat skippers through landing craft coxswains, to beach masters.
Each received their own particular subsection detailing exactly what they had to do.
These operation orders were collated, typed and dispatched by a small army of WRNS working under conditions of utmost secrecy.
"Each received their own particular subsection detailing exactly what they had to do."
Operation Fortitude
Also crucial to the success of the Normandy landings was Operation Fortitude, a large-scale military deception operation with the aim of misleading German High Command as to the location of the invasion.
This forced the Germans to pour resources into the defence of Calais as the shortest and most obvious route across the English Channel.
"This forced the Germans to pour resources into the defence of Calais."
The weather
The weather played its part. Despite being summer, wind conditions on 5th June - the original date for the landings - were atrocious and so D-Day had to be delayed.
The options were limited. Tidal conditions would only remain favourable until the 6th June, or everything would have to wait two weeks to the 18–20th June. A delay of that length would have required the recall of men and ships, many already in place or moving.
Such a delay was a huge concern to Admiral Ramsay as it could have caused chaos given the intricacy of the planning effort and would have increased the risk of German detection, thereby endangering the success of D-Day itself.
"Wind conditions on 5th June - the original date for the landings - were atrocious and so D-Day had to be delayed."
Military personnel
On the day, 7,000 ships and landing craft and 198,000 naval personnel supported by over 14,000 allied air sorties, were involved in landing some 156,000 troops on the five beaches in Normandy.
Within a few days, 326,000 troops, 50,000 vehicles and 100,000 tonnes of stores and equipment had been landed. But this was not without cost, there were over 10,000 casualties and 4,000 dead in the same period.
By the end of June, over 850,000 men and 150,000 vehicles had been landed, my grandfather among them.
"There were over 10,000 casualties and 4,000 dead."
Small cogs
When talking to veterans about their experience of D-Day, many often dismiss or trivialise as unimportant the part they played. Many say that they were no more than a small cog in a huge enterprise.
However, when we take a step back and consider the scale and the ultimate success of that operation, it could not have succeeded without such commitment from so many people playing their part. This was an operation the like of which had never been done before and has never been done since.
"Without each and every one of them it is likely that the eventual success would not have been forthcoming."
We salute them all
And we should think of this massive contribution, not only in terms of the brave soldiers who landed and fought their way through Europe, but all those others who played their part.
From the chippies who created the wall map, the typists and dispatchers of the operation order, those involved in the construction and deployment of the caissons, those in the deception of the enemy, and so the list goes on... all the way through to the Commanders who planned and led the operation.
Yes, many might consider themselves to be ‘just a small cog’, but without each and every one of them it is likely that the eventual success would not have been forthcoming.
We salute them all and the part these brave men and women played, not just in the invasion but also in the ultimate defeat of Nazi Germany and the liberation of Europe.
Read more
Our D-Day Navy veterans
Thomas, Joe and Bob were just teenagers when they crossed the channel on ships providing vital defence support.
Our D-Day Army veterans
Harry, John and Richard were amongst the 150,000 brave soldiers who risked their lives on the beaches of Normandy.
Our D-Day RAF veterans
Syd, Harry and John played crucial roles in the invasion from the air and will never forget their experiences.
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