Operation Sealion – Part 8

Blown Periphery, Going Postal

The Sandhurst Wargame and final notes

The debate on the viability of a German invasion of the British Isles has continued and probably will continue for many years to come. In 1974 the Royal Military Academy Sandhurst conducted a major wargame to find out what might have happened had Nazi Germany launched Operation Sealion, their planned invasion of southeast England during World War II, in September 1940. The wargame was organized by the Daily Telegraph and Dr Paddy Griffith from the Department of War Studies at Sandhurst.

The British umpires were Air Chief Marshal Christopher Foxley-Norris, Rear Admiral Teddy Gueritz and Major General Glyn Gilbert. The German umpires were General Adolf Galland (air), Admiral Friedrich Ruge (naval) and General Heinrich Trettner (land). Each team consisted of four players: air, land, sea and political. Rudolf Rothenfelder, President of the Fighter Pilots Association in Munich and ex-Luftwaffe officer played “Goering”; Professor Rohwer, Director of the Military Institute in Stuttgart, played “Raeder”; and Brauchitsch was played by Colonel Wachasmuth, the Bundeswehr liaison officer at the Staff College. The German players were supported by their Defence Attaché in London, Admiral Schuenemann. Churchill was played by Brigadier Page, Assistant Commandant of the RMA Sandhurst. The people who played The British Home Forces Commander-in-Chief, General Sir Alan Brooke, and the First Lord of the Admiralty, Dudley Pound, are not recorded. The game had a total of 30 participants.

For the game’s pre-preparations there was a computerised Battle of Britain phase, the computer being 1970s technology filled an entire large room. The Battle of Britain phase lasted several days and during this time, the main players were given their briefs as to what was known, what was expected of them and how they should behave. There were a total of seven umpires. Controversial or ambiguous occurrences were vigorously debated among the umpires. The main game was played using a scale model of southeast England, the English Channel and northern France. Troop dispositions were based on known and recorded plans from both sides and the game would cover one week of the campaign, which was felt to be long enough to establish an outcome. Weather and sea conditions were historic data compiled from the Met Office and Admiralty records.
The subsequent controversy would centre round the area of the ground, the ubiquity of the umpires and the initial planning assumptions which were:

• The German military had taken until September to assemble the shipping necessary for a Channel crossing.
• The Luftwaffe continued to attack British airfields after September 7, 1940 instead of bombing London but despite continuous attacks up to September 19 had not established air supremacy.
• The Luftwaffe bombed London.
• The Germans had only converted river barges available as transport ships. Not a great deal was known about the invasion fleet at that time. This represents a gross simplification as the shipping involved nearly 4,000 vessels, including 150 merchant ships and 237 light or auxiliary close escorts, in four invasion fleets.
• The only ships available to defend the invasion fleet were some U-boats, E-boats and destroyers.
• The invasion fleet was largely unmolested in the crossing, as the Royal Navy ships had to steam south from their bases as far away as Scotland to reach the invasion beaches.
• The bombing of London would destroy railways between East Anglia and the invasion beaches in Kent and Sussex, so that British troops could not be redeployed quickly. This actually happened on September 7, 1940, when all the railways running south from London were cut and took a long time to repair due to the use (for the first time) of delayed action time bombs.
• Operation Herbstreise was enlarged to make 10,000 men available for a landing in East Anglia, northern England, Scotland, or Iceland (in real life there were three divisions of infantry involved).
• The Channel Guns have no effect.
• The Home Fleet will send its capital ships south. In real life, both Admiral Forbes, commander of the Home Fleet, and Dudley Pound, First Sea Lord, said they would not send capital ships into the Channel unless the Germans did so, too.

Paddy Griffith the chief umpire was very disappointed with the map, which he said was unnecessary and on which he wasn’t consulted. “On the day of the game its mere existence had the instant, deeply unfortunate effect of revealing to the British team that the invasion would certainly land in Kent, rather than in East Anglia, or wherever else the umpire team had been trying hard the German’s deception plan sound convincing.” The map only included the English coast between Portsmouth and Ipswich, and should have at least included East Anglia, as that is where the real British high command expected the invasion.

The game time commenced on 19th September 1940 and the Germans decided to postpone invasion because the seas were too rough. The first two days of the game consisted of mainly air battles with the movement of British ground units to the coastal zones. The Luftwaffe bombed Britain’s south coast and laid mines in the Harwich, Humber and Thames estuary waters. The Germans landed their Herbstreise diversion force in Iceland and laid protective minefields to protect the coastal traffic and landing areas. Churchill refused to divert any troops to counter the Iceland invasion.
On the afternoon of September 21, the wind dropped, and the forecast for the next day improved. The German protective minefields were finished, stretching out from the North Foreland. The first wave invasion fleets began to form up at dusk, and begin to cross. They were not spotted by the British until 11pm, The Cromwell warning was issued half an hour later (and the church bells rung), and at midnight the Home Fleet was ordered south.

The Germans landed at dawn on 22nd September with 8,000 airborne troops and 80,000 infantry. The invasion fleet suffered minor losses to motor torpedo boats (MTBs), but the Germans lost a quarter of their seagoing barges due to weather and RAF bombing. In the first twenty-four hours the RAF lost 273 aircraft, nearly a quarter of its strength. The Luftwaffe lost 333. The RN was not fully committed at this stage as the destroyers were assembling and the capital ships would not be committed in the Channel due to the threat of U-boats, mines and air attack.

By the end of the first twenty-four hours the Germans had advances up to twelve miles inland and had captured the ports of Folkestone and Newhaven, although port facilities had been demolished by the retreating British. German paratroops were pinned down and harried by the special units of the Home Guard and the Germans had only landed a small proportion of their artillery and tanks. The Germans requested that the bombing of London could cease so that the bombers could support troops ashore. “Hitler” refused this request. By dusk on the 23rd September the German had ten divisions ashore, but they were awaiting supplies and reinforcements.

The second wave carrying heavy support weapons and supplies was launched on the 24th September was intercepted by the RN’s fifty-seven destroyers and seventeen cruisers, plus MTBs. The Germans lost 65% of their barges, three destroyers and seven E-boats. The captured British ports were so badly damaged, the German ships were unable to unload. By now the Germans only had enough ammunition for a maximum of seven days fighting and ferries were pressed into service to evacuate the German troops. The RAF and RN continued to harry the German naval units, with the Home Fleet awaiting the orders to sally into the narrow Channel. German troops remaining on British soil surrendered on 28th September.

The Sandhurst Wargame given its preliminaries and assumptions produced a result that could have been entirely predicted. However there remains criticism of some of the planning assumptions and the scope of the game. By limiting the area of operations to the immediate Channel and south-eastern England area, the German players were immediately constrained in their courses of action. Actual Sealion planning considered a forward staging area in the Republic of Ireland and a feint naval action out of Denmark to draw the RN’s destroyers and cruisers away from the Channel.
Moreover, there was no mention of the German VI Army’s planned landing in Lyme Bay nor the landings by the IX Army around Portsmouth and Brighton. The German Army of 1940 fought a war of manoeuvre and it is unlikely they would have poured their entire effort into the well-defended south-eastern sector of the British coast. The game’s German ship list made no mention of the over 100 ferries, freighters and cargo ships that the Germans had assembled in the ports adjacent to the Channel ports for phase two of the landings. However, these ships would have required an operational port with intact facilities to unload. The assumptions of the Sandhurst game was that the Germans never achieved this objective.

Blown Periphery, Going Postal

However, even nearly eighty years later, the questions and doubts remain regarding Operation Sealion. Only one 11 Group fighter station was put out of action during the Battle of Britain, RAF Manston. Only the RAF’s No 11 Group was fully committed to the battle and British fighters were rolling off the production lines faster than pilots. But Dowding was slow to commit the Poles and Czechs to the battle and they proved themselves to be incredibly effective. There were still many pilots of the Fleet Air Arm who could have been committed. Why did Hitler order the Bombing of British Cities? Because he was a corporal from the trenches with no grasp of air or naval tactics, or the primary principal of warfare, the selection and maintenance of the aim. Why didn’t the Luftwaffe fit drop tanks to their BF 109s? They did exist but in insufficient numbers. Knowing the type of offensive counter-air action they would be conducting, why wasn’t production immediately increased? Why did Goering order his fighter pilots to be constrained with close escort of the bombers?

Blown Periphery, Going Postal

Of course all of this is tempered with hindsight, but in 1940, could the Imperial General Staff be sure that a German invasion was unlikely? Whatever the ifs and buts, is it likely that had the Germans landed on British soil, the result would have been a great deal bloodier and more costly to both sides than the results of the Sandhurst Wargame.
Let the arguments and debate continue…
 

© Blown Periphery 2018
 
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