Operation Sea Lion (wargame)

This article is about the 1974 wargame. For the planned Nazi invasion of Britain, see Operation Sea Lion.

Operation Sea Lion was a major wargame conducted at Royal Military Academy Sandhurst in 1974. Its aim was find out what might have happened had Nazi Germany launched Operation Sea Lion, 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). After the game's conclusion, the umpires unanimously concluded that the invasion was a devastating defeat for the German invasion force.

Scenario

The game was played using a scale model of southeast England, the English Channel, and northern France. Available troops and resources were based on known plans from both sides, and weather conditions were based on contemporary British Admiralty records that had, until then, never been published. The scenario assumed that the German military had taken until September to assemble the shipping necessary for a Channel crossing, and that the Luftwaffe had not yet established air supremacy. The Luftwaffe also had to continue to bomb London. As happened historically, in the main the Germans had only converted river barges available as transport ships.

Invasion

The German attack was launched at dawn on 22 September 1940 and consisted of 8,000 airborne troops and 80,000 infantry landed in amphibious operations. The invasion fleet suffered only minor losses to Motor Torpedo Boats, however the Germans lost about 25% of their unseaworthy barges. During this 24-hour period the Royal Air Force lost 237 aircraft (about 23% of its fighting strength), the Luftwaffe losses amounted to 333, also about 23% of its aircraft. Naval engagements were indecisive at this stage as the Royal Navy was still assembling its main destroyer fleet to attack. The larger ships of the Home Fleet (including battleships, heavy cruisers and aircraft carriers) were not to be committed due to their vulnerability to air attack and U-boats.

The Germans managed to advance a dozen or so miles inland and even captured the ports of Folkestone and Newhaven but the docks at Folkestone had been thoroughly demolished by the British rendering the port more or less unusable. British and Commonwealth forces were moved to fully engage in the battle with the first counter attack on 23 September, halting the advance of the Germans towards Hastings and recapturing Newhaven. German paratroops were also pinned down by long-range artillery and harassment by stay-behind forces. At this stage the Germans had few tanks and only light artillery ashore. An increasing shortage of ammunition was slowly forcing them back towards the sea. The Germans asked "Hitler" if the bombing of London could stop and the aircraft used to support the invasion. The request was denied. By dusk on 23 September the Germans had 10 divisions ashore, but most were halted by counter attacks or awaiting supplies and reinforcements.

The second wave of the German invasion was launched on the morning of 24 September, but only the short crossing from Calais and Dunkirk to Kent. At dawn on 24 September the second German landing, which was to include tanks and heavy artillery as well as supplies and men, was intercepted by a Royal Navy fleet of 17 cruisers and 57 destroyers plus Motor Torpedo Boats. 65% of the German barges, three German destroyers and seven E-boats were sunk for the loss of only two British destroyers (sunk by U-boats) plus two cruisers and four destroyers damaged. Some of the faster German ships broke away and headed for Folkestone, but the port was so badly damaged they could not unload. With the Royal Navy suffering only minor losses, the Home Fleet was ordered to stand by to sail for the English Channel. The German divisions ashore only had enough ammunition for 2 to 7 more days of fighting. Fast steamers and ferries were pressed into service to start an evacuation of German troops from Folkestone and Rye. "Hitler" ordered the remaining reserves to stand down and prepare for redeployment to Poland. Further British air and sea attacks disrupted the German evacuation over the subsequent four days. The remaining German troops in England finally surrendered on 28 September.

Conclusion

The German navy's relative weakness, combined with the Luftwaffe's lack of air supremacy, meant it was not able to prevent the Royal Navy from interfering with the planned Channel crossings. The Navy's destruction of the second invasion wave prevented resupply and reinforcement of the landed troops, as well the arrival of more artillery and tanks. This made the position of the initially successful invasion force untenable; it suffered further casualties during the attempted evacuation. Of the 90,000 German troops who landed only 15,400 returned to France. 33,000 were taken prisoner, 26,000 were killed in the fighting and 15,000 drowned in the English Channel. All six umpires deemed the invasion a resounding failure.

External links

Short summary of the Sea Lion wargame.