Operation Sea Lion: The Invasion Itself

[theirishdreamer]

yes

I was doing a Sealion trawl a short while ago and its one of the best TL's Ive read on the subject, I really enjoyed it. And best of all you keep it all very plausible and realistic which many Sealion threads wave goodbye to fairly early on.

 

[Bees]

Hate to not add to the actual discussion, but I agree with the previous two posters. It was a great timeline.

 

[Midnight-Blue766]

According to Wiki:

According to captured German documents, the commander-in-chief of the German Army, Walther von Brauchitsch, directed that “The able-bodied male population between the ages of 17 and 45 will, unless the local situation calls for an exceptional ruling, be interned and dispatched to the Continent”. This represented about 25% of male citizens. The UK was then to be plundered for anything of financial, military, industrial or cultural value, and the remaining population terrorised. Civilian hostages would be taken, and the death penalty immediately imposed for even the most trivial acts of resistance.
The deported male population would have most likely been used as industrial slave labour in areas of the Reich such as the factories and mines of the Ruhr and Upper Silesia. Although they might have been treated less brutally than slaves from the East (whom the Nazis regarded as sub-humans, fit only to be worked to death), living and working conditions would still have been severe.
In late February 1943 Otto Bräutigam of the Reich Ministry for the Occupied Eastern Territories claimed he had the opportunity to read a personal report by General Eduard Wagner about a discussion with Heinrich Himmler, in which Himmler had expressed the intention to kill about 80% of the populations of France and England by special forces of the SS after the German victory. In an unrelated event, Hitler had on one occasion called the English lower classes "racially inferior".

 

[oldironside]

'In an unrelated event, Hitler had on one occasion called the English lower classes "racially inferior".'

He wasn't exactly blessed with a sense of irony, was he.

 

[theirishdreamer]

ummm

Yeah the Germans were nuts, planning for all sorts of lunacy. Don't worry Sealion is plausible with circumstances to go ahead but it was going to fail miserably. The Nazi's would have been better planning there operations, such as getting past the royal navy rather than writing volumes on how'd they'd run Britain and Ireland.

 

[MattII]

Assuming the landing is feasible logistically then after the initial assault there would be a period of consolidation as the Germans got the ports repaired and brought in their heavy equipment. During this period the British would redeploy their forces to bring the greatest pressure on the Beach heads and try to drive the Germans into the sea (hampered no doubt by the victorious Luftwaffe).

The slight issue with this is that the Luftwaffe are going to be drawing from the same resources as the army, and there will be a period where they have to rebuild the runways, so a victorious Luftwaffe over occupied Britain is not a given.

 

[Dathi THorfinnsson]

i think the idea of this thread is to ignore the impossibility of Sealion and discuss what directions it could go in IF it were successful, or what the German war aims would be upon invasion (where they'd hit first and then the following objectives, etc.)

Ie, ASBs transport and supply the German army? Then this is the wrong forum.

 

[theirishdreamer]

yeah

Sealion succeeding belongs in ASB as even if the British fight like complete idiots and German like warlord geniuses the logistics aren't there to maintain a structured invasion. The Heer can get ashore in an invasion - they just can't supply said forces after a few day as the RN will flood the channel after any such landing. Even the German plans themselves relying upon the British (and in Green the Irish) to just simply give up after the first fighting on the beaches or at worst after a "decisive" battle inland somewhat. That wasn't going to happen so I'm inclined to discuss how to get the invasion to go ahead, which is plausible on what we know of German leadership in the war; and of the impact of the failure of such expensive operaion.

 

[Meadow]

Ie, ASBs transport and supply the German army? Then this is the wrong forum.

No, 'ie' we handwave the initial landings and discuss what likely battles would occur inland. That being said, without a believable chain of logistics it's hard to tell what the Germans will seek to (or be able to) attack first.

 

[theirishdreamer]

well

The Germans have to push inland towards London hard and fast, and they know it themselves theyve got a supply issue.

The first real battles will be the massive air battle and the falshmigher landings.

To get the invasion to go ahead you need to keep the Kriegsmarine surface fleet intact rather than mostly destroyed after Westerbrung. It won't do f all good in reality but in the Nazi mindset (which was willing to attack the RN with a few destroyers, eboats and Uboats) its a new Spanish Armada.
​

 

[Alex1guy]

Even ignoring the RAF/RN, the invasion will stall under its own logistical weight. Add to that the increasing resistance on the ground as British formations move to the beachhead, and the Germans aren't going to get much further past their initial lodgements.

Yeah the thing is you can't advance without supplies. Men need food and ammo and if that ain't coming, the invasion goes nowhere even if they get ashore. Poor Germans...

I was doing a Sealion trawl a short while ago and its one of the best TL's Ive read on the subject, I really enjoyed it. And best of all you keep it all very plausible and realistic which many Sealion threads wave goodbye to fairly early on.

Gah! I love you I've been looking for this Timeline I forgot it's name thank-you!

 

[New Yorker]

I've never been able to find much information on what the UK government's plans were in the event the Germans threatened London.

I've read a few things about manor houses being readied for the Royals and the government and that such houses were in a line, more or less, from London to Liverpool so that the Royals and the government could leave for Canada.

Does anyone know much about such preparations? Perhaps a book on the subject?

 

[sitalkes]

I think the first thing to fall would be the German lodgement in Kent. If the Germans did wrong-foot the RN and RAF on day one and get ashore I doubt they'd be able to sustain the lodgement logistically. Fighter Command would contest the skies over the lodgement allowing Bomber Command and the Home Fleet to cut the German transport across the Chanel. This battle would only take a couple of days to sort out, then the Germans would be stranded in Britain.

Exactly how many bombers would be left to bomb the Germans? Bomber Command continued to bomb Germany etc in daylight during 1940 and often suffered 100% casualties (though it suffered few casualties in night raids). The light bombers were massacred during the French campaign. The Sealion plan included the bombing of the bomber bases on the last days before the invasion.
From July till the end of the year, Bomber Command suffered the loss of 1400 aircrew and lost 330 planes. In August/September 1940, No. 4 Group (with five squadrons) took part in eight attacks on Berlin, though it could not muster more than a dozen aircraft in a night. Army Co-operation Command could muster 7 Blenheim squadrons, but two of them were Blenheim fighters (which had their bomb bays covered by four .303 machine guns, giving them an offensive armament of five rifle-calibre machine guns) and they could only muster 3-4 serviceable machines per squadron.
Bombing was very inaccurate, bomb sights were rudimentary, and a lot of bombs failed to detonate as many had warheads made of amatol, which was an inefficient explosive.

 

[jlckansas]

Occasionally you will hear of some farmer or someone building a structure that requires digging coming across a hide of some sort down in southeast England. These can be anything from a simple culvert type structure sealed up to a more elaborate living quarters type arrangement. IIRC some of these have actually had stored weapons and explosives in them. What people do not realize is that some of this was built by people that only a set number of them new of locations and what was there just in case, and this carried over into the cold war era.

 

[Ultimate Paragon]

'In an unrelated event, Hitler had on one occasion called the English lower classes "racially inferior".'

He wasn't exactly blessed with a sense of irony, was he.

Or a sense of foresight.

 

[sitalkes]

The Germans have to push inland towards London hard and fast, and they know it themselves theyve got a supply issue.

The first real battles will be the massive air battle and the falshmigher landings.​

To get the invasion to go ahead you need to keep the Kriegsmarine surface fleet intact rather than mostly destroyed after Westerbrung. It won't do f all good in reality but in the Nazi mindset (which was willing to attack the RN with a few destroyers, eboats and Uboats) its a new Spanish Armada.​

If you add up the port capacities of Newhaven, Ryde, Dover and Folkestone and add some air-dropped stores plus the beach capacities, then you do not have a supply capacity problem. If Deal is taken, that adds a sheltered beach that was once Britain's busiest port. Beaches can be used because there was bad weather on only five days between September 19 and October 20. The piers at Brighton and Hastings can be repaired easily as they only had one span blown up. Beaches were the major source of supplies for Overlord until they took Antwerp. The troops in the first wave would have landed with five days' supplies anyway. the beach capacity was several times that needed by the troops so extra stores could be landed on good weather days to make up for the bad weather days. Supplies only had to be carries a short distance once landed, even to London was only 40-50 miles.

The problem with supply capacity comes when the second wave lands, as the capacity needed would then nearly double, so the second wave must capture Southampton/Portsmouth and/or other ports as soon as possible, as by the time it lands it may not be able to use the beaches at all.

The map shown is for the initial Army plan, which was changed to have an invasion area between Brighton and Folkestone only (but not including those towns), though the objectives were the same and if shipping could be found somewhere the other army group might have been deployed.

The first wave was supposed to take the first objective line and then hold it for up to 10 days while the third echelon is landed along with the air-landed division. The second wave would then start arriving. It took three days for the British counter-attack to arrive at the beaches without opposition in a 1941 exercise but that still leaves up to a week when the troops have to fight without significant reinforcements against a steadily reinforced opponent. The first wave had about 350 armoured vehicles and air superiority but whether it would have been possible to hold out for that long nobody knows.

The invasion fleet consisted of 3-4,000 vessels, not just a few destroyers. The escorts alone were not expected to stop the RN. There was a layered defence consisting firstly of 40 U-boats plus aircraft , then minefields plus aircraft (plus coastal guns at the eastern end), then escorts plus aircraft. They did not have to fight the entire RN, just the Nore and Portsmouth commands, which was quite a considerable force i.e. one old battleship, 50 destroyers (mostly first world war types) and light cruisers, and hundreds of smaller ships and boats.

The campaign may have been a short one. How many government members had Churchill's backbone and inspirational qualities? How many had previously been appeasers? Churchill had to face two votes of no confidence - just for losing Tobruk and Singapore. Then he was voted out of office before the war was over. What might his political enemies have tried if London was under threat? Churchill loved to be in the frontline and would go up on the top of his building to watch the air raids. He might have been killed by bombs or fighting in the front line - as in this story...

“Later that afternoon with the Germans already in Trafalgar Square and advancing down Whitehall to take their position in the rear, the enemy unit advancing across St. James 'Park made their final charge. Several of those in the Downing Street position were already dead... and at last the Bren ceased its chatter, its last magazine emptied.


Churchill reluctantly abandoned the machine-gun, drew his pistol and with great satisfaction, for it was a notoriously inaccurate weapon, shot dead the first German to reach the foot of the steps. As two more rushed forward, covered by a third in the distance, Winston Churchill moved out of the shelter of the sandbags, as if personally to bar the way up Downing Street. A German NCO, running up to find the cause of the unexpected hold-up, recognised him and shouted to the soldiers not to shoot, but he was too late. A burst of bullets from a machine-carbine caught the Prime Minister in the chest. He died instantly, his back to Downing Street, his face toward the enemy, his pistol still in his hand”

In any case, IOT the invasion was impossible because it could take place no later than late September, which means the Battle of Britain had to be won by the first week in September, which means the main part of the Battle of Britain would have had to have started about a month earlier... so Germany had already lost the war when the BoB started.

 

[CalBear]

Failures in order?

Unarmed paratroopers get slaughtered by everything from Lewis guns Enfields to farmer's shotguns. Figure 50% losses, no chance to concentrate.

Minimum 30% losses in the Channel before the landing force een gets close to the shoreline. Major losses in armor and vehicles as larger vessels draw special attention from the RAF and RN.

Lack of proper naval gunfire and air support leaves significant number of troops trapped on the beach subject to mortar fire and RAF/FAA attack.

1st Wave losses on D-Day, Bomber Command & FAA attacks on loading docks, continued air and surface attack in the Channel interdict 60-70% of initially planned supplies from reaching beach on D+1. The impact of this is somewhat mitigated by the fact that losses in the invasion force are now running close to 40% (although far too late it has suddenly occurred to Reich planners that the "Home Guard" is primarily made up of WW I combat veterans who know how to do two things, dig like bastards and hold a fixed position until over-run).

D+2 finds surviving paras running out of pretty much everything but guts. Minimal resupply drops have made it through the RAF, with many drops falling outside of the Heer areas of control. Available water transport is down to roughly 15% of D-Day figures due to combat losses, weather/sea state related losses and mechanical breakdown. Most of the riverine craft that were pressed into service have begun to suffer mechanical issues from extended exposure to salt water (people tend to forget this one, fresh water vessels are not designed to deal with the far greater corrosive effects and salt water ingestion into machinery that are designed into seaborne vessels).

Supply situation, especially lack of ammunition/medical supplies begins to stop what units have managed to get inland in their tracks.

D+3 aircraft with small arms and ammunition, begin to arrive from the U.S. under executive order from FDR (in keeping with U.S. law at the time, the surplus value of the rifles is paid for by transfer of funds between British government accounts and the Federal Reserve, while aircraft are flown by "Canadian" pilots) While primarily rifles, and in .30-06 caliber, the weapons are of limited utility although they do provide equipment for newly formed Home Guard units. They include a large number of M1917 Rifles. a U.S. made version of the British Pattern 1914 Enfield, in some cases these weapons have literally been removed from the arms lockers of U.S. army Chemical Mortar companies and shipped by rail to Canada. By D+8 some 80,000 M-1917 and 1.2 million rounds of ammunition have arrived (Congress approves a modified version of Lend Lease on D+10)

Small units of Heer troops begin to surrender due to lack of ammunition and seeming lack of support.

D+5 to D+8. Increasingly desperate, heroic efforts by KM units to provide supplies to expeditionary force continue with whatever vessels can be found. A final, all out effort to secure Portsmouth harbor to facilitate movement of supplies is defeated on D+7.

D+14 With losses running over 85% KAI/WIA/MIA/PoW senior surviving Heer officer formally surrenders his command to Field Marshall (later 1st Viscount Alanbrooke) Alan Brooke. Due to poor communication and the scattered nature of the Heer formations it is nearly two weeks before the final German troops are under British control.

The horrific losses, especially in Luftwaffe fighter and transportation formations suffered in Sealion prevent Hitler from coming to the aid of his Italian allies in North Africa and Greece as all remaining forces are needed for the upcoming Operation Barbarossa.

In November 1940 FDR is elected to an unprecedented 3rd Term as POTUS. He captures 54.2% of the vote and wins the Electoral College by an overwhelming total of 442 to 89.

 

[Otis R. Needleman]

If you are interested in an alternate history of a somewhat more successful Sealion, read S-Day, by James Stewart Thayer. Came out in 1990. Might be in some libraries, available used very cheaply on Amazon.

I enjoy books that make me think. This book made me think.

 

[TheYoungPretender]

'In an unrelated event, Hitler had on one occasion called the English lower classes "racially inferior".'

He wasn't exactly blessed with a sense of irony, was he.

We're going to ding him because he didn't pick that attitude up at Eton alongside everyone else who usually expressed it?

More on task though, didn't the British have block ships and demolitions ready to go on most of the port facilities on the Southern coast? Even if the paratroops grab the harbors, they may have precious little they can do with them.

 

[Evermourn]

Hey thanks, it's always pleasant to read comments like this.

I think I've read the whole thing about 3 times, it's one of the best AH timelines I've read. The Germans seem to hang on a little longer than they should given their supply limits, but I got the impression that was to make for a slightly longer story than "They landed, 3 days later that was it."