Operation Sealion

[gaxsax]

German Field Marshall Mainstein writes that an immediate invasion of Great Britain after France's defeat was the right strategy. The British were in disarray and the failure to destroy or capture the British Expeditionary Force (BEF) was a fatal mistake. He further writes that the Royal Airforce and Royal Navy had to be reduced to to 'sufficient level' for duration the operation. The destruction of the RAF was not required. It led to Britain's strength and strayed from the German all-arms strategy of warfare.

What does the forum think?

[Richard Anderson]

What does the forum think?

Do a search for "Sealion" or "Seelöwe" and "What If".

[pugsville]

German Field Marshall Mainstein writes that an immediate invasion of Great Britain after France's defeat was the right strategy. The British were in disarray and the failure to destroy or capture the British Expeditionary Force (BEF) was a fatal mistake. He further writes that the Royal Airforce and Royal Navy had to be reduced to to 'sufficient level' for duration the operation. The destruction of the RAF was not required. It led to Britain's strength and strayed from the German all-arms strategy of warfare.

What does the forum think?

With What?

The Germans had no amphibious warfare capability or experience. The Kriegsmarine had suffered massive losses during the Norwegian campaign. There simply was no capability to land large numbers of troops, it would take months even to organize an emergency scratch build wholly inadequate barges/transport based invasion like they did. Any 'immediate' operation would a a couple of divisions, just massively short of the numbers required for an successful operation. And be relying some enormous luck to cross the channel without opposition (which was incapable or resisting) let alone maintaining supply across the water,.

The Ju52's suffered large losses in the airborne operations in the low countries. For both ground support and anti shipping operations the Germans would be relying on the Ju87 Stuka, The Ju87 and Ju52 were extremely vulnerable to enemy fighters and really needed air superiority /dominance to operate. Against an integrated air defense system (which the Germans juts failed to understand and appreciate) the British had with radar and the large reserves of aircraft the British had not committed to France, German operations with these aircraft would be seriously compromised, while the RAF and air defense system remained intact.

The German naval resources were just pitiful, the germans had so few forces that it was incapable of defending or maintaining any invasion force or supply land by sea. Not just outnumbered by totally overwhelmingly outnumbered. Any naval battle would be a one sided massacre. Which leaves the Germans somehow relying on the Luftwaffe to negate the Royal navy. Which was not possible while the RAF remained substantially intact. And there are serious questions about the anti shipping capability of the Luftwaffe with no torpedoes, no bombs capable of penetrating capita ship armor, virtually no training or experience in anti Shipping roles. And no real way of defending the invasion fleet or resupply fleet at night.

https://en.wikipedia.org/wiki/Norwegian ... n#German_2

"The German losses at sea were heavy, with the sinking of one of the Kriegsmarine's two heavy cruisers, two of its six light cruisers, 10 of its 20 destroyers and six U-boats. With several more ships severely damaged, the German surface fleet had only three cruisers and four destroyers operational in the aftermath of the Norwegian Campaign"

[HistoryGeek2019]

The entire German surface navy consisted of something like 5 destroyers and 1 cruiser after the Fall of France. Britain would have happily allowed Germany to sail its army across the Channel in river barges, then blown all their supply ships out of the water.

[Barrett]

Next year's the 80th anniversary of the BoB, and there's discussion of how Sealion might have gone--or not. IMO the most overlooked subject is Germany's almost total lack of bow-ramp landing craft. Nothing but a couple of prototypes, near as I can tell, by the time Der Tag came and went. Certainly nothing resembling LCIs or LCMs, let alone LSTs.

So: how would the Wehrmacht get heavy equipment across the beach?

Evidently some Mk II Panzers were equipped with swimming kits, however effective they might have been (recalling the DD Shermans 4 years later.)

Seems that the Germans needed to seize at least one or two Channel ports intact, and THAT was not likely to happen.

Any thoughts on German phibs gladly received!

[HistoryGeek2019]

For an optimistic appraisal of Germany's prospects in Sea Lion, read Robert Forczyk's We March Against England. But even with all of his optimistic assumptions, he still concludes that any invasion force that made it across the Channel would have been so poorly supplied that Hitler would have had to sue for peace.

[nota]

there is only one way to invade england

it would require cooperation of all the axis nations
something perhaps very unlikely to be possible

if and only if the axis including japan send most of their fleets to support
I think there was a chance of pulling it off

[T. A. Gardner]

See post #3 here:

viewtopic.php?f=11&t=72081

This subject has been beaten to death on this an probably every other military history board in existence. I know on this very board there are very detailed threads discussing landing craft and the barge conversions the Germans planned to use as well as the same on the planning overall.

Bottom line: Germany loses if they try it.

[Barrett]

Many many thanks T.A. My searches locked up--apparently a hardware problem with the duty iMac. Your reference is excellent.
And yeah--Blumentritt seems to speak for all.

[Bob Forczyk]

That's not what I concluded at all.

I wrote that the Germans had the resources to land a significant combat force in Kent/Sussex and that the British counterattacks would fail to evict them. However, the Germans lacked the ability to get a significant mechanized force across as naval losses mounted, which meant that Sealion would likely have led to a stalemate like Anzio beachhead. At that point, both sides could keep feeding in infantry, but the British would run out of trained troops first.

I concluded that if the Germans continued an attritional battle around the beachhead throughout the winter of 1940/41, the resulting stalemate would likely lead to negotiations by spring 1941 (before the Germans could mount another amphibious assault, with better resources).

[HistoryGeek2019]

That's not what I concluded at all.

I wrote that the Germans had the resources to land a significant combat force in Kent/Sussex and that the British counterattacks would fail to evict them. However, the Germans lacked the ability to get a significant mechanized force across as naval losses mounted, which meant that Sealion would likely have led to a stalemate like Anzio beachhead. At that point, both sides could keep feeding in infantry, but the British would run out of trained troops first.

I concluded that if the Germans continued an attritional battle around the beachhead throughout the winter of 1940/41, the resulting stalemate would likely lead to negotiations by spring 1941 (before the Germans could mount another amphibious assault, with better resources).

Hello Mr. Forczyk! I just want to say, I loved your book about Operation Sea Lion. Sorry for misrepresenting what you wrote. It's true that you wrote that both sides would have faced serious attritional issues that would have impelled both to seek a peace. I just interjected my own view that the British could have have weathered such attrition better than the Germans. I believe the ancient Romans had a principle that they would never negotiate with a foreign power while it had troops on Roman soil - I believe Britain would have followed the same principle and refused to negotiate with the Nazis which, would have meant doom for the German invasion force.

[Bob Forczyk]

Doom from what? Leprosy??

While Churchill would certainly have opposed negotiation, the Germans could sustain several infantry divisions along the coast for some time with a combination of night air drops and fast merchant vessels. An infantry division on the defense, in static positions, could make do with as little as 40 tons of supply, perhaps a bit less if they were sparing on artillery.

The British Army had no trained infantry reserves in 1940 and would consume troops as fast as they could train them to head off to the beachhead. Churchill would be screaming for assaults, meaning that many novice troops would be sacrificed against dug-in German veterans. It's not a scenario that plays out well for the British. Brooke would be forced to use virtually all his good divisions to surround the German beachhead, leaving negligible reserves.

Keep in mind that the US would be much less likely to pass Lend Lease if the British could not crush the German beachhead. Without LL, the British war effort in 1941-42 would have been much degraded. Furthermore, a protracted struggle in Kent/Sussex means no reinforcements for the 8th Army in Egypt .

[HistoryGeek2019]

Doom from what? Leprosy??

While Churchill would certainly have opposed negotiation, the Germans could sustain several infantry divisions along the coast for some time with a combination of night air drops and fast merchant vessels. An infantry division on the defense, in static positions, could make do with as little as 40 tons of supply, perhaps a bit less if they were sparing on artillery.

The British Army had no trained infantry reserves in 1940 and would consume troops as fast as they could train them to head off to the beachhead. Churchill would be screaming for assaults, meaning that many novice troops would be sacrificed against dug-in German veterans. It's not a scenario that plays out well for the British. Brooke would be forced to use virtually all his good divisions to surround the German beachhead, leaving negligible reserves.

Keep in mind that the US would be much less likely to pass Lend Lease if the British could not crush the German beachhead. Without LL, the British war effort in 1941-42 would have been much degraded. Furthermore, a protracted struggle in Kent/Sussex means no reinforcements for the 8th Army in Egypt .

In Chapter 7, you write:

[Hitler] would likely be running out of shipping after a few months of this and then his armies in England would become less and less capable. Given the resources of 1940, he would never get a large Panzer force across the Channel to capture London. Instead, his armies and fleets would bleed to hold onto obscure British towns, hoping for an armistice that became increasingly unlikely.

Forczyk, Robert. We March Against England (p. 262). Bloomsbury Publishing. Kindle Edition.

You then go on to suggest that Churchill would order a large offensive to retake Dover, which would probably fail. But why would Churchill order a large offensive if Germany is running out of transports? Churchill may have been rash, but he wasn't stupid. He did approve of the GHQ line, after all, which was a defensive, interior strategy designed to allow the Germans to land on the beaches and then whither away from lack of supply. He approved of the BEF withdrawing from France instead of attacking. He approved of withholding fighters from the Battle of France. He approved of withdrawing from Greece in 1941. These are all rational, defensive measures that take account of Great Britain's overall strategic situation: it is a naval power, and its success in any war depends upon its navy. If Germany is running out of transports, Britain will continue to focus on destroying Germany's transports.

You yourself write that Germany had only "modest" anti-submarine measures. British submarines would have been patrolling the Channel every night. Britain was vastly outproducing Germany in ships. Britain could replace its naval losses. Germany could not.

I also think you mischaracterize the political situation. The British people hated the Germans. They would have hated them a hundred times more if Germany dared to land on British soil. Britain was outproducing Germany in ships and aircraft while devoting a smaller proportion of its GDP to the war than Germany. If German troops landed on British soil, the British people would have responded with overwhelming zeal and patriotism to destroy the invaders. Likewise, anti-German sentiment in the United States would have swelled even further. Lend-lease probably would have been approved within days of any German landing. American volunteers (along with tanks, planes, artillery and ammunition) would have been pouring into Britain. There is no way on God's green Earth that Churchill or any British prime minister would make a negotiated settlement with Germany because of a few stranded German divisions on British soil.

[Max Payload]

An infantry division on the defense, in static positions, could make do with as little as 40 tons of supply, perhaps a bit less if they were sparing on artillery.

I’m not sure where you get the 40t figure from. That works out at little more than 2kg/p/d. Infantry involved in heavy defensive fighting would require around ten times that.

Sealion would likely have led to a stalemate like Anzio beachhead. At that point, both sides could keep feeding in infantry, but the British would run out of trained troops first.

Not having read your book I can only comment that that is a decidedly minority view. And even if the British were to run low on trained troops, there would have been no lack of untrained volunteers, and millions of hacked-off guys armed with little more than pitchforks could, if committed en masse, have seen off two or three inadequately supplied enemy divisions.

[Barrett]

Ref. British equipment. Dunkirk of course deprived the Brits of thousands of tons of supplies and ammo plus thousands of vehicles. But IIRC by August there had been some redress although a table of organization (that I cannot find now) indicated a shortage of MGs and mortars and probably arty.

In 1981 I visited the Hendon museum complex (had a wonderful 1 on 1 with Douglas Bader who was selling books) and noted a rack of pikes along one wall. They were iron, bearing the royal seal and the date 1940....

Meanwhile, there was a US umbrella organization called "Committee for Defense of British Homes" which coordinated private program such as the NRA s to send weapons, ammo and accessories to the UK. That was separate from US Govt work, and continued through 1941, IIRC.

Just FWIW.