Was Sea Lion possible?

[Swinds]

IMHO it was impossible IRL... for these reasons. I know of at least one member of the forum that disagrees what do you think?


Just to show a proper historian also believe what I have tried to explain below...

http://ww2history.com/experts/Andrew_Roberts/Existence_of_a_real_German_threat

axis history forum...

https://forum.axishistory.com/viewtopic.php?t=38244

Military History Online

http://www.militaryhistoryonline.com/wwii/articles/sealionvsoverlord.aspx


My points...

1. The RAF bomber force was not hit within the BoB battle. Nether was Coastal Command (but I assume that they would not have been able to do much)

2. GB positioned Cruisers and Destroyers within striking distance and one R-Class Battleship in Plymouth.

3. Mines, there were a lot of mines in the channel that were not know to the German navy therefore before the invasion fleet could progress over the channel they would have to sweep ahead to clear them. This would have increased the journey time.

4. Currents in the Channel are very strong and the top speed of the powered barges was 5 kts in good sea conditions.

5. I have seen quoted that it would have taken 24hr to cross the channel at the shortest point with tides and barge speed taken into account. I am not a sailor so I can't confirm this.

6. The Barges were put all along the channel coast and that increase crossing times and distances quite a bit.

7. GB was on a very high alert and were looking for signs that the invasion was starting. It looks on paper that the invasion fleet would have had to start leaving in daylight the previous day. So easy to see with aircraft flying over the channel.

8. A night action was better for the RN than a day action because of the Luftwaffe, for reasons you have highlighted. As it happens the invasion fleet would have been in the channel all night.

9. GB knew hitting the invasion fleet and particularly the irreplaceable barges would mean Germany could not invade again till it have build replacement ships. Therefore loosing a large part of the bomber force and a large amount of warships would not be as bad as loosing the barges for the German navy.If GB could put off an invasion to 1941 and at the same time destroy German divisions of experienced men they would be in a much stronger position the following year. Think the RAF in April 1941 against September 1940. Germany would again have to get air superiority. So whatever the cost the invasion would need to be stopped and GB could not beat Germany in a land battle. Given a choice between sacrificing part of the air force and navy against a German occupation... There is no need for Aircraft after an occupation.

10. The German Navy never thought it was possible, there are many quotes from Raeder around.

11. Air Superiority, Even though GB were losing the BoB up to the switch attacking London because of the pilot shortage. The Luftwaffe were not in a good state either and could not take the rate of attrition need to finish the job. The amount of fighters available to Fighter Command had not dropped sufficiently for this to be realistic in the time frame or within the resources of the Luftwaffe.

12. Every, and I mean every aircraft available to the RAF including Hawker Hendley with poison gas tanks !! would have hit the beaches and the ships the morning of the invasion. Even with air superiority some would have got through. Think Dunkirk.


Quote, I would need to go over my books on this but it looks likely....
Bomber Command 16 June 1940

No 2 Group West Raynham(18,101), Wattisham (107,110), Bodney (21) Watton (82) Wyton (40,57), Alconbury (15), Horsham St Faith (114,139). 11 squadrons, all equiped with Blenheim IV, but only 6 squadrons declared operational.

No 3 Group Feltwell(37,75NZ)Newmarket (99) Mildenhall (149)Stradishall (214), Marham (38,115) Honington (9). Total 8 squadrons, 7 operational. Equiped with the Wellington 1A, 1C.

No 4 Group Dishforth (51), Linton on Ouse (58) Topcliffe (10), Driffield (77) Cottam (102), York (78). 6 squadrons, 5 operational. Equiped with Whitley IV, IVA, V.

No 5 Group Hemswell (61,144) Scampton (49,83) Waddington (44,50), Finningley (106) 7 Squadrons, 6 operational. Equiped with Hampdon aircraft.

No 1 group was the battle group - and was detached to be part of the Advanced Air Striking Force. I dont have its strength at this point, but at the start of the war it had 10 operational squadrons of Battles.

Overall, excluding detached forces, Bomber command had 32 squadrons in June 1940, of which 8 were not yet operational. Of course total aircraft numbers will be much larger, and included types involved in advanced training and conversion, and would include other and subsequently obsolete types.

 

[Sleight of Hand]

Absolutely not, no. Look at what a disaster Weserübung was for the Kriegsmarine, and they met only minor resistance from a much weaker combatant than Great Britain.

It is my understanding that Germany didn't even have the necessary troop ships and landing craft to move sizable troop numbers across the Channel, and they certainly didn't have anywhere near the surface fleet required to destroy the bulk of the Royal Navy -- which would have been a necessary precursor to a cross-Channel invasion.

As soon as the British knew that an invasion was being planned they would have thrown all of their air and naval assets at it, including bringing back most or all of their capital ships from other theaters. Just look at the determination and resources allocated to sink the Bismark, a single modern battleship; it would have been that response ten-fold had the RAF spotted a staging ground being used for invasion.

Also, it would have required the Luftwaffe to have won the Battle of Britain, which they obviously didn't. Without air supremacy, everything else falls apart.

So, historically and realistically, it's not really plausible at all. Germany simply did not invest anywhere near enough in its surface fleet, and after the Battle of Britain the Luftwaffe began to suffer as well.

For Seelöwe to succeed you have to assume a number of factors which Germany was logistically unable to attain: naval supremacy, air supremacy, a working supply line, and much more. None of this was in place and the window to achieve it was extremely limited; once the United States joined the war on Great Britain's side then it immediately becomes moot.

 

[Swinds]

I suppose I should have said in September/October 1940

 

[Gratch11]

It would definetely have been a gamble, but maybee one worth taking at the fall of France

Reasons

1/ All heavy UK equipment were at Dunkirk
2/ Landings would have been close to fighter cover
3/ UK sub hunting capacity wasnt very good at this time

I think that if Germnay had known the fallout from case yellow they might have been more prepared about what to do after the fall of france, now they were just happy and didnt start to plan until after france fell. An invasion would have to take place early july at the latest.

I wish to point out that it hard to fault not going through with it, but in hindsight I think it would have been worth it.

 

[Kovax]

Not possible without a lot of advanced preparation, which was not done. Even if Germany had managed to effectively cripple the RAF, that would still have left Germany without enough aircraft to make the Channel a no-go zone for the RN. The river barges and small fishing vessels available were marginally adequate at best for ferrying troops over in a completely unopposed landing against a minor country with little warning, but basically incapable of launching an amphibious invasion of a major power that's expecting it.

 

[Big Nev]

I’ve had numerous discussions on the feasibility of Sealion and, in 1940, it was, quite frankly, a joke.

I’ve found a link to a paper by one Alison Brooks that pretty-much spells it all out.

I particularly like this bit.

“The barges were mainly those designed for use on the Rhine, with a shallow freeboard. They sink in anything above Sea State 2. The wash from a fast-moving destroyer would swamp and sink the barge. (Correct: the RN could sink the lot without firing a shot).”

Something I’ve been saying for a long time but nobody seems to want to listen.

Enjoy the read. It’s quite entertaining in places.

http://www.philmasters.org.uk/SF/Sealion.htm#Plan




Sadly, she’s no longer with us.

 

[Swinds]

Something I’ve been saying for a long time but nobody seems to want to listen.

I do I got a very strange email reply from a gentleman who did not agree with my points. I had read before about the barges being trouble in sea states above 2.

 

[CV10]

In order to launch an amphibious assault and then support it, it seems a given that you will need sustained naval support at some point. I don't think that it was ever possible for the Kriegsmarine to support an amphibious landing on the British Isles. Can anyone name an anmphbious assault where the attacker was successful, and did not have sustained naval support?

 

[elpibeuruguayo]

No.

 

[seattle]

2 considerations:

1. Historical June 1940. Germany isn't prepared at all.
The air campaign proved somewhat effective until Goering switched to strategic bombing. There are many people (incl. Brits) who saw the British defences close to a collapse before that. The air fields, radar stations and overall interceptor force were badly battered. Had Goering continued to target them, Sealion would at least have been a bit more viable. I doubt that it would have been possible though.

2. Germany prepares for Sealion from 1938 onwards.
Specialized landing craft instead of the non-existing transport fleet. More long-range fighters, more tac bombers, etc.
Had Germany known that in summer of 1940 there would be a short time window for Sealion and properly prepared for that, then Sealion could have succeeded.
However, there's zero plausible reason how Germany would have known that. Nobody would have expected a French defeat within 6 weeks!
-----------------

Realistically Germany could have done better in not switching to strategic bombardment and instead continue the focus on British defences. That would have given Sealion a minimal chance, but not more.

 

[LTPugh]

I’ve had numerous discussions on the feasibility of Sealion and, in 1940, it was, quite frankly, a joke.

I’ve found a link to a paper by one Alison Brooks that pretty-much spells it all out.

I particularly like this bit.

“The barges were mainly those designed for use on the Rhine, with a shallow freeboard. They sink in anything above Sea State 2. The wash from a fast-moving destroyer would swamp and sink the barge. (Correct: the RN could sink the lot without firing a shot).”

Something I’ve been saying for a long time but nobody seems to want to listen.

Enjoy the read. It’s quite entertaining in places.

http://www.philmasters.org.uk/SF/Sealion.htm#Plan




Sadly, she’s no longer with us.

Sad to hear the author is no longer with us, but I've saved that link specifically for any time somebody tries to argue for Sealion again.

Thanks, it was a great read.

 

[Denkt]

I would say no, Germany could not do a successful invasion of UK.

Germany did not have the ability to claim air superiority over UK. Neither could the claim naval superiority. Yes they could try to sink UK ships with naval bombers however UK anti aircraft guns was in a complete different league (lack of good aa seems to have been a huge weakness of the major axis power) and german aircrafts can not protect their ships well enough close to UK coast.

Germany would have problems with the needed fuel for such invasion.

It is even doubtful that Germany could pull of a successful invasion of Sweden.

 

[Director]

Turn it around and look at the difficulties the Allies faced getting just 6 divisions ashore on D-Day. Admittedly, Britain did not have the kind of defenses that the Germans had built in France.

But neither did Germany have the sort of air domination the Allies relied on in Normandy, nor did they possess the sort of sea-power the Royal Navy could bring to bear. It would be better if the Germans tried to cross at night - the RN's night-fighting ability was very good and their light forces (cruisers and destroyers) were superb.

If Germany planned on SeaLion from 1933 on, and built the necessary naval forces including proper landing craft, and Britain did not react by building any new naval assets at all, and Germany built the Luftwaffe with SeaLion in mind, and Britain didn't build up fighter command or the radar system, and the BEF was overrun and taken at Dunkirk, and the Royal Navy gets blown apart by the Luftwaffe, then... then we're in some fan-boy wank-fest that bears no reality to any history I consider plausible.

Why don't we just imagine the Germans sink concrete barriers and drain the Channel? Or develop zeppelin-powered bridge sections for a Channel-spanning autobahn?

 

[Secret Master]

I was excited, because I thought we were going to discuss situations in which Sea Lion might have been possible.

But a historical 1940 with historical equipment and OOB after the fall of France? Nope, not even a slim chance of success.

 

[Secret Master]

If Germany planned on SeaLion from 1933 on, and built the necessary naval forces including proper landing craft, and Britain did not react by building any new naval assets at all, and Germany built the Luftwaffe with SeaLion in mind, and Britain didn't build up fighter command or the radar system, and the BEF was overrun and taken at Dunkirk, and the Royal Navy gets blown apart by the Luftwaffe, then... then we're in some fan-boy wank-fest that bears no reality to any history I consider plausible.

 

[Director]

Sorry - I got up cranky this morning. Couldn't get to sleep at a reasonable hour, woke at 3:30am on 4 hours sleep, drank coffee. Had to drive to Washington, DC - a 2 hour drive turned to 3 by rush-hour traffic and rain.

Get to the theater, drink a large iced-tea, ready to solve the mystery of why their auditorium signs don't work. Find the problem is a Cat-5 cable not fully pushed into the connector. With that done, all the signs light up properly.

Get a Coke. Still raining. Heavy traffic on I-95; drive 2 1/2 hours home. Consider detouring through Gettysburg but it is still raining. Caffeine headache and extreme fatigue. Arrive home grumpy, find another post about SeaLion (no offense, Swinds - you're always an intelligent poster) and the bomb goes off. So - apologies if needed.

But... autobahn-sized 4-lane bridge spans the Channel held up by a fleet of zeppelins? Now THAT's an image... "I do not say they cannot come, I only say they cannot come by sea..."

Secret Master -- the secret master of snark.


I'd say the best chance would have come if Germany had trapped the BEF (and any French troops at Dunkirk), then mounted the world's biggest para-and-glider drop. Supposedly Student (I think) recommended using paras to knock out British fighter command bases and radar but Goering wouldn't buy it. Before the RAF is crippled, you'd still need the Germans to lay extensive minefields, and you'd need them to start producing decent landing craft in, maybe, 1936 or so. Even so, you have a fair chance of losing your paratroop/glider forces and not getting across the Channel. But... maybe a decent shot at pulling it off, call it - what - 25%?

Okay, Secret Master - what's YOUR plan for a SeaLion victory?

 

[keynes2.0]

Why don't we just imagine the Germans sink concrete barriers and drain the Channel?

That's crazy. What they should have done is build a tunnel, that way the RAF and RN would be helpless. Obvious, really.

 

[Fulmen]

Without the intention of too much derailing the thread, I wish to ask another kind of question. What if Hitler had not halted Guderian's Panzers, what if the BEF had been captured? Would England have accepted Hitler's calls for peace?

Opinions, reasonings?

 

[keynes2.0]

If Hitler hadn't "halted" the panzers then the forward elements would have engaged in low level skirmishing for an extra two days before substantial forces arrive and the Germans actually have enough forces to make a real attack.

 

[Axe99]

Haha, Director's on the rampage . IRL, I don't think there was any chance Germany could pull it off without some exceptionally lucky results, but I think it'll likely be more possible in-game. Like HoI's past, I expect successful invasions will require a lot less specialised invasion craft than they did historically, and that Germany'll get a bit of a buff to help it out. With that, and if the AI is a bit silly, there might be a chance.