# Operation "Sealion" (Invasion of England)-Would It Have Worked?
**URL:** https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124
**Category:** Great Debates
**Created:** [July 17, 2003, 12:43pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124 "2003-07-17T12:43:54Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@ralph124c](https://boards.straightdope.com/u/ralph124c)
#### Post date: [July 17, 2003, 12:43pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/1 "2003-07-17T12:43:54Z")
Unfortunately for Adolf Hitler (and very fortunately fo us),the planned invasion of England never got off the ground. My understanding was that Hitler and his general staff planned an invasion of England, to take placesoon after the fallof france. The plan was basically to bomb the crapout of England, and draw the Royal Navy out to sea (possibly by using the few surface ships that the Germans posessed). At this point, the German army would embark around 3 divisons onto barges acquired from holland. Troop landings would take place at Dover, Folkston, and possibly in east Anglia. Later, glider troops and parachute brigades would be landed in the Midlands. After brushing the feeble local resistance aside, these units wouldlinkup and march on London. At this point, they wouldn’t be faced than much more than the London police dept. and the Buckinham palace guards…so London would probably fall within a few days.
My question: given that Hitler was obsessed with the invasion of Russia, why didn’t his generals make the case for “sealion” much better? With England out of the war, Hitler wouldn’t have toworry about a two-front war-he would be free to deal with Russia.
And, after the Dunquerque disaster, I’ll bet that what remained of the BEF did not have a lot in the way of defensive weapons.
My real question: are there any good books on “SEALION”? Anybody see any german documents on how subjugated England would be ruled, and what Hitlerplanned to do with the royal family? (Was he planning to re-install the Duke of Windsor?)
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### Author:  [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)
#### Post date: [July 17, 2003, 1:14pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/2 "2003-07-17T13:14:05Z")
Not for nothing, but according to what I’ve been reading recently… I think it was in Panzer Battles, by Major General F.W. Von Mellenthin, the barges sunk a _heck_ of a lot. Sea Lion was an improvised assault, as Hitler truly believed Churchill would back off. According to him, “The High Command actually made preparations to disband a large number of divisions and important armament contracts wre cancelled.”
The air force, he says, was mainly designed to support ground attacks, and thanks to the RAF’s radar, Sea Lion never had much of a chance.
Not to mention, of course, the near total British naval superiority and the 1,733 planes lost in the Battle of Britain, mostly thanks to radar.
No, the sinking barges isn’t in this. It must have been in GURPS WWII: Weird War II, in the section on Dunkirk.
(Why, yes, I’ve been looking for cites on WWII tanks recently, for some reason. I just finished his account of Rommel’s campaign, which is Brits, so the Americans should show up shortly.)
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### Author:  [@dropzone](https://boards.straightdope.com/u/dropzone)
#### Post date: [July 17, 2003, 1:14pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/3 "2003-07-17T13:14:10Z")
1. It would have probably succeeded eventually. The British were not in any position to put up an extended resistance, having lost so much material at Dunkirk.
2. That said, I would not have wanted to be in the first wave of paratroopers. The Home Guard somehow gained a reputation for being filled with ineffectual, dottering old men but I’d just as soon not meet up with battle-hardened veterans of the Marne with shotguns and a score to settle.
3. There are strong suspicions that the Duke of Windsor was open to such a thing, aren’t there?
There was a fascinating show on PBS that I only saw part of that mixed documetary and docudrama to show what was planned in the event of a successful invasion.
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### Author:  [@Eolbo](https://boards.straightdope.com/u/Eolbo)
#### Post date: [July 17, 2003, 2:22pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/4 "2003-07-17T14:22:47Z")
This was once wargamed at Sandhurst using the original plans of each side. I am not the author of the following, its from my files but source is given as Sealion by Richard Cox. Not necessarily how it would have eventuated but interesting nonetheless.
* * *
Operation Sealion - summary of an exercise held at the
Staff College, Sandhurst in 1974.
The full text is in ‘Sealion’ by Richard Cox. The scenario
is based on the known plans of each side, plus previously
unpublished Admiralty weather records for September 1940.
Each side (played by British and German officers respectively)
was based in a command room, and the actual moves plotted
on a scale model of SE England constructed at the School
of Infantry. The panel of umpires included Adolf Galland,
Admiral Friedrich Ruge, Air Chief Marshal Sir Christopher
Foxley-Norris, Rear Admiral Edward Gueritz, General Heinz
Trettner and Major General Glyn Gilbert.
The main problem the Germans face is that are a) the
Luftwaffe has not yet won air supremacy; b) the possible
invasion dates are constrained by the weather and tides
(for a high water attack) and c) it has taken until
late September to assemble the necessary shipping.
22nd September - morning
The first wave of a planned 330,000 men hit the beaches
at dawn. Elements of 9 divisions landed between
Folkestone and Rottingdean (near Brighton).
In addition 7th FJ Div landed at Lympne to take the airfield.
The invasion fleet suffered minor losses from MTBs during
the night crossing, but the RN had already lost one
CA and three DDs sunk, with one CA and two DDs damaged,
whilst sinking three German DDs. Within hours of the landings
which overwhelmed the beach defenders, reserve formations
were despatched to Kent. Although there were 25 divisions
in the UK, only 17 were fully equipped, and only three
were based in Kent, however the defence plan relied on
the use of mobile reserves and armoured and mechanised
brigades were committed as soon as the main landings were
identified.
Meanwhile the air battle raged, the Luftwaffe flew 1200
fighter and 800 bomber sorties before 1200 hrs. The RAF
even threw in training planes hastily armed with bombs,
but the Luftwaffe were already having problems with their
short ranged Me 109s despite cramming as many as possible
into the Pas de Calais.
22nd - 23rd September
The Germans had still not captured a major port, although
they started driving for Folkestone. Shipping unloading
on the beaches suffered heavy losses from RAF bombing
raids and then further losses at their ports in France.
The U-Boats, Luftwaffe and few surface ships had lost
contact with the RN, but then a cruiser squadron with
supporting DDs entered the Channel narrows and had to
run the gauntlet of long range coastal guns, E-Boats
and 50 Stukas. Two CAs were sunk and one damaged. However
a diversionary German naval sortie from Norway was
completely destroyed and other sorties by MTBS and DDs
inflicted losses on the shipping milling about in the
Channel. German shipping losses on the first day
amounted to over 25% of their invasion fleet, especially
the barges, which proved desperately unseaworthy.
23rd Sept dawn - 1400 hrs.
The RAF had lost 237 planes out 1048 (167 fighters and
70 bombers), and the navy had suffered enough losses such
that it was keeping its BBs and CVs back, but large
forces of DDs and CAs were massing. Air recon showed a
German buildup in Cherbourg and forces were diverted to
the South West.
The German Navy were despondant about their losses,
especially as the loss of barges was seriously
dislocating domestic industry. The Army and Airforce
commanders were jubilant however, and preperations for
the transfer of the next echelon continued along with
the air transport of 22nd Div, despite Luftwaffe losses
of 165 fighters and 168 bombers. Out of only 732 fighters
and 724 bombers these were heavy losses. Both sides
overestimated losses inflicted by 50%.
The 22nd Div airlanded successfully at Lympne, although
long range artillery fire directed by a stay-behind
commando group interdicted the runways. The first British
counterattacks by 42nd Div supported by an armoured
brigade halted the German 34th Div in its drive on Hastings.
7th Panzer Div was having difficulty with extensive
anti-tank obstacles and assault teams armed with sticky
bombs etc. Meanwhile an Australian Div had retaken
Newhaven (the only German port), however the New Zealand
Div arrived at Folkestone only to be attacked in the
rear by 22nd Airlanding Div. The division fell back on
Dover having lost 35% casualties.
Sep 23rd 1400 - 1900 hrs
Throughout the day the Luftwaffe put up a maximum effort,
with 1500 fighter and 460 bomber sorties, but the RAF
persisted in attacks on shipping and airfields. Much of
this effort was directed for ground support and air
resupply, despite Adm Raeders request for more aircover
over the Channel. The Home Fleet had pulled out of air
range however, leaving the fight in the hands of 57 DDs
and 17 CAs plus MTBs. The Germans could put very little
surface strength against this. Waves of DDs and CAs
entered the Channel, and although two were sunk by U-Boats,
they sank one U-Boat in return and did not stop. The German
flotilla at Le Havre put to sea (3 DD, 14 E-Boats) and at
dusk intercepted the British, but were wiped out, losing
all their DDs and 7 E-Boats.
The Germans now had 10 divisions ashore, but in many
cases these were incomplete and waiting for their
second echelon to arrive that night. The weather
was unsuitable for the barges however, and the decision
to sail was referred up the chain of command.
23rd Sep 1900 - Sep 24th dawn
The Fuhrer Conference held at 1800 broke out into bitter
inter-service rivalry - the Army wanted their second
echelon sent, and the navy protesting that the
weather was unsuitable, and the latest naval defeat
rendered the Channel indefensible without air support.
Goring countered this by saying it could only be done
by stopped the terror bombing of London, which in turn
Hitler vetoed. The fleet was ordered to stand by.
The RAF meanwhile had lost 97 more fighters leaving only
440. The airfields of 11 Group were cratered ruins, and
once more the threat of collapse, which had receded in
early September, was looming. The Luftwaffe had lost
another 71 fighters and 142 bombers. Again both sides
overestimated losses inflicted, even after allowing for
inflated figures.
On the ground the Germans made good progress towards Dover
and towards Canterbury, however they suffered reverses
around Newhaven when the 45th Div and Australians
attacked. At 2150 Hitler decided to launch the second wave,
but only the short crossing from Calais and Dunkirk. By
the time the order reached the ports, the second wave
could not possibly arrive before dawn. The 6th and 8th
divisions at Newhaven, supplied from Le Havre, would not
be reinforced at all.
Sep 24th dawn - Sep 28th
The German fleet set sail, the weather calmed, and U-Boats,
E-Boats and fighters covered them. However at daylight 5th
destroyer flotilla found the barges still 10 miles off
the coast and tore them to shreds. The Luftwaffe in turn
committed all its remaining bombers, and the RAF responded
with 19 squadrons of fighters. The Germans disabled two
CAs and four DDs, but 65% of the barges were sunk. The
faster steamers broke away and headed for Folkestone,
but the port had been so badly damaged that they could
only unload two at a time.
The failure on the crossing meant that the German
situation became desperate. The divisions had sufficient
ammunition for 2 to 7 days more fighting, but without
extra men and equipment could not extend the bridgehead.
Hitler ordered the deployment on reserve units to Poland
and the Germans began preparations for an evacuation as
further British arracks hemmed them in tighter. Fast
steamers and car ferries were assembled for evacuation
via Rye and Folkestone. Of 90,000 troops who landed
on 22nd september, only 15,400 returned to France, the rest
were killed or captured.
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### Author:  [@Shortie](https://boards.straightdope.com/u/Shortie)
#### Post date: [July 17, 2003, 2:24pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/5 "2003-07-17T14:24:27Z")
The odds against it were very high indeed. The German military were presumably aware of this, even if Hitler wasn’t, and that is why they didn’t put too much effort into supporting it.
The short answer as to why it wouldn’t work is that it took the Allies, with near total air and naval supremacy over the Channel, years to build up the necessary forces, and D-Day wasn’t a certain success. The Germans had a better army than the British, but none of the other necessary factors.
[This](http://www.flin.demon.co.uk/althist/seal1.htm) is a longer and much more definitive answer (with a load more good stuff elsewhere on the page), or you could go to soc.history.what-if and search the archives there. It comes up a lot.
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### Author:  [@London\_Calling](https://boards.straightdope.com/u/London_Calling)
#### Post date: [July 17, 2003, 2:38pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/6 "2003-07-17T14:38:23Z")
Not quite sure of wargaming but it was very interesting, \*\* Eolbo\*\*. Thank you for posting it. I‘ve always thought it would have been _extremely_ messy and desperate and that the crossing itself and air superiority were the keys.
Ultimately, would the ill-equipped army be able to defend a port against whatever elements actually got ashore ?
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### Author:  [@yojimbo](https://boards.straightdope.com/u/yojimbo)
#### Post date: [July 17, 2003, 3:01pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/7 "2003-07-17T15:01:26Z")
> [@](#):
>
> \*Originally posted by dropzone \*
> The Home Guard somehow gained a reputation for being filled with ineffectual, dottering old men
[Dads Army](http://www.bbc.co.uk/bbc7/comedy/progpages/dadsarmy.shtml) helped a lot with this impression. IRL however they were any but defenseless old men as you point out.
I saw a documentary not so long ago about commandos who had been trained to take to the hills on invasion. They were to set up flying columns and use the “Hit them hard and fast and then get away as fast as possible” tactics that the Irish had used against them to great effect during the War of Independence. These guys old men now went through some of their training and techniques. Harder men I haven’t seen.
> [@](#):
>
> “…We shall not flag nor fail. We shall go on to the end. We shall fight in France and on the seas and oceans; we shall fight with growing confidence and growing strength in the air. We shall defend our island whatever the cost may be; we shall fight on beaches, landing grounds, in fields, in streets and on the hills. We shall never surrender and even if, which I do not for the moment believe, this island or a large part of it were subjugated and starving, then our empire beyond the seas, armed and guarded by the British Fleet, will carry on the struggle until in God’s good time the New World with all its power and might, sets forth to the liberation and rescue of the Old.”
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### Author:  [@dropzone](https://boards.straightdope.com/u/dropzone)
#### Post date: [July 17, 2003, 3:12pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/8 "2003-07-17T15:12:53Z")
Eolbo, I had no idea they had wargamed it, especially using some of the very people who would have been involved. Thanks!
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### Author:  [@spifflog](https://boards.straightdope.com/u/spifflog)
#### Post date: [July 17, 2003, 3:22pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/9 "2003-07-17T15:22:41Z")
Ralth, I think that a portion of your premise is incorrect. We need to keep in mind that Hitler never wanted to go to war with England at all. He really wanted to destroy Russia. He hoped that England would realize that its true ally was Germany, and that they would get on board and support (or at least ignore) his real war on Russia.
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### Author:  [@dropzone](https://boards.straightdope.com/u/dropzone)
#### Post date: [July 17, 2003, 3:26pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/10 "2003-07-17T15:26:27Z")
> [@](#):
>
> \*Originally posted by yojimbo \*
> **[Dads Army](http://www.bbc.co.uk/bbc7/comedy/progpages/dadsarmy.shtml) helped a lot with this impression. IRL however they were any but defenseless old men as you point out.**
That program and everything else I’ve seen that made fun of the Home Guard did those men a disservice. The ones in their late thirties and forties (hardly old but normally too old and valuable at home to be put on the front line) were vets of WWI and the older ones had beaten the Boers. The Home Guard needed a slogan like, “Remember me? I killed your father.”
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### Author:  [@London\_Calling](https://boards.straightdope.com/u/London_Calling)
#### Post date: [July 17, 2003, 3:31pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/11 "2003-07-17T15:31:23Z")
Just for interest purposes, this is one of the things that was going on around where I grew up – obviously, before I was born, but thank you for asking. Obviously, there was much else being prepared on different levels and in different ways but this is interesting:
[http://www.subbrit.org.uk/sb-sites/sites/s/shipley\_zero\_station/index.shtml](http://www.subbrit.org.uk/sb-sites/sites/s/shipley_zero_station/index.shtml)
[http://www.subbrit.org.uk/sb-sites/sites/s/stapliefield\_au\_hide/index.shtml](http://www.subbrit.org.uk/sb-sites/sites/s/stapliefield_au_hide/index.shtml)
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### Author:  [@Eolbo](https://boards.straightdope.com/u/Eolbo)
#### Post date: [July 17, 2003, 3:49pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/12 "2003-07-17T15:49:44Z")
London\_Calling, I suspect they would have struggled to capture a port and Dieppe comes to mind but even assuming they could capture one I dont know how much it would have helped. With the RAF still very much in the picture its likely the port would have been hit very hard but I think the biggest factor port or not is still the absence of any effective naval cover for the crossing. Port only helps if you’re not sunk en route.
I just checked a reference in Operation Sea Lion by Peter Fleming, which is quite an old book but still a good overview. He has some information on port capacities. The port they were most likely to initially capture was Folkestone which was calculated as being capable of receiving circa 150 tons of supplies per day initially, and rising to circa 600 tons a week later after blockships and obstacles had been removed from the harbour and British demolitions repaired. Under the reduced supply scales the landing divisions were to receive that supply capacity was sufficient for two divisions only. Assuming they also managed to take Dover which had a slightly higher rating they would after a week have a logistic capacity that would support two-fifths of their total force. For the first week it would only support _one-twentieth_ of their force.
That’s not a prospect I would relish as a commander.
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### Author:  [@Futile\_Gesture](https://boards.straightdope.com/u/Futile_Gesture)
#### Post date: [July 17, 2003, 5:41pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/13 "2003-07-17T17:41:28Z")
> [@](#):
>
> \*Originally posted by spifflog \*
> \*\*Ralth, I think that a portion of your premise is incorrect. We need to keep in mind that Hitler never wanted to go to war with England at all. He really wanted to destroy Russia. He hoped that England would realize that its true ally was Germany, and that they would get on board and support (or at least ignore) his real war on Russia. \*\*
I think Hitler may have messed up by tackling England & Russia, apparently (if you take the statements on this thread as any guide) totally oblivious to the fact he was up against the United Kingdom and the Soviet Union.
Was he using a really old map or something?
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### Author:  [@E-Sabbath](https://boards.straightdope.com/u/E-Sabbath)
#### Post date: [July 17, 2003, 6:32pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/14 "2003-07-17T18:32:46Z")
… Yes. Yes, he was. He was also a raving nutter.
A more interesting question is what would have happened to the overall war effort if he’d not ordered the Germans to stop at Dunkirk, and they’d rolled up the Brits. Would the Brits have let him keep Europe?
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### Author:  [@Quintas](https://boards.straightdope.com/u/Quintas)
#### Post date: [July 17, 2003, 8:00pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/15 "2003-07-17T20:00:28Z")
Even if the Germans had complete air superiority over the channel, I don’t think the RN would have had a difficult time blowing slow moving,overloaded barges out of the water. The infantry that did make it would have been resupplied sporadically, if at all. I believe it would have failed. I think so few would have made it to shore that the brithish police may have just arrested them 🙂
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### Author:  [@kingpengvin](https://boards.straightdope.com/u/kingpengvin)
#### Post date: [July 17, 2003, 8:04pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/16 "2003-07-17T20:04:14Z")
Probablty the same way they let Napoleon keep Europe…
In other words they would have bidded their time behind the protection of their Naval superiority (and Air superiority) and struck back when they had the sufficent forces to do so. Hey… wait a minute that is what they did… what do you know. It would have taken them longer but the plan was teh same. meanwhile the Germans would be bleeding themselves of in the Eastern front.
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### Author:  [@The\_Peyote\_Coyote](https://boards.straightdope.com/u/The_Peyote_Coyote)
#### Post date: [July 17, 2003, 8:08pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/17 "2003-07-17T20:08:00Z")
I think Operation Sealion would have failed. From what I’ve read, Hitler’s admirals were extremely dubious about the prospect, especially since the Royal Navy was still pretty strong.
It would have been a ghastly battle, regardless. William Shirer’s _The Rise and Fall of the Third Reich_ and Churchill’s memoirs give one the impression the British would have hit the Boche with everything they had, including poison gas.
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### Author:  [@Capt.Ridley\_s\_Shooting\_Party](https://boards.straightdope.com/u/Capt.Ridley_s_Shooting_Party)
#### Post date: [July 17, 2003, 8:17pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/18 "2003-07-17T20:17:36Z")
There was a program on British TV last year I think, detailing Churchill’s secret army. He had anticipated a German attempt at taking the British Isles, and so set about creating an organised underground army that would tackle any German troops if they were to invade.
They had a what must have been 80 year old veteran of this army explain a few of the tactics they were taught in the army. The presenter asked him what he would have done if a German had run at him with a bayonetted rifle, and picked up a large stick to demonstrate. The veteran grappled the stick out the mans hands and threw him to the floor. He then said “at this point, I’d beat you to death with the end of the rifle, as a bullet firing in the night would be very conspicuous”, or words to that effect.
People tend to underestimate what had been organised in case of an invasion, and many people at the time, IIRC, accused members of this underground army of being cowards, without actually knowing that if there was an invasion, they’d be the first to die 😑
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### Author:  [@dropzone](https://boards.straightdope.com/u/dropzone)
#### Post date: [July 17, 2003, 8:57pm UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/19 "2003-07-17T20:57:06Z")
Jeeze, the poor bastards in the slow, easily swamped barges would even been sitting ducks to high altitude medium and heavy bombers. “Load up the Wimpy, boys; we’re going to shoot fish in a barrel!” Even without total air superiority flying in from outside the range of the German fighters, dropping your bombs, and flying back out of range would put you in harm’s way for a much shorter time than a daylight raid on France or Holland.
Maybe I should revise my earlier “It would have probably succeeded eventually.”
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### Author:  [@London\_Calling](https://boards.straightdope.com/u/London_Calling)
#### Post date: [July 18, 2003, 1:26am UTC](https://boards.straightdope.com/t/operation-sealion-invasion-of-england-would-it-have-worked/189124/20 "2003-07-18T01:26:05Z")
\*\* Eolbo\*\* - The consensus seems to agree with you on the probability of the Germans not getting enough ashore to take and hold a port.
In general:
The comprehensive page **Shortie** links to has a lot of (perhaps biased) information and is rather interesting. It concludes with another reference to wargaming by the bods at Sandhurst:
“We can choose to wave a magic wand, and wipe out the RN and the RAF, and examine how successful the invasion was likely to be in their absence. Sandhurst has done this on four occasions to my knowledge. Both sides were given the historical starting positions, with an invasion date of 24 September.
In each case, the details of the fighting varied, but by each analysis resulted in 27 September dawning with the Wehrmacht holding two isolated beachheads, one at roughly 2 divisions strength on Romney March, and one of 1 division at Pevensey. Each were opposed by more numerous forces, with growing numbers of tanks and artillery. German resupply was still across open beaches. “
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