Operation Sealion

Discussion in 'NW Europe' started by spidge, Dec 13, 2005.

  1. spidge


    From numbers that I have read, the Army wantd to invade with 16 Divisions however the numbers below seem to be the settled number if the invasion was to go ahead.

    It is said that Hitler was prepared to offer Britain generous peace terms. Hitler had planned an economic war which could have taken a long time to be effective. However, a military conquest of Britain would be swift and decisive. The military success of the German military since September 1939, seem to confirm in Hitler’s mind that an attack on a demoralised British Army would be swift.

    To be successful, the German machine needed:

    Control of the Channel, Control of the skies & Good weather

    What did Britain have to throw against these landings if the navy had not been able to destroy the landing forces en route?

    The projected invasion on Britain included:

    Army Group A (6 divisions) invading Kent via the areas near Ramsgate, Folkstone and Bexhill

    Army Group A (4 divisions) invading Sussex and Hampshire via the area around Brighton and the Isle of Wight.

    Army Group B (3 divisions) invading Dorset via Lyme Bay

    From Kent, Army Group A would advance to south-east London and then to Malden and St. Albans north of London.

    From Sussex/Hampshire, the 4 divisions of Army Group A would advance to the west of London and meet up with the other 6 divisions of Army Group A, thus encircling London. Other parts of the group would head towards Gloucester and the River Severn region.

    From Dorset, Army Group B would advance to Bristol.

    Operation Sealion looked simple in theory. Britain should have been an easy target.
    The RAF and the Army in Britain looked weak; only the Royal Navy seemed to offer Britain some semblance of protection.

    What in essence could they have done?

    There were plans on paper - What did they entail?
    James S likes this.
  2. jamesicus

    jamesicus Senior Member

    I haven't any primary source research to offer in support of the following assertion, Spidge, but my opinion is that there weren't very many battle-ready regular British army resources available -- but there were some. For example, the 52 (L) Division which escaped from France via Cherbourg intact, with virtually all their equipment, returned to England where they were re-formed and re-equipped at Kennet in the south-midlands:

    Unit Christmas card

    I am sure there were others major units.

    And anecdotally -- some who were evacuated from Dunkirk were temporarily garrisoned at the Old Trafford (Manchester) Lancashire County Cricket ground which was one of the designated facilities for processing Dunkirk survivors and retraining them into re-formed army units.
  3. spidge


    Very good card. Pictures sure tell the story.

    What were the naval gun implacements like around Britain? I know about the pill boxes etc however I have not seen a detailed description of the number or locations.

    Does anybody have this type of info?
  4. jamesicus

    jamesicus Senior Member

    miss-post, sorry
  5. angie999

    angie999 Very Senior Member

    I do not think that there was ever any serious German intent to carry out Sealion. For one thing, I do not think they had the lift capacity to support an amphibious assault of this size. For another, the naval chiefs did not consider it achievable.
  6. mattgibbs

    mattgibbs Senior Member

    Weren't most of their invasion troop carrying barges flat bottomed, not so good in the Channel one would think?
  7. angie999

    angie999 Very Senior Member

    Yes. A lot of them were comverted unpowered river barges. They would have had to be towed. Not exactly landing craft.
  8. jimbotosome

    jimbotosome Discharged

    But could they not have remedied this quickly? Had they have used their bomber forces to protect the channel and the landing grounds then might this not have succeeded? I just don't think LCT and LCS's were really that hard to develop for an industry like Germany's. Look how fast the US produced Liberty ships. They were far more complex than what would be needed to cross the channel. They could have come up with their own version of Higgins boats.

    I question whether the RN could have defended the Channel. It would just be too vulnerable to mines, aircraft, shore batteries and submarine patrols. All the submarines would have to do is fire and move closer to the shores of France where Destroyers could not pursue.

    I think the thing that stopped Sea Lion was the fact that the Germans didn’t realize that radar was killing them. Radar made the RAF as effective as a much larger air force. Had the Germans have realized it they could have saved themselves a lot of downed aircraft. Radar was so crude then that it could be easily attacked as it used huge antenna arrays.
  9. angie999

    angie999 Very Senior Member

    It took the allies until 1944 to develop a force of such ships which was still not really enough for Overlord. It is not something the Germans could have done in time for an invasion in 1940, the only year when the comments about Britain's lack of defences could be applied.

    Plus, not only did they lack experience, they had not really studied amphibious operations in any detail either.
    Last edited by a moderator: Oct 26, 2018
  10. mattgibbs

    mattgibbs Senior Member

    The Luftwaffe did attack the antenna arrays, they did guess their purpose. They had radar as well. They just used longer frequencies and did not appreciate how low a frequency we were using. Their famous [?] coastal sortie pre war with the Graf Zeppelin hung with radar detection gear proved that. They couldn't see our radar but we tracked them along the east coast although they were well out of visual range.

    How long do you think ot would have taken for them to manufacture Higgins type boats for the amount of men they were planning to ship in the initial phases.

    Royal Navy Warship Strength

    The Royal Navy, still the largest in the world in September 1939, includes:

    15 Battleships & battlecruisers, of which only two are post-World War 1. Five 'King George V' class battleships are building.

    7 Aircraft carriers. One is new and five of the planned six fleet carriers are under construction. There are no escort carriers.

    66 Cruisers, mainly post-World War 1 with some older ships converted for AA duties. Including cruiser-minelayers, 23 new ones have been laid down.

    184 Destroyers of all types. Over half are modern, with 15 of the old 'V' and 'W' classes modified as escorts. Under construction or on order are 32 fleet destroyers and 20 escort types of the 'Hunt' class.

    60 Submarines, mainly modern with nine building.

    45 escort and patrol vessels with nine building, and the first 56 'Flower' class corvettes on order to add to the converted 'V' and 'W's' and 'Hunts'. However, there are few fast, long-endurance convoy escorts.

    As to how many would have been available against Sealion in 1940, any ideas? I think the Royal navy would have had a good crack at defending the Channel.

    Is it likely that in the event of invasion the RAF would have switched, once the German fleet was detected, to bombing of airfields in France etc to disrupt air support for the invasion?

  11. Gnomey

    Gnomey World Travelling Doctor

    If an invasion attempt had been launched then the Royal Navy would have been launched (in full) against it as well as Bomber Command. The RN could have severely disrupted the invasion fleet without firing a shot as the wake off a fast moving ship would of upset and sunk the majority of the barges the Germans were using as "Landing Craft". Another point was that the landing craft were not suited to open water sailing unless the water had been flat calm and the English Channel in late Autumn is rarely flat calm. All in the Germans plans were flawed, I did read a website that detailed all the problems with the German invasion attempt and why it would of failed, however I can't find it at the moment.

    All in all I believe that Britain was very defendable when facing what the Germans had to throw at them. If the Germans had got ashore the resupply and logistics required by a sea borne invasion force was inadequate and would of left the troops on the beaches under-supplied. In the end the final outcome isn't really in doubt for me, it is just a question of how far the Germans get before being forced back. As it stands they didn't even set off.

    EDIT: Here is (I think) the site a mentioned: http://www.flin.demon.co.uk/althist/seal1.htm
  12. jamesicus

    jamesicus Senior Member

    British miltary planners were concerned about the possibility of German airborne operations (paratroops and gliders) in support of an invasion force. The Government took various protective measures against this eventuality: series of inclined girders were sunk in the ground at large, flat, even areas such as playing fields and parks and we couldn't use those facilities for about a year; The Home Guard (at least in my area) posted round-the-clock guards at these places and conducted continuous anti-airborne exercises. Here is a page from my father's Home Guard training manual that I still have:


    Of course, schoolboys like me found all this preparation very exciting and adventurous. I was in training to become an ARP messenger and I got to role-play an enemy soldier during my father's Home Guard exercises!
  13. Tonym

    Tonym WW2 Veteran WW2 Veteran

    The impression that I get from the original questioners comments is that we were all quivering with fear at the prospect of a German invasion after Dunkirk. Far from it, concerned proberbly, but the British character was, and hopefully still is, a bit more resourceful than the precise German Military Machine. After all who brought all those troops back from the beaches of Dunkirk, a fair number of militarily untrained civilians had a bit of a hand in it and a few thousand other civilians did not buckle under the bombings of London, Coventry, Liverpool, etc.. He might have gained a foothold but life would not have been easy for him I am convinced that the British Resistance would have prevailed. The Romans gave up only the Normans succeeded but then we are their descendents. Keep in mind also that Hitler was looking over his shoulder towards the Russians at his rear. Sorry, but I am still convinced that we may have struggled for a bit but still would have won. I was there and knew how my colleagues felt.
  14. Kiwiwriter

    Kiwiwriter Very Senior Member

    I read that "Sea Lion" was "planned, but never contemplated." The Army regarded it as a large river-crossing, and made demands on the Navy and Luftwaffe for transport and cover that neither could meet.

    The plans included French- and Dutch-manned tugs shoving tied columns of unpowered barges into position to the far shore, landing horses in the first wave, and the quick seizure of intact ports to supply the troops.

    During an exercise, Jodl asked Cdr. Friedrich Ruge what he thought of "Sea Lion." Ruge answered, "Well, as we will be traveling at a slower pace than Julius Caesar's armada, I don't think much of it!"

    At some levels, it was a gigantic bluff, to overawe the British into surrender. But had the RAF been beaten, had the Churchill government never been formed (or fallen), it might have happened, and might have worked.

    Norman Longmate's "If Britain Had Fallen" and Kenneth Macksey's "Invasion" both cover how it could have happened. A fictional version is Len Deighton's "SS-GB," in which a Scotland Yard detective in occupied Britain, solving a murder, finds himself enmeshed in saving King George VI and atomic bomb research secrets. Deighton's view is that the occupation of Britain would have been like the occupation of France -- most people just trying to get along or collaborate. Interesting reading, but I disagree with his thesis.
  15. smc66

    smc66 Member

    Remember the Germans regularly buttered up Edward VIII and his wife to the extent that the Churchill government sent him to the Bahamas to get him out of the way. There were a number of appeasers and people like Lloyd George who could have taken on the Petain role.
  16. jimbotosome

    jimbotosome Discharged

    Well, the Germans thought that the RAF was much larger than it was because Fighter Command used radar effectively to coordinated intercepts. If the Germans had taken out radar as you imply then it would have never been discussed as being significant in the BofB. Initially at least the Germans were not aware of how effectively the RAF seemed to intercept their bombers. Radar stations were rebuilt quickly. Not to mention the "de-emphasis" on bombing the radar and airfields to bomb civilian targets.

    As far as your Higgins boat construction, I would think they could have had a sufficiently large fleet of them in about three months.

    There is no doubt the Royal Navy was a formidable Navy. It's only true rival would have been the US Navy and they were allies. The problem is not the quality of the Navy but the obsolescence of a Navy operating near land occupied by a capable enemy air. Ships could not have operated safely in the Channel, there are way too many threats from land sea and air. Taranto and Pearl Harbor should illustrate the dangers of being in range of air attacks. The Royal Oak and the Repulse should indicate how dangerous it would be to around subs which could concentrate in a narrow waterway like the Channel defended by shore batteries and artillery. Don't forget what happened when the Higgins boats were practicing for the invasion. The Channel can be a very dangerous place.

    At the start of Sea Lion, the Germans had a slight qualitative advantage over the RAF but had a tremendous quantitative advantage. If the RAF had had to come out over the Channel, they would lose their advantage of AAA protection and short sorties as well as the fact that pilots would be lost when shot down. These were advantages they had in the BofB. As far as warships, the Germans had a significant advantage in subs. The RN would have to have screened the area not the Channel. If they had focused on the Channel, not only would they have reduced their effectiveness in losing many ships but then the German pocket battleships could have come in close to Britain and shelled it mercilessly including the factories in the north.

    This is not a knock on the RN or the RAF but Germany was simply more prepared for a war and they were not receiving attacks on their homeland as Britain was. That makes a tremendous difference. Britain like the other allied nations was not prepared for war nor did they have any desire to fight. They fought because they had to not because they wanted to. Germany on the other hand could have taken out a lot of nations. Hitler’s greed was its only weakness.

    In 1941, Britain was simply not a priority to the Germans. They wanted Russia. Hitler should have known, just chasing them back to their island was not the end of the story. He grossly underestimated their resolve. I think after the ease of success of Dunkirk the Germans had lost respect for Britain’s ability to fight. I think that they thought Britain would capitulate like France did. Perhaps their view of the British was from their dealings with Neville Chamberlain. They should have focused their entire forces on taking Britain, it was far more than a thorn in the side.
  17. Kiwiwriter

    Kiwiwriter Very Senior Member

    That is so...Halifax, JFC Fuller, Nevile Henderson, and other lights of the British power elite admired how the Nazis had restored German pride, industry, and power, while standing up to Bolshevism and stamping down on the Jews. Longmate believes that Fuller would likely have been appointed as an acting Prime Minister to negotiate with the Nazis, had they invaded England -- his chapters on a successful "Sea Lion" end with Churchill dead at his machine-gun on Whitehall and Fuller occupying 10 Downing Street, awaiting the German emissaries.

    The Duke and Duchess of Windsor were anti-Semitic -- the Duchess openly refused to dine with Jews -- and Robert Harris has them as King and Queen of England in 1964 in his novel "Fatherland." Oddly enough, the Windsors loved New York, and spent a lot of time there, staying at the Waldorf, and shopping for clothes.

    The Duke shaved and dressed for dinner every single night until his final illness, even when there was nobody dining with him but the Duchess, which amazes me...I compare that with the relative informality of Princes William and Harry.

    My point in mentioning that is that if the Duke and Duchess did a lot of clothes-buying in New York, then they had to interact with a goodly number of Jews...I suspect it only reinforced their prejudices, though. o_O
  18. spidge


    Good site Gnomey.

    I had been looking for something like that.

    The ship tally here is quite different to that posted by Colonel Gubbins.
  19. redcoat

    redcoat Senior Member

    The first specially developed German landing craft design the Marinefährprahm, didn't start to enter service until 1941.
  20. redcoat

    redcoat Senior Member

    The numbers quoted by Colonel Gubbins was the total strength of the RN at the start of WW2.
    The numbers quoted by the web-site, was the number of RN warships available for the defence of Great Britain. It doesn't include RN warships on duty in the Med, and any other overseas postings.

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