Operation Sealion

[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?

[jamesicus]

(spidge @ Dec 13 2005, 05:52 AM) Quoted post</div><div class='quotemain'>..... What did Britain have to throw against these landings if the navy had not been able to destroy the landing forces en route? .....[/b]

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 -- two of my cousins 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.

[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?

[jamesicus]

miss-post, sorry

[angie999]

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.

[mattgibbs]

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

[angie999]

(Colonel Gubbins @ Dec 13 2005, 01:50 PM) [post=43071]Weren't most of their invasion troop carrying barges flat bottomed, not so good in the Channel one would think?
Regards
MG
[/b]

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

[jimbotosome]

(angie999 @ Dec 13 2005, 09:06 AM) [post=43073]

Yes. A lot of them were comverted unpowered river barges. They would have had to be towed. Not exactly landing craft.
[/b]

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.

[angie999]

(jimbotosome @ Dec 13 2005, 02:28 PM) [post=43077]

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.

[/b]

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.

[mattgibbs]

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?

Regards
MG