Invasion England - Threat Assessment (1940!)

[Goatman]

You know how it is.....pop on the web to check yr email and next thing you know you're hip-deep in contemporary accounts of Operation SEELOWE....

came across this - thought some Arrsers might find it of interest:

Operation 'Sealion' - The German Plan of Invasion — Defence Academy of the United Kingdom

Le Chevre

 

[maguire]

'German Plans for the Invasion of England in 1940, prepared by Admiral Kurt Assman for the British Admiralty from German documents'

kurt assman...hurrrrrr

 

[TamH70]

Yup, funny. Even funnier is the high ground near Berlin called the "Seelowe Heights".

Hills, miles from the sea, named after Sea Lions.

Tam

 

[jonwilly]

My old dad, Gunner, kicked out at Dunkirk used to say that if Hitler had done an immediate follow up then they would have taken UK, 'We Had nothing'.
I have read the views of Brigadier Sir Jack Smyth who was commanding a UK Brigade at this time and he says a German invasion in the first few months after Dunkirk would have been very hard to resist.
By August September, the time had been well used and Herr Hitler would have had a hard task on his plate and I doubt he would have been successful.

john

 

[Steven]

Always been lead to belive that the Germans problem would have been actually getting enough troops across the channel what with the RN getting in the way.

 

[jagman]

Always been lead to belive that the Germans problem would have been actually getting enough troops across the channel what with the RN getting in the way.

Yup. The RN was still pretty much the biggest and meanest navy in the world at that time.
Air supremacy on the Germans part wouldn't have prevented the RN from decimating anything in te Channel. If Sealion had gone ahead the Navy would have been in the thixk of ot regardless of losses to the Luftwaffe.

 

[Vastatio]

Am I correct in thinking that one of Hitler's reasons for cancelling SEELOWE was in order to concentrate on BARBAROSSA?

 

[TamH70]

From Vastatio:
"Am I correct in thinking that one of Hitler's reasons for cancelling SEELOWE was in order to concentrate on BARBAROSSA?"

Yeah, mate, that seems to be the stated opinion of most historians. I think perhaps it was because he couldn't rely on the Luftwaffe to provide air cover for any invasion as they had not succeeded in breaking the will of the British to fight on, and, crucially, failed to defeat the Royal Air Force. Plus the fact he could not trust Goering.

In choosing to go ahead with the planning for Fall Barbarossa without having secured his western flank, (by knocking out the British from the war), he made his most crucial mistake of that conflict.

Tam

 

[jim30]

I think it would have failed - simply because the Germans had done no practise at amphibious ops, and had no plans on how to keep the channel open. They could have got a first wave across in the assorted vessels they'd comandeered, but then they would have struggled to keep the lines open day in day out for weeks to supply the troops. The Luftwaffe didn't have enough airlift to sustain them (saw the sums done on this somewhere). The result would have been a German bridgehead taking fire, with rapidly reducing supplies and a seriously hacked off RN tearing shreads out of the invasion fleet.

Look at D-Day as an example of what is needed to do a proper landing - then look at the Seelowe amphib fleet. You can see its doomed to failure!

I think the one thing that would have worked would have been a parachute landing in the SE immediately post dunkirk, forcing the UK into pnaic and making them sue for peace.

 

[Cuddles]

It is a long and dificult journey from Scapa to the Channel. Large parts of the journey would have been at threat from air superiority from Germany, Norway and Holland. U-boats would have been hunting in packs and the Hun still had two viable major surface units. assuming the RN would have been a deal-breaker is a bit of a flight of fancy - remember POW and Repulse.

 

[Magdovus]

I hear what you're saying Cuddles. I heard something from a naval type saying that the RN would have used MTBs and the like and the wake from the would capsize the flat-bottomed barges as they were towed across the Channel. MTBs were nippy enough to give the Luftwaffe a headache too. If the Crabs had been able to provide any kind of air cover then it would have been... err.... interesting times!

 

[johnboyzzz]

The Luftwaffe was able to sink only 4 of the 39 Royal Navy destroyers which took part in the escape from Dunkirk and the Royal Navy already had 17 destroyers and 3 light cruisers based within the Channel . The German plan demanded rather a lot from the Luftwaffe.

 

[llech]

There were only 40 yes 40 Tommy guns in the whole of the U.K. the only fully equiped divison in Britain was a Canadian one, virtually no heavy weapons all the latest tanks (for what they were) were left behind. Unbelivebly Factories hadn't been put on war footing. It really was back's against the walls time, even the RAF were grateful that London was getting Blitzed. Dark days indeed.

 

[4(T)]

IIRC the RN actually had more than 80 warships in striking range of an invasion - most of them fast craft from MTBs up to cruisers.

Given that - in the event of an attempted invasion of UK - the RN would likely have attacked without any regard for cost, the Luftwaffe would have been entirely unable to prevent them reaching and wiping out the primitive and slow fleet put together for Sealion. By the time the RN's units were mixed in with the invasion fleet, its unlikely the Luftwaffe would even have been able to discriminate friend from foe in the melee.

 

[P2000]

The Luftwaffe presented a different air threat to that which cost the RN POW and Repulse. The Germans' principal means of air attack against ships were JU87 dive bombers, and medium sized level bombers.

Take Op PEDESTAL (one of the Malta convoys) as an example of the ability of Axis air forces. In 6 days' fighting the Allies lost:

-1 aircraft carrier sunk, (EAGLE, to U73)
-2 light cruisers sunk, (MANCHESTER, scuttled after being torpedoed by E boats, CAIRO torpedoes by an Italian submarine)
-1 destroyer sunk, (FORESIGHT, torpedoed by an Italian aircraft)
-1 aircraft carrier damaged,(INDOMITABLE)
-2 light cruisers damaged (KENYA and NIGERIA - both torpedoed by submarines)

The Axis powers deployed 784 aircraft against the convoy, and achieved the sinking of one destroyer. The air threat from Italian and German air forces in the early part of WW2 against the RN was very much less than that presented by the Imperial Japanese Navy. I'd argue, Cuddles, that you're overstating things.

 

[maguire]

jokes aside, Derek Robinson's book 'Invasion 1940' goes into this in some detail (and is a good read as well) - there were only a few viable places for the landing, and as people have said, the RN would have decimated the barges of an invasion fleet very quickly indeed.

 

[johnboyzzz]

The German invasion barges were inadequate. The barges from the Rhine and elsewhere to carry their landing force to England were flat-bottomed and unsuitable, liable to sink, in even slightly rough seas in fact, many of the craft would probably have been sunk by the wake of passing fast destroyer as well as getting blatted by the RN and straffing by the RAF

 

[llech]

I would have thought crafty Jerry would've made an Air Bridge pretty much in the same vein as Crete, the barges wouldn't have been a D-Day style assault more Consolidation of Forces.

 

[tutankhamun]

There is an excellent book by Derek Robinson called "Invasion1940" which covers this. His basic point is that even without the RAF the invasion was doomed. The Navy would not have staying in port, even with no air cover. The Germans had 6 surviving destroyers to protect the fleet we had something like 60. The fleet was planned to be tugs pulling river barges at 2 to 3 knots.

OOPs, apologies to Maguire for repeating his comments, should have read all the thread first.

 

[4(T)]

There were only 40 yes 40 Tommy guns in the whole of the U.K. the only fully equiped divison in Britain was a Canadian one, virtually no heavy weapons all the latest tanks (for what they were) were left behind. Unbelivebly Factories hadn't been put on war footing. It really was back's against the walls time, even the RAF were grateful that London was getting Blitzed. Dark days indeed.

The "defenceless UK" is heavily mythologised.

Immediately after Dunkirk, UK actually had in excess of 20 Divisions available to meet an invasion. Admittedly many/most of these were weak at down to 50% strength, but thats still a very substantial force to deal with a limited German (airborne or seaborne) bridgehead bottled up in the limited manoeuvre room available to them in Kent and the south east coast. The pooled residual artillery and armour available in UK was not insignificant, even after the losses in France. Same with small arms - UK's chronic shortage of rifles was actually as measured against projected recruitment of c.4 million servicemen. UK at that time had about 1 million service rifles in store or on issue, of which the thousands lost in France formed only a fraction. In fact the Regular Army remained fully armed to the extent that second-line rifles such as the c.600,000 P14s in store were only ever used in subsidiary roles such as training and Home Guard use. By the Sealion was a realistic proposition in Sep/Oct 1940 - ie by the time the Germans had amassed the shipping needed - UK had substantially re-equipped all of its salvaged Divisions to full strength.