SeaLion as a diversion?

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phylo_roadking
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Re: SeaLion as a diversion?

#16

Post by phylo_roadking » 13 May 2009, 19:11

Also, given enough ships as targets, it could take much if not all of the luftwaffe sorties to sink or destroy all of the RN flotillas. Using the 1944 Pacific campaigns as a guide, USN carrier based attacks took close to a 1000 sorties to sink IJN flotillas of 8-10 destroyers. Those are small, dedicated strikes by the elite of the USN carrier based air arm, using planes and tactics designed for just that sort of attack. The Luftwaffe is not that far along and would be forced to use a lot of medium bombers at low levels, dropping level bombs.
As I mentioned above - Norway and Crete both illustrated during the war the number of sorties that needed to be flown in what aprticular circumstances for the RN to lose ships...and THIS time they'd have to be flown within reach of Fighter Command's Eleven Group 8O

One thing to remember is...the RAF would have a much easier time attacking the "invasion fleet" from the air than the LW would have attacking the RN. The LW would be attempting to sink fast-moving destroyers firing back at them...the RAF will be bombing slow-moving cargo ships and river barges rolling in the unacustomed swell :lol: Not quite fish in a barrel compared to what the LW had to do - but close!!!

Sid Guttridge
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Re: SeaLion as a diversion?

#17

Post by Sid Guttridge » 14 May 2009, 11:08

Hi Konig_pilsner,

It would only take a few hours for any fake invasion force to reach the shores of South-East England. It would thus be discovered as phoney long before any major British warships could intervene. If it persisted in bobbing about aimlessly in the Channel this would also give the game away, besides being vulnerable to both vulnerable to air and light surface force interdiction.

Cheers,

Sid.


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Re: SeaLion as a diversion?

#18

Post by Polynikes » 15 May 2009, 00:25

Not only that but there wasn't enough shipping to mount an invasion in the first place.

If the river barges are swamped by the Channel and what remains are beached in SE England...how is the German army to land a real invasion?

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Re: SeaLion as a diversion?

#19

Post by phylo_roadking » 15 May 2009, 15:42

If the river barges are swamped by the Channel and what remains are beached in SE England...how is the German army to land a real invasion?
Isn't that one of the problems with the historical Sealion? :wink:

OTL, they poured concrete ballasting into barges, to trim them and provide decking for heavy vehicles. A majority were actually NON-powered, and would have been brought across in strings by tugs or motored barges; at the far end they would have been run ashore by their tugs. The plan THEN was that the motored barges or as many of the non-motored ones as posible would be refloated at the NEXT high tide and carry a followup waves of troops and materiel. So unless facilities of some sort could be captured to allow quayside unloading...reinforcements in bulk meant waiting for that next tide, THEN a slow trip BACK to France for embarkation of cargo/troops and ANOTHER slow trip BACK to the UK to repeat the running-aground 8O

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Re: SeaLion as a diversion?

#20

Post by Von Schadewald » 16 May 2009, 21:40

At a pinch, Bismarck could have been ready for action in late 1940. Could the Germans have been able to make any use of her as part of this trap?

Image

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Re: SeaLion as a diversion?

#21

Post by phylo_roadking » 16 May 2009, 23:53

Not by "late" 1940. Any diversion or real invasion would have to be mounted BEFORE the Autumn gales and deterioration of the weather in the Channel from late September onwards; long argued as one of the reasons for Hitler calling off the 1940 Sealion - if he ever really intended it :wink: If a diversion had been made during the late Autumn or Winter months, when getting fully-laden barges shephered across the Channel would have been suicide, the British would have smelled a rat.

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Re: SeaLion as a diversion?

#22

Post by Sid Guttridge » 19 May 2009, 11:00

Hi Guys,

I would suggest that the threat of SeaLion might be a more useful diversion than its actual execution. For example, it could keep the British preoccupied with their own national security while the real German effort was switched to the Mediterranean.

Cheers,

Sid.

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Re: SeaLion as a diversion?

#23

Post by mescal » 19 May 2009, 13:06

Hello,

The threat of an invasion did not prevent the Royal Navy from reaffecting some of its ships to other areas in the summer/fall of 1940

Below is a chart showing the proportion of "active" ships of the Royal Navy between sept 1939 and december 1940.
That is, the ships in the yard, or in training are not taken into account to compute the proportion, as I feel that the Admiralty was more interested, in case of an invasion, to have ships immediately available, and not in 2-3 months.
(I use the proportions instead of numbers, because it makes it easier to read and compare).
RN_units_Home_39_40.jpg
RN_units_Home_39_40.jpg (72.34 KiB) Viewed 596 times
It is clear from this chart that the Admiralty thought that they had enough margin of superiority to accept a decline in its relative strength in the Home waters - many DDs in particular were reaffected to the Med at this time.
And this decline happened when Sealion was still a threat.

Looks like to me that at least the Royal Navy was not ready to buy any German bluff on this matter.


Note also that the first Winston's Special convoys left UK before it was clear that the German had given up any hope of invading.
(AP1, AP2, AP3, WS1 and WS2 all sailed in august or before.)
Olivier

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Re: SeaLion as a diversion?

#24

Post by phylo_roadking » 19 May 2009, 15:05

Olivier, is the Destroyer peak at the beginning of May 1940 against the TOTAL available at that time? I mean - does the sharp fall from the beginning of MAy take in combat losses to DDs in Norway and France? Or is it just the percentage of the total force available in "British" waters?

The peak in mid-July....is that BBs returning to British waters after Mers-el-Kebir?

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Re: SeaLion as a diversion?

#25

Post by mescal » 19 May 2009, 16:03

Hi Phylo,

It's a proportion of the seaworthy & combat-capable destroyers :
Example :
May : 125 out of 163 gives the 77% in the chart above.
If I compute the percentage against ALL DDs (including those in dockyard and in training it gives te same 125 against this time 187, that is 67%).

Here are the percentage of DDs in Home Waters against ALL DDs :
Apr : 62%
May : 67%
Jun : 49%
Jul : 43%
Aug : 40%
Sep : 33%
Oct : 23%
Nov : 19%

(Full data are here)

Regarding the BBs, I do not have the time to check right now, but from memory, I think that both Nelson & Barham went out of the yard at roughly this time (summer 40), and since they were in the yard in UK, they "reappeared" in home waters.
And since there were only 15 BB (and among those QE & Valiant were not availabale in this time period because of reconstruction, which leaves us with a sample size of only 13), 2 ships can easily shake a trend.
I gave this data on BB just for illustration -- statistically, it's rather meaningless.
Olivier

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Re: SeaLion as a diversion?

#26

Post by LWD » 19 May 2009, 17:53

Didn't the British send at least one squadron of Hurricanes to Africa during the BOB? I don't see that Sea Lion is much of a threat if the LW isn't engaged in the BOB and if it is then it's not available to help in the Med. Also if it's not available then the RAF can put more effort and effect into sinking anything that might be used to carry an invasion fleet. If the barges are to be kept in France as targets it certainly isn't going to help the German economy.

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Re: SeaLion as a diversion?

#27

Post by phylo_roadking » 19 May 2009, 18:38

If the barges are to be kept in France as targets it certainly isn't going to help the German economy
IIRC there were at least two occasions historically when complaints about the effect this was having reached Raeder.

I've never seen figures for what economic damage was actually done by Bomber Command's "bargebusting" :wink: but they destroyed hundreds, so it can't have been negligible. It must have reflected in riverine cargo traffic totals vs numbers of barges/available tonnage through the end of 1940 into 1941.
I don't see that Sea Lion is much of a threat if the LW isn't engaged in the BOB
LWD, this is my point above; attempting a BLUFF without attempting to bluff an air supremacy battle TOO would be a dead giveaway. Of course...it has often been argued that this IS what happened historically :wink: :lol:
then it's not available to help in the Med.
We-ell...in the summer of 1940 what was later in the year to start happening in the Balkans and North Afrcia - Mussolini's failures dragging the Germans into both locations - couldn't be foreseen :wink: I'm tempted to say that what happened to the RA "expeditionary force" in the Battle of Britain would have given the Air Staff great reason for future confidence in the capability of the RAF in the campaign against Italian Libya! :wink:

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Re: SeaLion as a diversion?

#28

Post by Sid Guttridge » 20 May 2009, 12:48

Hi mescal,

From your link it appears that about one in nine destroyer months were spent in the Mediterranean in 1940 and about one in six in 1941. Is this approximately right?

Cheers,

Sid.

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Re: SeaLion as a diversion?

#29

Post by mescal » 20 May 2009, 15:00

Hello Sid,

That's it, roughly.

Here is a table of the number of Destroyers in the Med & in the Gibraltar area for 1940 & 1941 :
RN_DD_Med_40_41.jpg
RN_DD_Med_40_41.jpg (133.48 KiB) Viewed 524 times
(keep in mind that Gibraltar is a bit tricky, as the ships may be either in the Atlantic or in the Med).
Olivier

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Re: SeaLion as a diversion?

#30

Post by princeliberty10311517 » 09 Jun 2009, 20:19

Sid Guttridge wrote:Hi Guys,

I would suggest that the threat of SeaLion might be a more useful diversion than its actual execution. For example, it could keep the British preoccupied with their own national security while the real German effort was switched to the Mediterranean.

Cheers,

Sid.
Make sure Churchill sees lots of photos of troops massing on the beach, and things that look like landcraft being massed.
And do lots of radio communications about mass production of landing craft etc..

Then proceed in the Med.

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