Operation Sea Lion (1974 Sandhurst Wargame)

[Glenn239]

As folks have said, you're great with the numbers and OOB's but when it comes to strategy you do tend to go into pipedreams or hills you choose to die on. Without hindsight, Sealion was more risky. Barbarossa against what appeared to be a very weak and incompetent Soviet military, to get the Germans one true goal of eliminating the threat to the East and get all the Lebensraum they wanted and the long cherished view of eradicating the subhumans of the land they'd be claiming.

Strategy isn't a groupthink activity - I wouldn't give you two pennies for a strategy drawn up by committee. Also, anyone thinking Barbarossa was less risky than Sealion does not understand how to gauge risk.

On paper the Soviets were weak, their performance against Finland was very recent and it was basically a debacle of the highest order. Against a country that couldn't even beat Finland, where you've arguably got the finest army in Europe, and its against your 'real' enemy, this is a far better prospect than drowning a fuckton of your men, buggering up your econimy and wrecking what's left of your navy.

So the Japanese beat the Soviets in 1939 on paper then? Because I'm pretty sure on the real battlefield they lost.

 

[Glenn239]

I agree they need better life preservation kit once they ditch, but I think there still going to be enough friendly boats in the area to get to them in time to make a difference espcially to the earlier BoB chances

SAR recovery rates in 1941 according to that link I posted were 35%, so recovery rates in 1940 will be lower than that. Probably around the zero to 10% mark.

 

[Glenn239]

The waters of the Channel in September are around 60 degrees F. While this is not horrible, if you float around in this for an extended period of time hypothermia is inevitable. The time to exhaustion/loss of consciousness is around 2-6 hours, and perhaps 24+ hours before death. Not arctic levels of instant death, but the key is after as little as 2 hours (unwounded) the person in the water can't assist in their own rescue, and frankly will look like any dead body floating around (of which there would be many). Any injuries, or anything but a flat calm sea and these survival numbers get worse.

I googled the water temperature for the Aegaen in April - it's usually around 60 degrees as well. During the convoy battle in March, survivors were being plucked from the water the next day, so your estimate of a 24 hour survival window (downed pilot or soldier that's jumped off a barge) is probably in the ballpark.

 

[Glenn239]

I’m confused now Glen. If the battle is definitely in September ‘40 and therefore something from ‘41 should be ignored as irrelevant, why have you been referencing things from the Tunisia Campaign in ‘42 or German aircraft production in ‘44?

You're confused at the fact that an air sea rescue service that did not exist until January 1941 would be unable to rescue downed pilots in September 1940?

 

[Ian_W]

So the RN and RAF want to get sucked into a Channel sea line supply battle? That I would highly doubt.

That's mostly because you have absolutely no conception of the critical importance of logistics.

If the British close that sea line, it's over.

And blockading an enemy from resupply is something that the RN has had a lot of practice at.

 

[Deleted member 94680]

You're confused at the fact that an air sea rescue service that did not exist until January 1941 would be unable to rescue downed pilots in September 1940?

Oh dear

 

[CV12Hornet]

I should note that the Germans can keep Royal Navy ships at 500 yards all they want, that’s still “knife fight in a phone booth” ranges when it comes to Naval combat. Even First Guadalcanal, the poster child for close-range melees, was mostly conducted at 2500-3000 yards. 500 yards is plenty close enough for absurd accuracy for the Royal Navy.

 

[soothsayer]

400M+ on hand was not a single pile of .303 that would be depleted but what was 'on hand' ie surplus - they were making a significant number of bullets each week (about 12m a month in June 1940) the majority of which were likely to have been used for training. British production alone was able to keep up with demands with deliveries from Empire stocks excessively exceeding it..

When you read the detail, they were domestically producing 13M, dropping to under 7M and expending 12M per week. The stockpile was created by imports. Leaving the Empire with little.

Without the imports, Britain was going backwards by 16M a month by Aug.

Also a Battalion ToE was 64 Brens - 50 with the Rifle coys 10 with the carrier platoon and 4 with the AA troop - not 36 - although that might not have been the case in Sept 1940 - although production was at 3500 Bren guns a month by June 1940.

Very well aware there were more outside of the sections. I said “just in the sections”. 64 does not make allow for any spares, which the Q store should have to kept the basic 64 going.

The carrier plt is a bit “mythical”. The 9 inf bns should have 100 total (less attachments). 2000 over the 20 odd divisions.

The main point was just issuing a basic load “just to fill SECTION magazines” made that stockpile not that huge.

Eg ~50 x ~1000 x 9 inf bn = 450,000

20 Division need 10 million for a basic load just for brens.

What is interesting is that Britain had nearly 300 Infantry tanks (there was only Matilda IIs in production at this time so these are likely to be all Matilda II) by Mid Sept..

Not correct.
27 Matilda I, 197 Matilda II in Sept ‘40
(50 Matilda II sent to Nth Africa in Aug ‘40)

And given the difficulty that the Germans had of stopping them in 1940........

The Army Tank Bn.
BHQ 4 cruisers

3 Squadrons
SHQ inf tk & 2 CS tks.
5 tps of 3 inf tks, Sqn carriers (3)

4 Cruisers, 48 inf tks, 6 CS tks
(54 matilda II)

There is just enough for 3 bns
(162 and 33 spares / training)

 

[soothsayer]

First the forces you say are at Portsmouth were at Plymouth as far as I know and with Revenge's limited speed could take in excess of 12 hours to get to the invasion area. Secondly any forces as far north as Rosyth would take 18 or so hours to get to the straights of Dover. None of these would be available to intercept the initial landing BUT would come into play in preventing reinforcement and resupply. That is why, in the game, it was felt the landing would take place but resupply was impossible and also, I guess, why on numerous occasions the Admiralty gave their opinion that it was doubtful they would be able to stop the first wave.

The following explains it clearly.

Chapter 4!!!

Germany will need to position its chess pieces FIRST, before crossing.

While the armada is coastal or in port, it can be raided, air and sea (at night) but will be heavily protected.

The RN must wait till clear indication of true invasion, not bluff or training, before committing units, especially in day light.

 

[Ian_W]

The following explains it clearly.

Chapter 4!!!

Germany will need to position its chess pieces FIRST, before crossing.

View attachment 456386

Note that letter is not from 1940 - just reading the dates, it's from 1941 if not 1942.

And doing so will be very obvious - notably the Germans are going to need to spend rather a lot of their light forces to establish the protective minefields.

"For the tactical minefields planned by the Naval Staff to protect the flanks of the crossing area, a total of 6,800 mines, including 800 dummy mines, and the necessary anti-sweeping equipment had been ready by the 4th September. The transfer of this gear to the operational harbours was in process, and would be definitely completed by the 19th September. It was intended to carry out the mine-laying operations in the period D - 8 to D 2; the intended position of the minefields can be seen in the sketch overleaf"

https://www.cia.gov/library/readingroom/docs/GERMAN PLANS FOR INVASION OF ENGLAND, 1940_0001.pdf p47

The capability of the Germans to protect said armada from the sea is also pretty darn limited, as the loss of 80 barges on 13 September shows.

"British attacks increased on the Channel ports, where the invasion preparations were observed. The German air defence was not strong enough to prevent reconnaissance. Considerable, losses were sustained by the Germans. In Ostend three motor torpedo boats were put out of action by bombs, and on the 13th September an air attack resulted in the sinking of eighty . barges. . In addition, the naval measures, mine-sweeping operations and the assembly of the transport fleets at the embarkation ports were repeatedly interrupted by the R..A.F" (ibid, p57)

 

[fourthmaninaboat]

The following explains it clearly.

Chapter 4!!!

Germany will need to position its chess pieces FIRST, before crossing.

While the armada is coastal or in port, it can be raided, air and sea (at night) but will be heavily protected.

The RN must wait till clear indication of true invasion, not bluff or training, before committing units, especially in day light.

Firstly, this letter is from March 1941, after the period of greatest danger, and secondly, it's from the War Cabinet, not the Admiralty. This is a political document, not a military one, and doesn't really describe the Navy's planning. While I agree that the RN is unlikely to commit units in daylight until it is clear that an invasion is ongoing, it was very willing to commit units at night to harass the gathering invasion forces, including Revenge on one occasion.

 

[Alanith]

Note that letter is not from 1940 - just reading the dates, it's from 1941 if not 1942.

And doing so will be very obvious - notably the Germans are going to need to spend rather a lot of their light forces to establish the protective minefields.

"For the tactical minefields planned by the Naval Staff to protect the flanks of the crossing area, a total of 6,800 mines, including 800 dummy mines, and the necessary anti-sweeping equipment had been ready by the 4th September. The transfer of this gear to the operational harbours was in process, and would be definitely completed by the 19th September. It was intended to carry out the mine-laying operations in the period D - 8 to D 2; the intended position of the minefields can be seen in the sketch overleaf"

https://www.cia.gov/library/readingroom/docs/GERMAN PLANS FOR INVASION OF ENGLAND, 1940_0001.pdf p47

The capability of the Germans to protect said armada from the sea is also pretty darn limited, as the loss of 80 barges on 13 September shows.

"British attacks increased on the Channel ports, where the invasion preparations were observed. The German air defence was not strong enough to prevent reconnaissance. Considerable, losses were sustained by the Germans. In Ostend three motor torpedo boats were put out of action by bombs, and on the 13th September an air attack resulted in the sinking of eighty . barges. . In addition, the naval measures, mine-sweeping operations and the assembly of the transport fleets at the embarkation ports were repeatedly interrupted by the R..A.F" (ibid, p57)

Don’t you know, Herr Glenn has assured us that the luftwaffle can protect the invasion convoy with over one million sorties a day!!

 

[Ian_W]

Don’t you know, Herr Glenn has assured us that the luftwaffle can protect the invasion convoy with over one million sorties a day!!

Glenn is an SIS agent, doing his utmost to help Britain win the war by convincing Germany to keep wasting blood and treasure trying to invade.

 

[Carl Schwamberger]

...
The Italians laid considerably more mines in the Sicilian Channel; at the time of Pedestal, they had laid fields containing more than 11,000 mines in the area (2,320 between Sicily and Pantelleria, 1,020 between Pantelleria and Tunisia, 6,880 between the Aegadian Islands and Cape Bon, and 1,040 between Bizerte and Keith Rock). By Torch, these had been further strengthened. While parts of these fields had decayed or been swept, they were still a considerable barrier to the Allies; the 1,170 mines deployed in December were an addition to these fields, rather than being the only fields laid.

There is also a considerable difference between minelaying of this scale off a friendly coast and off an enemy one. Trying to lay a minefield close to the English coast would risk provoking a British response (meaning that the minelayers could be sunk or otherwise rendered incapable of participating in future operations, such as laying more fields or escorting invasion convoys) and allow the British to learn the position of the field and sweep it. There would likely be a safe channel close to the English coast for destroyers to use. The British also continued minesweeping operations in the Channel throughout the war, unlike in the Sicilian Channel, which was only cleared in parts, when needed for convoy passages and the like. It was a lot easier for the RN to sustain sweeping operations in the Channel, close to RAF bases and RN support, compared to the Sicilian areas, dominated by Italian naval and air bases. Mines would be a risk, yes, but they were one the RN could deal with. ...

Taken a look twice the last two months at the Italian Minefields in the Sicilian Channel, & I'm not seeing a good argument for a minefield massacre. In terms of ships actually damaged or sunk they are the dog thats not barking. It must have taken the Brits some effort to sweep passages in front of the assorted convoys that passed. Evidently the effort was worth while. The list of ships lost to those mines is notable for its brevity.

Whatever the Germans can lay in the Channel is not looking like a dangerous barrier in this battle.

Changing the subject...

In the air I'm not seeing a serious show stopper with the German AF vs the RN in the Channel. To start with the Germans of 1940 were not very good at attacking ships. I know that statement will cause the fanboys to fall to the floor in a tantrum but the numbers just don't add up. Hell, when the RN made a show of force sortie into the North Sea in October 1939 the German pilots could not even find the task force. I expect in the clear weather and target rich waters of the September Channel they could find targets. (I'm not even going to touch fratricide at this point.) A few weeks earlier in the 'Kannalkampf' we get results like this. Numbers for air sorties, bomb weight, & mines laid from Hooten. Numbers for attacked/sunk are from misc web sources. If anyone has better sources/numbers I'd like to have them.

The most relevant section might from the August/September lines. In the August aggregate of bombing and mine laying sorties you get 97 sorties per sunk ship and a still unimpressive 61 per in September. Defensive air cover varied through all this. I suspect the ships actually hit or sunk were on days RAF air cover was lacking. Most of the sunk were cargo transports & relatively slow and inferior in maneuver. Using the September ratio for this theoretical amphib op the at best 600 German bomber sorties on the first day could sink ten Brit warships. Tho air cover, higher ship speeds, and better maneuverability are liable to halve that.

Using a example where Axis air groups had two more years of experience attacking ships: On the first day of Op PEDESTAL the Axis sortied 180+ aircraft vs the cargo convoy and covering force. CAP from the carriers in the covering force was effective & three hits were scored. One hit on the armored deck of a carrier, putting it out of action for the battle. Another carrier was hit but undamaged. The other on a escort. After the carriers/air cover was withdrawn the crack axis airmen flew 145+ bomber sorties. Six or seven hits on the Brit cargo and war ships were made, including a pair of dud torpedoes. Two of the aircraft has sank ships. More might have been hit, but the convoy made it to under Spitfire cover from Malta & the Axis air attacks tapered off. I did not make a close count of the attacker losses in these attacks. Combat & operational losses, plus those returned to the airfields but written off seem to run between 10% & 15% each day.

 

[alfredtuomi]

whenever i read this i am reminded of the dolphins in no name harbour on key biscayne.just before dusk every evening they would come in and herd all the mullet into one small group and then one at a time have a feeding frenzie while the rest kept the mullet bunched together.
i would expect the RN to attack from the rear of any convoy taking out the larger escorts first and then working their way through the panicked crowd.
As for the siebel ferries it seems the first prototype was tested august 31st the next pair on september 4 and then production was BEGUN in september with 25 completed by the end of the month so realistically their would be none for a september 15th UMS.

and of course once/if the landings are made hte RN can just wait for the lemmings to slowly come to them.

 

[fourthmaninaboat]

Taken a look twice the last two months at the Italian Minefields in the Sicilian Channel, & I'm not seeing a good argument for a minefield massacre. In terms of ships actually damaged or sunk they are the dog thats not barking. It must have taken the Brits some effort to sweep passages in front of the assorted convoys that passed. Evidently the effort was worth while. The list of ships lost to those mines is notable for its brevity.

Whatever the Germans can lay in the Channel is not looking like a dangerous barrier in this battle.

Part of the reason for the lack of sinkings to these fields is that the RN often refused to risk them, letting aircraft and submarines do the work of harassing Italian convoys; that said, there were concerted sweeping efforts before convoys. The escorts were also equipped with minesweeping equipment, and for Pedestal, so were the merchants (with paravanes for self-defence).

Changing the subject...

Good stuff; I've looked at German air attacks on British destroyers before, but I didn't have good numbers on German sortie generation to contextualise things. For attacks on RN warships, Ships Damaged or Sunk by Enemy Action is a good source.

 

[Johnrankins]

Assuming that the British don't immediately throw in the towel (which I believe is what the Germans would have been counting on - in the same way that the Japanese had been counting on the Chinese doing after Nanking - like the Japanese the Germans would have been disappointed)

Nonsense, as any Mel Gibson movie shows, the "Cowardly Brits" throw in the towel, after using their valuable time killing widows and orphans, the moment anyone as tough as Mel Gibson shows up.

 

[Carl Schwamberger]

... For attacks on RN warships, Ships Damaged or Sunk by Enemy Action is a good source.

Thanks

Nonsense, as any Mel Gibson movie shows, the "Cowardly Brits" throw in the towel, after using their valuable time killing widows and orphans, the moment anyone as tough as Mel Gibson shows up.

You mean drunken egotistical actors?

 

[Johnrankins]

You mean drunken egotistical actors?

You know there is nothing tougher than drunken, anti-semetic, egotistical actors, right?

 

[Johnrankins]

The barges the Japanese used in the Pacific were much sturdier than the river barges (powered or unpowered) that would be used for SEALION. Most of the river barges were either wood hulled or thin steel, both of which a .50 round will penetrate quite nicely thank you. The standard Type A barge used for interisland transport had a diesel engine, a range of 100nm at 7.5kts, they were 14.3m long and a beam of 3m. The powered barges used in 1940 were roughly 38m long and 5m wide, older ones were wood newer ones steel - they were quite slow especially when loaded, and to make them "seaworthy" the Germans welded two of them side to side...

It is almost like they were seaworthy, naval barges instead of civilian river barges.