Operation Sea Lion (1974 Sandhurst Wargame)

Discussion in 'Alternate History Discussion: After 1900' started by Not James Stockdale, Mar 8, 2019.

  1. Not James Stockdale Those Protestants... Up to no good, as usual

    May 3, 2016
    I know the outcome of this kriegsspiel is considered sacrosanct by the British members of this board, but I have some questions raised by the Wikipedia article and other material and most of the links there have long since died.

    The game was played as a time-accelerated real-time match, characteristic of kreigsspiel, with the Germans declining to launch their first echelon on the first two simulated days. However, British ground forces were able to use those days to immediately begin the movement of reinforcements to the South East, largely negating the Luftwaffe's destruction of the railroads in Kent and Sussex. The British therefore had a two-day head start rather than the two-day late start they might have had if they began the movement of forces upon confirmation of a German landing along the entire Kent/Sussex front rather than concentrated around Dover. Did this movement of British forces happen in OTL September 1940, or would it have occurred upon confirmation of German embarkation or landing? The German assault points would not have been immediately known, so reinforcing units would have had to have been routed via staging points, likely south of the Surrey Hills, before moving directly to confront advancing German forces.

    It's well known that, in the game, the German second echelon was stopped by a British force of 17 cruisers and 57 destroyers. We also know that the Home Fleet would not have sent battleships into the Channel unless the Germans sent their own battleships in. Where did these cruisers and destroyers come from? Was it the equivalent of the Great War Harwich Force? I find it hard to believe that the Home Fleet would have left their battleships alone in Scapa Flow, especially if they were concerned about a possible attempt by German battleships and cruisers to break out into the Atlantic.

    The limitations of the unpowered invasion barges are well known, although I have also seen claims that such barges can be used in up to Sea State 5. Apparently, there were different shipping plans discovered after the 1974 wargame that implied the use of more than four thousand ships, including many powered ships, rather than the approximately 1,500 river barges used in the wargame. Is there anywhere to find more information about that?

    I have also heard complaints about the inability of the German side to use the Luftwaffe for close air support as had been done in France, the fact that German air attacks were concentrated on London, ostensibly in some sort of attempt to draw off RAF fighters, and the fact that the Germans either did not or were not allowed to use captured airstrips in the South East as bases or even as pseudo-FARPs.

    EDIT: Just to clarify the poll, I am talking about the initial assault itself. In the Hague option, German troops are unable to defeat the British garrison. In the Crete option, they defeat the garrison, regardless of whether the British attempt to retake the island.
    Last edited: Jun 5, 2019
    Evil Crusader, Leede, Jearom and 7 others like this.
  2. Ashley Pomeroy Member

    Feb 21, 2006
    Wiltshire, England
    Regarding the Luftwaffe, I think the general consensus is that the German air force might have been able to defend the landing beaches from air attack, or support the troops with air strikes against ground targets, or supply the troops from the air, or attack the Royal Navy in the channel - but they didn't have the capacity to do all four at once.

    Strip away the Luftwaffe, strip away artillery and tanks, and my hunch is that even if a substantial force could have been landed there would have been no way to supply it, and even against Britain's limited resources post-Dunkirk it would still mostly have been light infantry versus tanks and field guns.

    I've always wondered what the German soldiers were supposed to drink. Just that one thing. Supplying eighty thousand soldiers trapped on a beach in the south of England with water would have been a major undertaking. Three litres of water times eighty thousand equals almost half a million kilograms of water every day, if my maths are correct. Perhaps not on the first day. On top of food and ammunition. They could have tried sourcing it from local supplies but even that wouldn't have been easy.
    Last edited: Mar 8, 2019
  3. King Augeas Well-Known Member

    Mar 25, 2012
    IIRC, the German plan involved spending several days forming up invasion convoys outside the Channel ports, of which Calais was in line of sight of an observer at Dover.

    So that would give plenty of time for reinforcements to be sent south of London, although they wouldn't know exactly where to go.
  4. Cryhavoc101 Well-Known Member

    Jun 27, 2014
    1123 6536 5321
    There was in addition to the regular Naval forces hundreds of Auxiliary vessels - from purpose built Armed trawlers to ships taken into service often armed with 12 pounders and some MGs and private motor launches taken into service as well as MTBs and MGBs

    These alone would have taken a toll of any invasion fleet and could conceivably have defeated the invasion on their own before we even consider the regular forces of the RN.

    Each night during the 'invasion scare' 100s of these light vessels were abroad patrolling the channel, peaking into French harbours, patrolling for surprise invasions and the like - just as light vessels had done during the wars of the 18th and 19th C

    As for landing and supplying enough for the first waves - I think we only have to look at the extensive efforts made by the components of Operation Neptune to land and supply the troops for D-Day as well as the massive logistical effort to maintain the forces in Normandy across the beachhead and compare it to what the Germans had in the late summer of 1940 to realise that Op Sealowe had epic disaster writ large all over it.
    TheReformer, Leede, Geordie and 11 others like this.
  5. misterwibble Well-Known Member

    Feb 18, 2015
    I seem to recall one of the rules for the game was that the Royal Navy would not intervene for the first twenty four hours, as it was felt that otherwise the German forces wouldn't even get ashore.
  6. Stenz Don't judge the past by the standards of today... Monthly Donor

    May 18, 2016
    Leafy Southern Blighty
    I'm no expert, but from the website Naval History, subsection World War 2 at Sea ORGANISATION OF THE ROYAL NAVY 1939-1945:

    Generally regarded as the most prestigious of the home command, Portsmouth Command was responsible for the middle part of the English Channel between Newhaven and Portland. This area remained unchanged during the war. It was the main assembly area for the naval forces involved in the D-Day landings. Those forces were under the command of the Allied Naval Expeditionary Force commander [Admiral Sir Betram Ramsay], and not under Portsmouth Command.

    The ships under command in 1939 included:
    at Portsmouth:
    Local Destroyer Flotilla [8 destroyers of various classes]
    5 destroyers attached to HMS Vernon
    1 old battleships and 1 cruiser attached to HMS Vernon
    2 minesweepers attached to HMS Dryad
    The 5th Submarine Flotilla was based at Gosport
    at Portland:
    First A/S Flotilla of 1 sloop, 3 destroyers, and 6 corvettes
    Fishery Protection & Minesweeping Flotilla with 2 sloops and 12 minesweepers
    The 6th Submarine Flotilla was based at Portland.
    The Reserve Fleet included 1 old aircraft carrier, 9 cruisers and 15 destroyers.
    Ships in refit included 1 battleship, 1 battlecruiser, 4 cruisers, 2 destroyers and 1 submarine.
    The following squadrons and flotillas served in the command during the war.
    The Channel Force, Portland 3.9.39-7.10.39 [drew vessels from both Portsmouth & Plymouth]
    3rd Battle Squadron
    2 aircraft carriers & 2 old cruisers
    12th Destroyer Flotilla & 18th Destroyer Flotilla
    16th Destroyer Flotilla [V&W] -8.40
    18th Destroyer Flotilla [A class] -10.39
    1st Destroyer Flotilla [A class then Hunt class] 7.40-5.45
    22nd Destroyer Flotilla [old S class] 7-11.40

    retitled PLYMOUTH COMMAND 2.41-
    Plymouth Command was responsible for the western Channel, the South-West Approaches, Bristol Channel and the Irish Sea. In the expectation of major convoy movements from the Irish Sea around the south of Ireland, the command was renamed Western Approaches Command on the outbreak of war. The German occupation of northern France in the summer of 1940 made convoy routing around the south of Ireland too hazardous. All convoys had to move into the Atlantic via the north of Ireland.
    As a result, the command headquarters at Plymouth became too remote. The convoy protection role was allocated to a new headquarters at Liverpool which became the new Western Approaches Command in January 1941. Plymouth Command reverted to a more geographically restricted role of protecting the south-west coastline. In 1943-1944 more active operations against German naval forces were begun with the establishment of a cruiser-destroyer striking force.
    Ships allocated to the command 1939:
    Emergency Flotilla - 3 destroyers
    Training duties - 1 aircraft carrier, 1 destroyer
    Reserve Fleet:
    1 aircraft carrier, 6 cruisers, 1 minelayer, 14 destroyers
    In refit - 2 battleships, 2 cruisers, 4 destroyers, 1 sloop, 1 minesweeper
    In September 1939, the command was allocated:
    part of the Channel Force - 2 aircraft carriers, part 18th Destroyer Flotilla
    11th Destroyer Flotilla
    17th Destroyer Flotilla

    Flotillas allocated 1939-1945:
    5th Destroyer Flotilla. 9.40-3.41
    11th Destroyer Flotilla-11.40 to escort groups
    17th Destroyer Flotilla-11.40 to escort groups
    15th Destroyer Flotilla 10.39-5.45
    10th Destroyer Flotilla 1-12.44
    8th Destroyer flotilla 1.45-5.45

    I make that 45 destroyers, not counting the flotillas, so the 57 doesn't sound impossible and 24 cruisers, so the 17 is certainly in the realms of possibility.
    Leede, Geordie, Ogrebear and 6 others like this.
  7. lordroel Well-Known Member

    Aug 25, 2006
    Once created a entire article about this 1974 wargame, interesting stuff to read how they toughed Sea Lion would end: What if: Operation Sealion, summary of an exercise held in 1974.
  8. Glenn239 Well-Known Member

    Oct 25, 2012
    The naval battle in which the 2nd wave was stopped saw about 1,000 barges out of 1,500 total sunk by 74 warships, or about 13 kills per warship, (in comparison, during the famous Crete convoy battle 7 RN warships with gunnery radar sank at a rate of about 2 targets per warship over 4 hours). Losses amongst the attackers were 2 destroyers sunk by U-boats. No RN warship was sunk by airpower, coastal artillery, or mines in this battle. Given that the battle took place between Calais and Dunkirk apparently in daylight, the sortie rate for the Stukas in support of the invasion should have been around 1,000+ - something like 50-100 hits. Presumably the German team was not allowed to protect its invasion force with the Luftwaffe.
    PhilKearny and Winestu like this.
  9. Cryhavoc101 Well-Known Member

    Jun 27, 2014
    1123 6536 5321
    The main point that you have studiously ignored is that 1 count him, 1, German soldier from that convoy which numbered over 2000 soldiers managed to reinforce the German FJs already on Crete.

    The rest either drowned or were killed or returned to whence they came and only about 100 men arrived at Cape Spatha (from which the 1 soldier managed to 'reinforce' the FJs)

    So less than 0.01% of the expected landing force managed to reinforce the FJs (I bet they were delighted) and just 5% made it to Crete.

    If you are considering that a failure by the RN then in an example where just 1 of 20 vessels arrived then lets extrapolate that to 1500 vessels - so 75 barges make it to the south coast of the UK

    And 50-100 hits - by 1000 sorties?

    During Op Dynamo 6 British and 3 French Destroyers were sunk 4 and 1 respectively by air attack over 10 days and at least 3 of those were stationary or maneuvering very slowly at the time - so about 1 ship every 2 days ;)

    And if the Stukas are focused on badly bombing the Navy then they are not doing any of the other jobs that the mission desperately requires them to do.
    Athelstane, Butchpfd, Leede and 30 others like this.
  10. fastmongrel Well-Known Member

    Aug 5, 2008
    Lancashire UK
    The aquatic mammal has been wargamed a gazillion times and even with silly restrictions on British movements and the Germans allowed to airlift entire Panzer divisions the usual result is about 80,000 to 100,000 Germans get to visit Canada for a 5 year holiday.

    Why didnt Hitler launch the attack. Because even the batshit crazy Charlie Chaplin impersonator knew the chances of success were too low.
  11. Catsmate Well-Known Member

    Aug 10, 2008
    Which included the mustard gas and phosgene that Churchill was eager to employ.
    Butchpfd and Leede like this.
  12. DAv Middle Class... sorry

    Apr 17, 2006
    And the countless gallons of petrol they were able to use to literally set the sea on fire.
    Butchpfd likes this.
  13. oofo Well-Known Member

    Apr 8, 2014
    The “burning channel” concept was essentially just propaganda. Tests were attempted but it was found to be pretty unreliable, so I doubt the tactic would have been employed on anything more than a very local level.
    Leede and eltf177 like this.
  14. DAv Middle Class... sorry

    Apr 17, 2006
    It was managed at a few levels and was noted to have had an effect on German morale. The thought that the British could do such a thing was a disturbing thought to any invading force.
  15. oofo Well-Known Member

    Apr 8, 2014
    Like I said, it had propaganda value.
    Leede, eltf177 and goalieboy82 like this.
  16. Zen9 Banned

    Nov 18, 2018
    It's said that while the 3.7" AAA gun could be used for anti-tank fire it's mounting wasn't built for the job and would be damaged by such use....
    But it's clear substantial numbers of this weapon was already in position in the South-east, even before Dunkirk. ..
    Some Bloke likes this.
  17. Carl Schwamberger Well-Known Member

    Dec 14, 2012
    I wonder if the mounts/carriages were improved along the way. I've found descriptions of them used for direct fire in Africa, and deployed but not used at Salerno, & possibly @ Anzio.
    Butchpfd, Leede and Zen9 like this.
  18. ObssesedNuker Commander of 10 million men

    Jul 8, 2007
    In the Kremlin, Activating Perimetr
    Technically the Luftwaffe wasn't bad at anti-ship bombing, it's just that sinking ships is harder then it seems. As the British are liable to come south as far as possible in the darkness, the Germans get only two, maybe three major attacks in before they're in among the invasion fleet. Keep in mind that even if the Luftwaffe has forced 11 Group to withdraw, the Home Fleet will still have air cover from 12 Group as they come south, so any longer ranged attacks by medium bombers escorted by only Bf 110s would be both less effective and very costly.

    So, assuming that firstly, the Germans concentrate the entirety of their air power for hitting the RN (thus obviously preventing it from doing any of the other tasks it needs to do), the weather co-operates (if it's low overcast then they are fucked), and that the Germans do well by historical norms, then the best case indicates their liable to sink a dozen assorted ships outright and damage another 20. Which still means, going by the 74 warship figure mentioned earlier, the RN has more then 40 completely intact cruisers and destroyers when it rolls into the invasion flotilla and starts ripping it to shreds.
    Last edited: Mar 11, 2019
  19. Lord Wyclif Well-Known Member

    Apr 5, 2012
    The reality is, with all the might that the German war effort could muster, Hitler thought Barbarossa (epic failure in a grand scale) would work and even he wasn’t stupid enough to think that Sealion would.
  20. Cryhavoc101 Well-Known Member

    Jun 27, 2014
    1123 6536 5321
    It or rather certain LW units became better and by 1941 they had a dedicated anti shipping unit in the Med that practiced for it but not in 1940!

    Like I said - they are attacking fast manouvering ships firing back at them and very likely possessed of some form of air cover for most of the day light hours and not stationary or slower vessels as at least 3 of the 5 warships sunk during the Dunkirk evacuation by air power were and that was over a period of 10 days.

    I appreciate that more sorties would be sent at them but also that they would be heavily supported by the RAF

    I am not convinced that the Luftwaffe could do more than damage sink a relative handful of RN ships under those conditions
    Stenz, SsgtC, Johnrankins and 2 others like this.