Operation Sea Lion (1974 Sandhurst Wargame)

[TDM]

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.

You realise that they had to weight the war game massively in the Germans flavor to make it fun if even then still a one sided exercise. So despite you inference regarding British posters here the Brits at Sandhurst were actually turning up with one had tied behind their backs to make this more fun, I.e there was artificial weighting going on, but in the opposite direction to the one you imply.

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.

The British would be able to see the barges embarking in their ports (this leaves aside the point the British would have seen the barges mass even before embarkation*), the invasion fleet would have to form up and would been moving very slowly and there would be no issue tracking them. Now what if there was weather bad enough to obscure them form British coast watch (and naval and air patrols), than OK, but to be honest any weather bad enough to obscure the invasion fleet from discovery is also weather bad enough to mean the invasion fleet itself would get lost or even just be lost.

It actually irrelevant because even if the the first wave of landing 'craft' reach British shores it's hardly game over with a Swastika planted on Buckingham palace.


*This actually happened at one point, they started to consolidate some barges for a test exercise, guess what the RAF flew a mission and bombed them

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.

We know no such thing. That was general policy mainly due to the risk that if you sent Battleships where the German battleships weren't you risked the German slipping their battleships out into the Atlantic (as you say below). In the case of invasion though, yeah the RN is going to deploy because stopping a marine invasion of the home island has been the RN's number one and overriding priority since it was formed.

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.

There was plenty of RN home fleet about. Even if you don't know exactly which beech the German intend to land at, there's actually only so many options due to geography and the speed of the craft. It was going to take 2 days for the barges to get to the closet possible beeches, to expand the possible landing sites would mean extending that time considerably. On top of this remember you talking barges going 3knts vs. destroyers going at 20-25knts.


The battleships are a red herring anyway, they won't be needed.

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.

I doubt it (sea state 2 is nearer the mark), but more importantly I doubt it even more when they are in daisy chains of barges, river boats & pontoons being largely run by press-ganged lowland and civilian river pilots trying to maintain a mass formation by communicating by load hailer, who don't know the waters, crossing the channel under attack (or in weather so bad as to hide them from attack)

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?

It's the same information, the fleet was never just going to river barges and pontoons. Of course the Germans had access to more sea worthy boats, it's just they didn't have enough so they had dilute the invasion fleet with all sorts of less sea worthy boats and actual rafts.

Even then the more seaworthy boats weren't landing craft, but just better boats. So they would still have to either capture a port to off load at or rely on very slow ferrying of the troops as they moored of shore. Ironically the river barges and pontoons could in theory* land on beeches and off load, on the term is actually "run aground" so once they're do that there's no guarantee they'll be able to move off again. (plus of course they have to get to the beech first). This last is important because you have to remember the Sealion plan involved not just the barges and pontoons getting across and landing, but moving off the beech, travelling back to their embarkation points, reloading and repeating the exercise!


*They did a test run, unladen in broad daylight in calm weather. They towed a bunch of then a few miles off a beach and set them to land, in those perfect conditions (clear sky, unladen, no enemy, not after two days rolling on the channel chucking their guts up, not with press ganged pilots, knowing the exact beech to land on) .....50% success rate of getting ashore

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.

OK a few problems with this in general and specifically in comparison to the battle of France

1). this after the battle of Britain so the LW is not in the same state as it was in the Battle of France

2). In the battle of France the RAF was a lot smaller in total than n Sep40 and was only smaller subsection of that as well as operating on foreign territory while ground forces were retreating back towards them

3). In the BoF the LW only had one job to do, in Sealion it frequently gets given lots of jobs to do namely, defend the flotilla, defeat the RAF in the channel, defeat the RN in the channel, contest SE England airspace distract Britain in London help take those airstrips in SE England and so on. (remember it has already recently failed to do only a few of these things a few months earlier)

We're talking about one specific air sea battle during Sandhurst, where 74 RN warships sank 1,000 barges of the 2nd wave in the Channel in broad daylight losing 2 destroyers to U-boats in the process. Given that the Luftwaffe off Pas de Calais in September 1940 should have been able to generate thousands of anti-ship sorties in a maximum tempo effort, how did the umpires decide that no RN warships were lost to air attack?

This the LW that that just lost the BoB yeah? What are the RAF (who they just lost to) doing at this point?

More importantly say they sink a destroyer or two or fuck it lets say five, no ten, how about fifteen and two light cruisers ....so what? You think Britain's going to say "hmm we're losing ships, ahh fuck it let's let them invade and give up out greatest advantages".

 

[Glenn239]

The RAF over the Channel, intercepts by the RN won't be right off the French coast for the most part, are still going to be under radar control.

Interceptions worked best over Southern England, best of all for London. The further north, the better for the British. As the battle moves into the Channel, it gets more difficult for Fighter Command, such that at the French shore of the Channel, the advantage has moved to the LW. The RAF at the extreme southern end of this Channel battle is probably flying Dunkirk style standing patrols, not doing interceptions. Hipper is correct - the RN wants no part of an all-out daylight Channel Battle, and Sandhurst knew this by writing the LW out of the script. The RN is best to rely on shock tactics to disrupt the invasion formations, accepting a considerably lower attrition rate of invasion forces in night combat, to take the LW Stukas, JU-88's and ME-110's out of the equation.

 

[TDM]

Interceptions worked best over Southern England, best of all for London. The further north, the better for the British. As the battle moves into the Channel, it gets more difficult for Fighter Command, such that at the French shore of the Channel, the advantage has moved to the LW. The RAF at the extreme southern end of this Channel battle is probably flying Dunkirk style standing patrols, not doing interceptions. Hipper is correct - the RN wants no part of an all-out daylight Channel Battle, and Sandhurst knew this by writing the LW out of the script. The RN is best to rely on shock tactics to disrupt the invasion formations, accepting a considerably lower attrition rate of invasion forces in night combat, to take the LW Stukas, JU-88's and ME-110's out of the equation.

Radar cover being better over London than the French side of the channel does not mean "the advantage has moved to the LW" it means the RAF has less of an advantage, and that's Sealion (and sealion threads) in a nut shell any shift no matter how small in the overwhelming and massive advantage in pretty much all aspects has the usual suspects suddenly claiming 'aha we must now tear up all we know, everything has changed, it's game on!'

If nothing else since the LW have to attack or protect known targets (the RN, or flotilla) that makes them rather easier to find and verify. Plus of course there are are going to be a huge number of British eyeballs in the vicinity (not to mention watching those French air fields).

 

[Ian Hathaway]

Radar cover being better over London than the French side of the channel does not mean "the advantage has moved to the LW" it means the RAF has less of an advantage, ...

Actually radar coverage is much better over the French coast than London as RDF was only focused out to sea. But the further the LW travel the better Fighter Command can organise a coherent response. The RAF would not be able to put up the same defence over the Channel as they would over London as the LW would take off, travel and attack before the RAF could respond at anything near maximum or even adequate strength. There's going to be more reliance on standing patrols and keeping fighters airborne to counter Channel attacks.

 

[Carl Schwamberger]

Actually radar coverage is much better over the French coast than London as RDF was only focused out to sea. But the further the LW travel the better Fighter Command can organise a coherent response. The RAF would not be able to put up the same defence over the Channel as they would over London as the LW would take off, travel and attack before the RAF could respond at anything near maximum or even adequate strength. There's going to be more reliance on standing patrols and keeping fighters airborne to counter Channel attacks.

There was also a RAF advantage in the low state of radio discipline in the LW. They apparently did not train well for silent 'form up' of missions. The Brit signal intel could identify the start of a mission by the radio chatter specific to LW air groups getting into formation. RDF located the Chatty Cathys, and counting transmissions indicated size of the group forming up. Im unsure if this was routinely the case, or just a problem with a portion of the LW groups.

 

[TDM]

Actually radar coverage is much better over the French coast than London as RDF was only focused out to sea.

hah fair enough !

But the further the LW travel the better Fighter Command can organise a coherent response. The RAF would not be able to put up the same defence over the Channel as they would over London as the LW would take off, travel and attack before the RAF could respond at anything near maximum or even adequate strength. There's going to be more reliance on standing patrols and keeping fighters airborne to counter Channel attacks.

Thing is where are the LW going, things we already know about (the RN or the Invasion fleet*). and on top of that the BoB lasted months, this is going to be over in days at most so once teh boats are spotted even keeping patrols up for a proportionally significant amount of the relevent time period is more viable than say it was during the BoB.

I take your point about the distance thing but if you end up all operating in a small area i.e the effective operating ares of the invasion flotilla than basically you end to knowing where everyone is all the time and can track in real time far more easily than a battle that was fought for months over all of SE England. Especially as there's going be lots of eyeballs in the area.



*and once that's gone the whole thing is over anyway

 

[Ian Hathaway]

There was also a RAF advantage in the low state of radio discipline in the LW. They apparently did not train well for silent 'form up' of missions. The Brit signal intel could identify the start of a mission by the radio chatter specific to LW air groups getting into formation. RDF located the Chatty Cathys, and counting transmissions indicated size of the group forming up. Im unsure if this was routinely the case, or just a problem with a portion of the LW groups.

It all adds into the mix, RDF, Y Service, Observer Corps, eyeballs in boats and ships, more fighter patrols. The closer the battles are to the French Coast the more difficult it becomes for Fighter Command, not impossible, just more difficult.

 

[Deleted member 94680]

Hipper is correct - the RN wants no part of an all-out daylight Channel Battle, and Sandhurst knew this by writing the LW out of the script.

Do you honestly - and I mean truly, really through your own research - believe that the Royal Navy would idly sit by and let an invasion happen to simply avoid losing ships, or are you saying things like this to get a rise? I mean are you actually so ignorant of the attitudes of the day to believe that the Royal Navy would look at loses in a “Channel Battle” and decide the preservation of cruisers and destroyers is more important than keeping a foreign army off British soil?

 

[Lord Wyclif]

At its narrowest point the channel is 38000yrds wide. Cruisers will smash any thing that moves up to 24,500yrd. The gunners will have a field day and operate only a few miles off shore. It would be like watching someone who was good playing the old ‘space invaders’ game.
They were also expendable along with the R’s, just as the type 21’s in ‘82.
Hurricanes v Stukas only gonna be one winner. Spitfires v 109’s again the spit win wins as the Germans have to travel from France & RAF above Home.
Then there’s Wellingtons and Blenheims bombing the s**t out of the French coast line.
There’s more chance of Ireland putting a man on the moon than there is for a German getting off the beaches other than a POW.

 

[Post]

It all adds into the mix, RDF, Y Service, Observer Corps, eyeballs in boats and ships, more fighter patrols. The closer the battles are to the French Coast the more difficult it becomes for Fighter Command, not impossible, just more difficult.

Also I gather the RAF has a bit of an advantage if they have to defend the RN from the LW. They know where the RN is, what their attack path is, so they can fly CAP, or keep fighters standby, whereas the LW first has to locate the RN, and then get through the CAP and scrambled fighters to the RN to attack it.

 

[fastmongrel]

the RN wants no part of an all-out daylight Channel Battle

Yes the Navy that just a few months ago sent a Battleship up a Norwegian Fjord that at its narrowest is about a mile wide is going to sit on their arses and do nothing.

 

[Mike D]

Would it help at all if the Germans landed on the Isle of Wight first?

 

[Alanith]

Interceptions worked best over Southern England, best of all for London. The further north, the better for the British. As the battle moves into the Channel, it gets more difficult for Fighter Command, such that at the French shore of the Channel, the advantage has moved to the LW. The RAF at the extreme southern end of this Channel battle is probably flying Dunkirk style standing patrols, not doing interceptions. Hipper is correct - the RN wants no part of an all-out daylight Channel Battle, and Sandhurst knew this by writing the LW out of the script. The RN is best to rely on shock tactics to disrupt the invasion formations, accepting a considerably lower attrition rate of invasion forces in night combat, to take the LW Stukas, JU-88's and ME-110's out of the equation.

The Royal navy could lose every single R-class Battleship, every C and D class cruiser, and half its destroyers, and if they stopped the invasion? You know what they would say with those losses?

"By jove, I'd say that's a jolly good trade!"

Except they're not going to lose that many ships. They're going to lose, at best, a cruiser or two and a couple of destroyers. And they'll win a decisive victory that will be celebrated for the next two hundred years.

 

[David Floyd]

Is there any realistic number of destroyers the RN could lose here that would make a meaningful difference in the Battle of the Atlantic? I tend to think not.

 

[ShockTrooper262]

And they'll win a decisive victory that will be celebrated for the next two hundred years.

If HMS Nelson is there, it'll be for three hundred years.

The only way the Germans pull if off is if the Brit 'Ai' is turned off, and even then I think they'd lose

 

[Ian Hathaway]

Spitfires v 109’s again the spit win wins as the Germans have to travel from France & RAF above Home.

St. Omer to mid-Channel = 65km
RAF Gravesend to mid-Channel = 90km
RAF Hornchurch to mid-Channel = 110km

Just pointing out some of the difficulties that Fighter Command would have to face.

 

[Ian Hathaway]

Also I gather the RAF has a bit of an advantage if they have to defend the RN from the LW. They know where the RN is, what their attack path is, so they can fly CAP, or keep fighters standby, whereas the LW first has to locate the RN, and then get through the CAP and scrambled fighters to the RN to attack it.

The Germans had pretty effective land based radar that could detect surface ships. In all likelihood they'll know the RN is approaching.

 

[marathag]

Yes the Navy that just a few months ago sent a Battleship up a Norwegian Fjord that at its narrowest is about a mile wide is going to sit on their arses and do nothing.

And rammed a 18,000 ton heavy cruiser with a 1500 ton Destroyer

 

[fastmongrel]

Would it help at all if the Germans landed on the Isle of Wight first?

In retaliation Britain could invade the Freisian Islands.

 

[Coulsdon Eagle]

The Germans had pretty effective land based radar that could detect surface ships. In all likelihood they'll know the RN is approaching.

Well, of course they will. The RN is heading for one juicy target [or several hundred juicy targets]. Where else would they be heading? Just as Fighter Command could fly CAP over the Fleet, the Luftwaffe just needs to keep reconnaissance aircraft over a small number of approaches to the beachheads with their Stuka force on high alert. Mind you, sitting on their arses in France will mean they aren't bombing the coastal defenses.

In the end, everyone will be concentrated into a small strip of sky over the Channel and southern England.