Operation Sea Lion (1974 Sandhurst Wargame)

[DaveBC]

No drama. He was, But he was promoted

Well at least I got the Peter principle part right then.

 

[soothsayer]

Well at least I got the Peter principle part right then.

As they said when I was in the army..

Everyone gets promoted to their level of incompetence!!

 

[Grand Admiral Thrawn]

Maybe with a different commander??

Merely giving a different commander is not enough. If his was the only army in the area, you might be right, but since the UK has division motorized, as well as working railroads, he would either be sacked or rendered irrelevant as the armies on his flanks press the attack. Sedan in 1870 and 1940 worked since the French army was alone; conversely, the French and BEF in 1914 were able to survive tactical mistakes since they could support each other. And even if this guy was in charge of the entire British Army it would not be enough, as the RN and RAF still attack the KM ships, turning Sealion into a Stalingrad or Kerch. Other examples of the (un)inportance of individual commanders is at D-Day, 1 of the US generals was despondent and wanted to order a withdrawal, but his subordinates talked him out of it. Even if he had withdrawn, 3 beaches would still be held on June 7. The Russians prob would not have won the Battle of Tannenburg but since the 2 armies could not support each other, they were destroyed in detail. Now, if Burnside was ISOT to be generalissimo of the British forces, you'd have a real chance of victory, but not while even average leaders are present.

 

[DaveBC]

As they said when I was in the army..

Everyone gets promoted to their level of incompetence!!

Yep, that's the one.

Apparently even a world war has nothing against bureaucratic inertia.

 

[RodentRevolution]

Apparently even a world war has nothing against bureaucratic inertia.

Talking of which s-booten, I don't believe we moved swiftly on, so

The question would be, how effective they were as convoys escorts as that is the role they will be called on to play in Seelöwe?

Now I do know they were employed on occasions as escorts for German coastal convoys. How well did convoys perform when thus escorted. Anyone know? Because a lot of the discussion above is irrelevant if the landing forces cannot concentrate more than a two company composite battalion on the beaches. Absolute numbers will not matter if the British are somewhat organised and the Germans are not.

 

[steamboy]

And as an added bonus, the British troops won't be sea sick.

 

[Ian Hathaway]

Maybe so, but going back to USM discussion in 2006 has at a minimum light cruisers and DDs as part of the forces available in the channel. For example, this post from 2006:

https://www.alternatehistory.com/fo...-sealion-have-worked.40410/page-6#post-708028



However the poster who I originally replied to said no capital ships were planned to be used in the Channel which is not supported by facts. There was a BB there and multiple CLs, DDs and other vessels that would be in easy range to immediately intercept any invasion attempt. If necessary, the RN could have sent the other vessels detailed for anti invasion activities such as this group which was moved on 13 Sep 40 to Rosyth:



By my count 2BBs & 1BC alone were ready to stop an invasion beyond what was closer to the Channel. So previous posters citations were flawed at best.

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.

 

[nbcman]

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.

Why would the RN wait until they see the German barges attempting to cross the channel? The barges would come from the ports where they were assembled - such as from Antwerp. A 4 kt barge leaving Antwerp would take more than a day to get to Dover - which doesn't take into consideration time to have the barge armada form up, maneuver in a somewhat organized force through the channel while dodging sundry threats, and to unload on the shore. There was plenty of time for RN forces to move closer when and if the Germans started to surge their invasion forces out.

EDIT: Especially since the Germans were going to start loading operations DAYS in advance of the invasion - up to 9 days in advance of the invasion date (S-tag) for the heavy equipment in Antwerp. So there would be many hours of notice for RN forces to get closer to interdict the invasion attempt.

 

[steamboy]

Nbcman beat me to it but he's right, the German convoy would be VERY slow and whilst it may only be a few dozen miles at the most at the narrowest point, the Channel's still broad where it counts. The Germans could 'rush' a part of the convoy across but I assume that they'd not want to have landing forces arriving at different times. So would have to wait for forces from say Antwerp to reach position for the attack so the landings are all made at roughly the same time. So this means that its gonna take a bloody long time to get the barges out, formed up and then have them all come across at the same time to strike at hopefully the same time. This gives the RN ships more than enough time to steam down or around.

 

[Cryhavoc101]

Thanks

I see the “60k” of SMGs only arrive by August. Arrive! They still have to be depacked, degrease, train instructors and issue.

400M is not a lot. 12M is been used a week. Mostly RAF. 50M is mainly special rounds for RAF.

A single inf battalion with 12 rifle plts/ 36 Brens needs ~36000 rds just to fill Bren mags. 0.1M per division.

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.

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

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.

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

 

[TDM]

Doubt it, those barges are so shallow drauft they'd probably go under them for the most part unless the RN fiddled with the depth keeping bits and bobs on the DD's torps prior to sailing. The Torps would still be useful against larger vessels though like any German DD's.

Yep, given how much RN and auxiliary stuff there might be about Torpedoes might be more a liability than benefit.

Sealion required about 2,000 tons per day minimum, whether over the beach, via port, or air transport. The best over-the-beach they had were the 50 Siebel Ferries, (about 3,000 to 5,000 tons beach capacity) After that, it was a mixed bag of MB's, transports (offshore offloading), or barges (which would have a higher rate of accidents while landing).

Only these thing are trying to resupply through the RN & RAF and Auxiliary right? Every time one gets sunk in any leg of the back and forth trip that's one less available to continue the supply run. On top of these you also trying to land the 2nd wave who will nee those transports (if there are any left for them)

Your estimate is more than fair to the Germans for a defensive posture. 1,000 bombers and JU-52's should be able to sustain 100 tons deliveries per day. 50 Siebel ferries - with another 25 to 50 being built per month - should be able to do over 1,000 tons, perhaps even 2,000 tons, per day. 500-1,000 MB's should be able to do over 1,000 tons per day. 2,000 barges with 200 tons capacity each should be able to do over 1,000 tons per day. A

If they're not sunk or shot down, miss their drops, are actually there at all what with the issues the LW are having with air crew availability and spare parts by Sep40

It's not the barge deck guns that are driving off the RN. It's the 6,000 Luftwaffe sorties in an all-out Channel air sea battle.

What no RAF again? So no not Air vs. Sea but Air vs. Air & Sea

Also where has this 6,000 sorties figure come from, and over what time scale?

During the BoB in the period 10th July - 31st 0ct (113 days) the LW ran 67k sorties including all aircraft in all mission types (figs from download at bottom of this story) or approx 600 per day over the entire period. Obviously there were lulls and periods of heightened activity during that period*. However you talking about doing this in mid / late Sep which is after the attrition of the BoB has begun to takes it toll. You are also talking about doing this at the same time as landing Paratroopers and all that air supply drops you mentioned above?


*but you'll see some natural patterns emerge. Only once does the LW string two days of more than 1000 sorties together in a row, and after a heavy few days there's often a light few days (naturally enough since they need recovery time). Looking quickly by eye I think the busiest 7 day period is 30th Aug - 5th Sep with 5691 sorties

If the initial breakout fails and the British do not ask for peace, then well into 1941.

How are what ever bits of the first wave that makes it ashore going to hold out for months?

The British army was also not adequately trained or lead at this time in many units. It also had serious conflicts in doctrine between schools of thought on anti-invasion work.

Maybe (although I think you are overstating) but since all they're doing is sweeping under equipped and under supplied infantry back into the sea, they don't need to be.

The Germans had 120 divisions in France. Maybe 40 would be needed in Spain or the Med. How many replacements do you think 9 divisions in Britain would need per day?

How are they going to get there?

 

[Alanith]

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.

Well it's a good thing that the Invasion convoy will take upwards of 48 hours to get to the landing Area. Revenge has enough time to sail, get to the landing area, realize they forgot to bring enough spare ammunition, head back, reload, sail back to the landing area, and still intercept the barge armada.

 

[Cryhavoc101]

Plymouth to Portsmouth = 133 NM

Rosyth to Dover = 400 NM

Portsmouth Dover = 106 NM

 

[TDM]

Well it's a good thing that the Invasion convoy will take upwards of 48 hours to get to the landing Area. Revenge has enough time to sail, get to the landing area, realize they forgot to bring enough spare ammunition, head back, reload, sail back to the landing area, and still intercept the barge armada.

Yep, on top of this, while the actual transit time might be 48 hours (if they catch the tides right, miss one and they'll add more time). There are a few extra time sinks that will add in before the entire first wave is ashore:

1). Embarkation (getting 75k guys aboard such an ad-hoc collection of vessel isn't quick), these ports are being watched not just by the RAF, but several can be seen from the British shore! Not to mention local Resistance cells, naval and auxiliary patrols etc, etc

2). Forming up, now they're not all going to go across in one big clump, but this plan did involve many of them being daisy chained together in combinations of more sea worthy boats, powered barges and un-powered barges (and pontoons of horses IIRC), and travelling in groups to avoid arriving piece meal. That is going to take time to set up and of course you're doing this in the channel's tides and currents. It also adds transit time. Anyone who's ever steered a car in a tow situation (in either position) knows how much more complicated this is than just driving a car. Everything gets harder and failure states are great not forgetting that even not daisy chained together these barges weather under powered of un-powered are not fit for these waters.

3). Having got to a position off the destination beeches, then getting into a position to land. Even for the barges this could only be done at certain tide positions. Even worse for the un-powered barges this would involve them being pulled along parallel to the beaches, then released and then making a 90 deg turn into the beech using their inertia and the incoming high tide to land. Yes that's about as bad as it sounds. They did an unladen small scale trial run of this on a home beach where they simply went out and tried to come back in on the same day. Therefore knowing the weather, tides, currents and beach conditions. So also not having done the cross channel journey (with or without the RAF/RN), or relying on a 3-4 day weather forecast . Result = half the barges made it ashore the rest floated away and had to be recovered, apparently this was deemed a "success".

4). Disembarking / unloading. As per embarkation 75k men and what equipment they have brought with them doesn't happen quickly. But when embarking they at least had the port infrastructure, here it's all going on to the shingle. The larger boats that can't directly land on the beaches they will have to stand off and unload via smaller boats (or just chuck stuff over board and get it manhandled ashore, if they have a shallow enough draft to at least get close enough to do that). Of course during all this time the tides and currents are changing so that will have to be taken into account with all the above.

finally even once unloaded

5). getting the barges back off the beaches and underway again, those daisy chains will have to put back into formation. You need high tide to float them off the shingle initially, but your then fighting that tide in order to pull way from the beech which when manoeuvring un-powered or under-powered barges won't be easy, you will likely need the tide going out again.

What you really don't want is having gone to all the trouble of finding and landing and disembarking on your beach, is for the RN to turn up sink/disrupt or bottle up all the barges & boats etc while 5 is happening, then shell your beachhead. (But then I think a lot of things the Germans don't want to happen will be happening in this little adventure!)

 

[Alanith]

And while the RN may SAY it wouldn't have committed the heavier ships, I suspect in the heat of the moment... well let's be honest, any commander who holds battleships back is going to be acutely aware that if he does so and the German's manage to land, he'll be facing a board of inquiry at the very least, if not a full court martial.

 

[TDM]

And while the RN may SAY it wouldn't have committed the heavier ships, I suspect in the heat of the moment... well let's be honest, any commander who holds battleships back is going to be acutely aware that if he does so and the German's manage to land, he'll be facing a board of inquiry at the very least, if not a full court martial.

Yep although I think the deciding factor will be how much of the KM comes out to play. If the KM sacrificially decides to commit a significant amount of what it has left from the Baltic / North Sea Harbours to hobble itself to a 2-4kn flotilla in the channel under the RN'S noses to get as much of the first wave across as possible the RN capital ships will take the opportunity to wipe it out.

 

[Zincwarrior]

Yep although I think the deciding factor will be how much of the KM comes out to play. If the KM sacrificially decides to commit a significant amount of what it has left from the Baltic / North Sea Harbours to hobble itself to a 2-4kn flotilla in the channel under the RN'S noses to get as much of the first wave across as possible the RN capital ships will take the opportunity to wipe it out.

Indeed. I would envision the BBs would be used to intercept any material KM units, in holding positions north and south of the prime beaches, where they would have more meneuvering room. Additionally they could be used in these locations to intercept any German convoys of actual ships (barges and eboats too small to be worth attacking by a BB at this time).

If the barge flotilla starts they can always move in and start obliterating the barge formations trying to land, and punishing the beachheads. Inversely they could stand off and start punishing the harbors of the second wave, cutting off support and turning the beachheads into defacto POW camps.

 

[DaveB]

And as an added bonus, the British troops won't be sea sick.

To be fair, I’ve been severely seasick twice (courtesy of the MV Scillonian, aka the Great White Sickbucket), and on both occasions I felt almost fully recovered after taking a few paces on land, and even managed to drive 300 miles home on the second occasion, starting as soon as we had walked to the car park.

 

[RodentRevolution]

For all the talk of battleships what was attached to Sealion that could not be annihilated by a County or Town class cruiser?

 

[Deleted member 94680]

Also, when talking of the shortest crossings over the Channel, you must remember these are also the most obvious lanes for the convoy to use. Therefore they will be the most closely watched ones. Therefore, the RN’s reaction times will be the shortest for these lanes. The longer “less obvious” lanes will have longer reaction times, but the convoy will take longer to traverse these lanes, so the RN can afford to take longer to reach them.