Challenge - Make Sealion Possible !

Grey Wolf · Apr 14, 2007

Challenge - Make Sealion Possible !

I don't mean a hurricaine to sweep away the British fleet, but what institutional and incremental changes to Nazi Germany in the years preceding 1940 could have come together to allow for a feasible assault on the British Isles ? An obvious example, what would have given the German army an interest in amphibious assault ?

These changes must not of course remove factors necessary for the successes of Nazi foreign policy to 1939 and for the victories of the Blitzkrieg in Poland, Scandinavia, the Low Countries and France. If it did so, it would remove the politico-military possibility of Sealion, even if leaving it a practical one.

The debate can be a wide-ranging one but must have the constraints that a successful Sealion (or without Jodl's interference we can call it just 'Lion') is achieved by the Nazis. To change the entire political history of the 1930s or the men at the top undermines the point of the challenge. The changes should be below the grand strategy and national political level.

That does not mean that senior Nazis cannot be eliminated. I would argue in another thread that a successful Barbarossa might have been possible without Bormann, so removing him in a convincing fashion, or preventing him having the negative impact he did, makes sense. Here, perhaps the removal of Goering from the picture might aid us, but how is it accomplished so that it doesn't undermine the success of the Blitzkrieg with regard to dive bombers and combined operations ? And how is it slotted in so it does not upset the political scene ?

Given the practicalities of ship-building capability and the desire and NEED for Nazi prestige in naval matters, I cannot see much alternative to the capital ship programme as occurred. To have not built the pocket battleships or to have not laid down Bismarck and Tirpitz would have had a major symbolic impact that does not equate with keeping the grand strategy level stable. If we convincingly get rid of the Z Plan does it make any difference ? It was a future vision, an aim that was barely started. If freeing up materiele gathered for the laying down of the first H-class battleship means something can usefully be done with it in the time, then good. More destroyers, or cruisers perhaps ? But on a practical level avoiding the disaster of Narvik would give more destroyers and might be more easily attained. How key was Raeder ad would his disgrace have achieved any better results ? (I have an odd note he was gay, is this so ?)

Could we look at areas the Nazis refused to go in and find a possibility of using them ? Poison gas for example. It is always assumed Hitler's personal experience of this, plus his fears about Allied use of it in reprisals made it a definite 'no' but with the Nazis IS there such a thing ? During the war they MADE new gases for combat use, even did so in bulk and even ordered gas-masks for soldiers, but never used it. What potential change could bring it into use at a decisive moment, and would it be a tactical or a strategic outcome ?

All German agents in Great Britain were blown or turned. Canaris and the Abwehr did not realise this, but even if they had their attempts to infiltrate new agents always failed anyway. Is there a way to have some of the original ones escape detection ? If not, would the knowledge that Snow, Garbo etc were double-agents have had any positive effect if that knowledge could have been delivered into German hands ?

I'm looking for PODs deeper than would be obtained by, for instance :-
- Blucher is not sunk in Oslo Fjord
- German u-boat torpedoes work better off Norway and they sink several larger British warships
- Narvik is avoided and the German destroyers survive
- The cruiser carrying the Norwegian royals and gold is sunk (didn't a German surface force come close to it without realising it ?)
- The Dutch royal family is captured as per the air-drop plan
- There is no halt at Dunkirk and the BEF cannot be evacuated (IMHO this has to come at the cost of some serious German losses in consequences of pushing the attack at their limits)
- The Luftwaffe go after the radar and repeater stations, and no bombers accidentally bomb London leading to a revenge attack on Berlin

The above seems the best 1940 ATL in realistic terms. It keeps more of the Kriegsmarine intact. It deprives Britain both of manpower and the morale boost of Dunkirk. It gives the Luftwaffe theatre superiority. BUT DOES IT GET THE WEHRMACHT OVER THE CHANNEL ?

My problem with this is that the Channel is basically the last redoubt and whilst the Germans might trust in airpower or minefields or those naval ships they do have (even if substantially more than survived in OTL), the Royal Navy COULD bring everything to bear. It would be a risk, but the only factor preventing its being committed to battle would be the defeatist one of keeping a bargaining counter in case the worst happens.

Given that, do you commit the fleet to a risky battle that can prevent an invasion in force or do you err on the side of caution ? It seems illogical to do the latter. Even massive losses keeps the UK alive if it destroys the invasion fleet. It seems to me (very IMHO I know) that it would be risked. Given Halder's comment about the German army planning to cross the Channel slower than Caesar did (!), it seems likely it would win. Even if broken, a victory prevents a repeat and the fleet can be rebuilt with ships currently on the slips or fitting out.

So, the changes have to go deeper. Without Goering can we get long-range bombers and a naval air arm under Kriegsmarine control, without compromising Blitzkrieg, and even if we do does it make any difference ? Who would take over from Goering - Udet, Jeschonnek, Milch ? IMHO its disastrous, stable or good in that order. But would it make a difference within the necessary timescale ?

Can we find a way to get some faster landing craft in German hands - and if so, why and how ?

I would be very interested in an in-depth discussion of this hot 'curate's egg' potato. If tactical 1940 possibilities are indeed insufficient to achieve success, what deeper structural tweaks and turns can we make to have (Sea)Lion an assault with a good chance of success (say 50-50 or better) ?

Best Regards
Grey Wolf

King Thomas · Apr 14, 2007

You would have to make Hitler desire conquest of the West as much as he desired conquest of the East in OTL. The Western conquests were to keep trouble off his back-what he deeply desired was to rule Russia,and you don't need a huge navy for that. You could have Hitler wounded by the British in WW1 and he develops a deep hatred for them, maybe as deep a hatred as his OTL one of Jewish people.

stevep · Apr 14, 2007

King Thomas said:
You would have to make Hitler desire conquest of the West as much as he desired conquest of the East in OTL. The Western conquests were to keep trouble off his back-what he deeply desired was to rule Russia,and you don't need a huge navy for that. You could have Hitler wounded by the British in WW1 and he develops a deep hatred for them, maybe as deep a hatred as his OTL one of Jewish people.

KT

Not sure if it was against Britain but Hitler did serve on the western front in WWI and was wounded in that he was blinded for a while by gas.

Steve

Grimm Reaper · Apr 14, 2007

Well, when Raeder asked about the prospects of the upcoming attack on the west he was advised, by one of the top panzer commanders no less, that it would probably take another six months just to break through the Anglo-French lines to the Channel.

If Raeder gets different advice the Germans can at least have a few months advanced on producing landing craft and escorts.

The problem with avoiding Narvik is the risk of Germany being obliged to keep a few divisions and substantial air power in Norway, which doesn't help any invasions of England.

Glen · Apr 14, 2007

I think you need three separate changes in the timeline for Sealion to have any chance of success.

1) Germany must early on start work developing landing craft for amphibious assaults.
2) The BEF fail to be evacuated at Dunkirk, and are instead forced to surrender to the Germans.
3) The Luftwaffe keep their focus on attacking British air assets and do not switch to city bombing.

If Germany can develop a way to rapidly get on shore, if they can seriously hinder British preparedness by no evacuation at Dunkirk, and they can gain air dominance over the Channel and coast, thus allowing them to counter the British navy with their unopposed land-based airforce then there is a chance for Sealion to get a foothold in Britain.

drakensis · Apr 14, 2007

My best guess is that to make Sealion work it would have had to be planned seriously and several years spent working out what was needed and then developing those requirements.

Strategically, the Germans would have needed to take effective control of the Channel or part of the North Sea (and the air above) for a couple of days. Conceivably, flooding the invasion area with submarines, torpedo bombers and fighters could have battered the Royal Navy and Royal Air Force to the point that they were ineffectual for a few days. But the chances of doing so to the point that they wouldn't be back to hit the supply lines are slim so there would be a running battle.

If there was an invasion fleet in the West Schelde then they would have to cross 250km to reach Southend. Assuming a minimum of bumbling around, this would still take something like seventeen hours (based on an LST having a top speed around 22kmh and a 50% bugger factor) which would require setting out around noon the previous day in order to attack at dawn, so it would be absolutely critical to prevent anyone from noticing the departure. So two days of control over the region between the Straits of Dover and 52 degrees north would be the absolute minimum required.

But if they could get a couple of Panzer Divisions (plus supplies) off the beaches then it is reasonable to think that they could have reached London from Southend in two days - that would be consistent with rates of movement during the Battle of France. While resistance would hardly have collapsed at this point, the government would have been seriously weakened.

history_fanatic · Apr 14, 2007

O.k this is completely leaving out troop levels and supply lines, but what about a revised invasion that not only crosses the Channel but also crosses the North Sea from Trondheim, Alesund, Floro, or Bergen in Norway and lands in Scotland around Aberdeen and Inverness. Yes they would be on alert, giving that the Channel front would be semi-diversionary, but they would be expecting the usual blunt tactics, and single minded determination from Hitler. One problem is that this would weaken the German push at the Channel by siphoning men away to Norway but this can be rectified by some German strong-arming of the Italians.
Another possibility could be that General Francisco Franco takes Germany up on offers of territory and joins the war. Spain could possibly take over some occupation duties in France thus freeing up German troops, let alone a Spanish push on Gibraltar thus cutting off English access to the Mediterranean, causing logistic problems for the English down the road.
Maybe Germany could persue a more active approach with USSR and give them the Baltic rights that they want in exchange for use of Soviet planes or Soviet ships, but then Hitler would have to overcome his deeprooted hatred of communism for a while, making this highly unlikely.

The Dean · Apr 14, 2007

One way to make this work would be a strike to kill/capture the royals by air dropped special forces immediately before the invasion goes in. If they used enough personnel they could take out as much of Whitehall as possible. Buckingham Palace is only a few hundred yards from Downing Street.

Peter Cowan · Apr 14, 2007

I think there are too many "what ifs". One or two, three at the outside, maybe, but when you go over that number all you do is show how the original premise is so flawed that it could not happen.

For what it is worth, my opinion is that the only way the Germans could have knocked the British out of the war in 1940 was not to have Churchill as Premier. Either Chamberlain survives - the Commons vote delayed beyond May 10th - a leadership change may not happen in such circumstances or Halifax becomes PM.

Electric Monk · Apr 14, 2007

To save time (most of it from this thread, using the two most pro-theoretical Sealion assuming some sort of POD viewpoints who also use reason

Steffen Redbeard said:
Well, a lot of things will NOT be a problem for the Germans:

The British Army
Hardly had any heavy equipment and only little training + deficient doctrines. Brooke was very concerned about leadership level at Division and above.

Gathering the vessels for the invasion fleet
To me it appears like the KM intentionally obstructed the planning, and anyway had very little imagination. The ferry fleet in Denmark alone, which was under German control from april 1940, would have sufficed to land and supply a 10 Division invasion force.

Crossing the channel
People do it every day, some even swim across.

Logistics
Prefabricated ramps for the ferries, scutling of old ships as breakwaters and some engineers connecting the ramp with the roadnet would have provided excellent logistics "over the beach". One "standard" railway/car ferry will carry 100+ 3 ton trucks which is equivalent to the daily need of a Division on offensive stance. With 30 minuttes interval between the ferries you have plenty of time to unload (can be done in 5 minuttes, another 10 to load empty trucks for the returntrip), and even with only one "beach-ramp" in function you will need it to operate only three hours each day to supply ten Divisions. That makes it easier to adapt to the tide.

Defending the bridgehead
The British Army will not be able to launch any large co-ordinated counter attack but the RAF is likely to throw everything they have. But if taking the same AA force that defended the bridge over the Meuse at Gaullier in May (six AA battalions with 300 guns total) the RAF is unlikely to gain results, but will take heavy losses. The Bombercommand operational total is hardly above 200 planes (IIRC 150).

BUT ONE BIG PROBLEM REMAINS...and that is gaining and keeping the seacontrol over the crossing and landing zone. And that seacontrol is simply necessary - no matter the rest.

The KM was far from having the strength for that, and a prewar PoD making a bigger/earlier German naval programme will have UK say STOP to Herr Hitler years before. It is tempting to deploy the Italian Navy for the invasion, but that will require some disastrous results for the British in the Med. in June/July and a Spainsh entry into the war and taking Gibraltar. But even with the combined German/Italian/Spanish navy vs. a RN with the Med. Fleet wiped out I'm not sure it is enough.

The most important PoD probably would have to be in the Luftwaffe. In OTL by 1940 it had a very limited anti-ship capacity, stemming from lack of both suitable weapons and tactics. Getting that in time probably requires another C-in-C than Göring (Bluetooth's formidable TL comes to mind), but probably could be carried through without awakening the allies too much. Basically it requires a significant part of the medium bombers to be trained for torpedoattack and the Stukas being supplied with heavy AP bombs (and trained for sea attack). Plus not at least Luftwaffe and KM training co-operation. My guess is that about 1/3 (300-400) of the LW medium bombers will have to be able to perform torpedoattack to be sure. Not a small effort but possible. The biggest problem is that it requires the Germans seriously planning to go to war with UK, and apparently the Germans didn't seriously plan anything - not even Blitzkrieg!

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It is often said that Sealion could never suceed because the Germans had no clue about amphibious operations. The thing about the clue might be right, but I strongly disagree that this should prevent Sealion from succeeding. The Germans considdered Sealion an extended rivercrossing and basically I think this was the right approach - if being German. Anglo-Saxons would of course never with their tail heavy organisation have done it that way, but German army units traveled light and with 10 Divisions across I doubt there would be much the British could do.

That the Germans didn't have the liftcapacity to cross the Channel is simply rubbish. A German Division on the attack would need in the region of 250 tons of supplys a day, and I'll claim that the Danish railway/car ferries, which were under German control after april 1940, could alone land and supply at least 10 Divisions. Not over the beaches of course, but from a conquerred port and with some prefab ramps in place. All in all not impossible engineering jobs.

Where the impossible thing comes in is in achieving the necessary seacontrol over the Channel area. By 1940 neither the Kriegsmarine nor the Luftwaffe were in any state near able to secure that. Had the entire Luftwaffe prewar been trained in seatarget attacks (i.e. torpedo attacks) and incl. cooperation with the Kriegsmarine, then they might perhaps just have had a chance, but they didn't start training for that until much later. By 1940 they mainly would have send level bombers, which were about useless against moving targets. Stukas were OK against destroyers, but against a battleship with armoured decks a 1940 Stuka would not have made much impression. Next there only was couple of hundred operational Stukas in mid 1940, I doubt that would suffice against the main force of the RN.

To me it seems like Kriegsmarine had realised the impossibility of the sea control part and used any trick to avoid the humiliation of becoming the scapegoat of a failed Sealion, incl. wildly exagerating the need for tonnage and not showing much imagination in where to get it.

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IF the Germans can secure airsuperiority and seacontrol over the Channel, and that is a very big IF, then I think the only thing that could stop them would be looking at the operations like Anglo-Saxons of 1944 would. That doesn't say that the Anglo-Saxon way was wrong, it wasn't for Anglo-Saxons, but that just wasn't the way the Germans fought. From a German perspective looking at it like an extended river crossing IMO actually makes sense. But letting an Anglo-Saxon landing operation against a heavily fortified German occupied coast in 1944 set the agenda for a 1940 German landing in a vaguely defended England is indeed a very troublesome method.

In second half of 1940 the British Army simply wasn't in a state fit to fight an opponent like the 1940 Wehrmacht. And secret weapons at Ramgate or whatever will not make the difference (secret weapons rarely do). Please read Alanbrookes unedited war diary (also interesting reading about Churchill). Alanbrooke was resonsible for the homedefences after the campaign in France, and he indeed was very worried about the condition of the British Army. Not only the lack of heavy equipment but even more the incompetent level of leadership at especially Divisional level. I doubt if the British in late summer of 1940 would be capable of operating a Divisional size force! Even a 30.000 men German infantry force landed in motorboats and yachts (like the other way Dunkerque evacuation) would have been a too big mouthful for the 1940 British Army!

But apart from the Kriegsmarine obviously working with other criterias of success (or with incredible incompetence) the Germans probably also had a problem with intelligence. From their judgement of how many troops they needed to land it appears like they wildly overevaluated the British Army.

But the main point is that the problems of Sealion doesn't exist in crossing the Channel or landing in England, but in achieving and maintaining control over the crossing and landing zone. And PoD's to get Germany a stronger naval strength are hard to find, as any such attempts are difficult to conceal and will trigger British antagonism(rearmament) earlier - and that's just about the worst that could happen to Hitler.

Regards

Steffen Redbeard

DMA said:
About the only way Sealion could have succeeded was if the Germans had some clue as how to conduct an decent amphibious action. Norway was pure luck. The invasion of Norway, if conducted against a determined & ready enemy, like the UK, would be doomed to failure. And considering the main tactic of the Kriegsmarine was to simply sail into British ports & take them intacted would have been a thorough disaster as well. Then there's the problem with neutralising the RAF, not to mention the RN. Furthermore, the way the UK Army was positioned in readiness for an invasion, would have ensured that the Germans would have lost at least 8 divisions for nothing.

At lot of this last part, the army, is important & is often forgotten in a lot of discussion over Sealion. The Germans, without doubt, had control of the air around August-September 1940 over the Channel I think it's fair to say. The naval control is important, but although the RN had the surface ships, they lacked U-Boats &, needless to say, airpower where it mattered. In all likelihood, the Germans probably would make it to the beaches. Alas, their plans were hopeless. Attacking Dover would have been suicide. Likewise, their attack to the south towards Folkestone & Hythe would have been no better. Don't forget the Germans couldn't bring much artillery or even tanks with them. Thus the initial attacks would be mostly conducted by light infantry for all intents & purposes. Now all along the coast in this region were the Martello Towers, not to mention cliffs everywhere. The Germans would have had to deal with the towers & the geography all of which favours the defender. Meanwhile the British move forward their units to trap the Germans on the beaches. Whether the Germans invade at Dover &/or Folkestone-Hythe, their forces would be hence trapped with no where to go & no one to help them.

So where do the Germans invade? Simply they do a Normandy & land to the south of Ramsgate. There are plenty of beaches, plus it's some distance from Dover. So the Germans can establish themselves some miles from the expected invasion area where the British thought the Germans would attack. This hence gives the Germans time to prepare for British counter-attacks.

But before all that takes place, there's the invasion itself. First you'd land your airbourne units around the beaches at Ramsgate & create a defence perimeter, whilst the first wave comes ashore. We're talking about 2 airbourne & 3 infantry divisions at this point. The next wave (or two) sees an additional 2 infantry & 1 panzer division arrive. By dusk, not only do you have a large force ashore safe & sound, but Ramsgate is also taken. This is important because Ramsgate has a port so the Germans can commence bringing in the next waves which have all the heavy equipment.

After a few days of building up the German forces, a feint attack of 3 divisions heads for Canterbury, whilst the main attack of 2 panzer, 5 infantry & 1 mountain divsion drives for Dover. The all important port is taken from the rear making it's defences more or less useless in repulsing the real German attack. Once Dover is taken & open for shipping, well the Battle of Britain is more or less over barr the shouting. But the German plans were nothing like this, so they lose big time with 8 divisions slaughtered instead.

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The RN would be a very serious threat to the invasion. But, because the Germans are invading ramsgate, the Portsmouth "squadron" is at some distance in order to intervene. They'd have to chance the Channel which would be mined so heavily a person could possibly walk from Calais to Dover on the mines (if mad enough to try). To the north of Ramsgate, however, we'd expect naval action. So I wouldn't be surprised to see the RN ships from Rosyth & Scapa Flow come together & attack. Waiting for them would be at least Gneisenau, Scharnhorst, Admiral Scheer, Deutschland (or Luztow depending upon the date) & whatever else the Kriegsmarine could sortie. The German ships would be backed up by the Luftwaffe. The result I'd say would be a draw, but that's all the Germans need as long as the troop & supply ships continue to get through. Within a few days after the naval battle, the Germans are firmly established around Ramsgate & could commence their land campaign. I'd give the British about a month of hard resistence.

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Your missing one vital point in your analysis of the RN. It isn't a united force. Half of the Home Fleet is located around Scapa Flow. The other part is located around Portsmouth. Other ships are scattered around other UK ports. This makes a united RN effort impossible. Any move from Portsmouth to Dover will receive serious damage from mines. The Luftwaffe can help too, but it's the mines which will cause hassles. Remember what happened to Gneisenau & Scharnhorst at the end of Operation Cerebus. I see the same result for any RN force coming from Portsmouth thus making them combat ineffective. This is besides the fact that the Germans are at Ramsgate & not Dover.

Mind you, as I've said before, this entire AH scenario depends on whether the Germans go solely for Ramsgate & not the area from Dover to Hythe. If it's the latter, I have no arguement with Sealion being a thorough defeat for Germany. But if they go for Ramsgate, the Germans have a chance. Having said that, if by some miracle the RN has a successful victory over the Kriegmaine somewhere north of Ramsgate, then I'd agree that the German Invasion army is in serious trouble. But I can't see a RN victory under the circumstances which I've outlined.
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I'll start by asking a simple question "How can the RN concentrate?" That's the main problem for the RN. As I've said before, the OTL RN is split up & it's impossible for it to concentrate in overwhelming numbers. I'm talking the OTL situation here in July-Sept 1940.

As such, there's basically three groups of the RN during this period:

Group 1 -The Home Fleet is based mostly at Scarpa Flow with 2 battleships & 3 battle cruisers. Other ships of the Home Fleet are scattered around the ports of the UK including 1 battleship & an aircraft carrier or two.

Group 2 - H Force & the Mediterranean fleet. I'd expect these ships to arrive after the initital invasion, but from the south & away from the Home Fleet.

Group 3 - These are ships on convoy duty. You can forget about most of them being involved in any action against the Kriegmaine.

So the only real reaction, which the RN could have done in the OTL, is a drive from Scarpa Flow with the Home Fleet. You can probably add one more RN battleship to the Home Fleet.

Meanwhile the Kriegmaine haven't merely been waiting around just to get sunk. I looked up a few figures on the Bismarck. She, in the OTL, was ready for action from late August 1940. So you can add her to the list of ships waiting in the North Sea for the RN. Added to the Bismarck would also be Schlesien. Now Schlesien may indeed be close to useless, but she does have 11 inch guns. So that's 6 German capital ships against 6 RN ones. And at least four of the RN ships are WWI vintage; only one German ship is from this period - the rest are modern. Now the RN ships may have bigger guns, but 3 of them are battlecruisers - the Hood, Repulse & Renown. Their deck armour is hopeless when compared to a battleship. So, in a way, the two fleets more or less equal each other. As I keep saying, the intervention of the Luftwaffe merely tips the balance towards the Germans, but there isn't any great victory for either side. But the RN must win, whilst the Germans only need a draw.

Now after this re-run of Jutland, H Force comes charging into the Channel in true Balaclava style. As it would happen, they'll be too late to stop the invasion. They'll also be too late to stop the early German convoys. But that's not the problem, it's getting through the Channel & then into the convoy lanes heading to Ramsgate. All I can see, for the ships of H-Force, is they are either sunk or put out of commission with serious damage. The survivors have to withdraw with no effect whatsoever on the German invasion plans.

But this all depends upon the Germans completely changing their plans for Sealion, which I can't see happening. So like everyone else I agree, if Germany conducted Sealion as planned, the German army would be slaughted. Half wouldn't have even made it to the beaches, but they'd be bombed by the RAF or intercepted by the RN, whilst those Germans who do reach the beaches won't last much longer than the others.

Alcuin · Apr 14, 2007

Glen said:
I think you need three separate changes in the timeline for Sealion to have any chance of success.

1) Germany must early on start work developing landing craft for amphibious assaults.
2) The BEF fail to be evacuated at Dunkirk, and are instead forced to surrender to the Germans.
3) The Luftwaffe keep their focus on attacking British air assets and do not switch to city bombing.

Actually, we had this conversation today and came to the conclusion that what might make a successful Sealion would be the BEF not being evacuated from Dunkirk, but staying on and fighting (as Churchill ordered in OTL) and doing so victoriously, in that the BEF held on to Dunkirk and Calais (for example).

The Battle of Britain then gets fought not in Britain where the home team has the advantage of not having to turn around after five minutes to get fuel, but in France where, if anything, the Germans have the advantage.

As Germany fights the beachhead in Northern France, without conspicuous success, it arranges the invasion elsewhere while Britain is concentrating on Our Brave Boys in France.

Douglas · Apr 14, 2007

An insightful thought from several months ago was how useful hovercraft would have been for a Sealion-type operation. I know that hovercraft are quite complicated, but Germany developed rockets, huge cannons, and jet aircraft...what if Germany had "spent" some of that ingenuity on hovercraft instead?

Of course, as Grey Wolf said, it all comes down to getting Germany to actually think about amphibious warfare before 1940 rolls around. What if Hitler thought that Scandinavia was rightfully part of Greater Germany? Would that do it? But even that seems like a bit much of a stretch...

Tom_B · Apr 14, 2007

Hmm at a minimum you would need:

1] Some sort of prewar German interest in amphibious warfare. Maybe a single Matrosen division with some decent landing craft. One division probably wouldn't alarm GB too much

2] A prewar German program for a form of armored coastal gunboat. Slow and short ranged but it gives destroyers a very hard time. Build 20 and in exchange delay laying down Tirpitz and never start Graf Zeppelin. But accelerate Bismarck's completion.

3] Have the Luftwaffe master both torpedo and skip bombing

4] Drop tanks and a better 20mm cannon for the Me-109

5] Accelerate development of German acoustic mines a few months

6] Eliminate most or all of the BEF at Dunkirk

7] German intelligence learns of the Supermarine airframe factory near Southampton

8] Have Hitler decide on an invasion quickly. There are problems with the July invasions a la Macksey but I could see an August landing if the decision is made immediately.

9] I concur with DMA about making Ramsgate the first port to seize.

10] Pz III with long barrel 5 cm

esl · Apr 15, 2007

What seems to missed allot in these discussions is realistic understanding of Hitler’s aims and aspirations. He genially didn't expect war breaking out when invading Poland. No doubt his delusions were getting the better of him.

But its been pointed out the Munich incident changed Hitler’s mind about which threat was most important. Up until 1938 his entire aim was to wipe out the Jews and Slavs and build an empire to rival the British by attacking and occupying eastern Europe. Hitler’s hope was to trade a ‘non aggression’ arrangement with the British Empire for giving Hitler a 'free hand' European. After Munich Hitler had an increasing fear that Roosevelt was puppet of Jews that represented the primary threat to Germany, so he was torn between east and west and he could not afford to wait any longer to go to war.

Up until 1938 Hitler wanted to avoid war with the UK at all costs, until Germany was ready for war. The Luftwaffe did study on what would be required to defeat RAF back in 1937 and it concluded it was not possible without strategic bomber. But the study was suppressed and Hitler refused to act and forbid any further preparations for war with the UK. This also included the KM. As far back as 1934 Hitler was lecturing Raeder that there was not going to be any war with RN for at least a decade so no need for a hugh German fleet.

The point behind this is that Raeders building programme of the 1930s reflected this with wide spread investment in support warships as the basis of blue water navy later. However had their been a wide spread understanding that, 'being ready for war by 1940', also meant war with the RN , these building priorities would have been reversed. Allot of the support ship role built could have been filled almost as well on the cheap by civilian vessels converted to auxiliary roles or refurbished older warships, that would not cut into new warship building capacity.

This would have doubled the KM warships built from 1934-1940, but since the void between them and RN was so vast; strategic corners would also have to be cut. A Wehrmacht wide strategy would have to be fashioned to defeat the RN/RAF/RA. The indirect approach to commerce warfare could yield results but that was only a stepping-stone to threatening direct invasion to eliminate the threat from the UK. However the method of warfare adopted by the Wehrmacht was more about direct assault on the enemy after he has been weakened by fast operational maneuver and direct assault through mass.

Initial Heer /Luftwaffe plans for war focused on how to defeat Poland and France and from this tactics and doctrine were developed and adapted to meet most other campaigns in war time. Similarly a combined arms strategy for defeating UK could become the center piece for KM development and usage during the war. But being part of a Wehrmacht strategy it would have to feature direct assault of the UK.

If the go is given from the early 1930s , the ship building could be adapted as follows.

A programme to build 2 x Carriers ; 4 x Battleships & 5 x [19,000 ton] Cruisers plus 5 [22,000 ton] Heavy tankers could be replaced with 2 x Carriers ; 4 x Battleships and 10 x heavy cruisers . Without interruptions these could be completed by 1940, including one carrier in 1940 and another by 1941.

The programme to build 33 Heavy DD/Fleet tenders [3000-5000 tons] and 18 x TB/training ships [1000-2000tons] plus ~40 x new mine sweepers [~ 900tons] ; could instead be redirected and replaced by a expanded fleet programme of ~90 x 1500-2000 ton 'Großes Torpedoboot' & 1300 ton 'Flottentorpedoboot' ; built in batches through out the 1930s.

The roles of naval training could be covered by completely updating the fleet of two dozen left over Reichmarine WW-I Torpedoboot and Pre dreadnoughts. Historically only some of these were retained and partially converted in the 1930s to fill variety of roles ['tender '; 'high speed tugs', ‘high speed torpedo recovery' & 'training ships' etc].

The role of minesweeper could be instead covered by refurbishing the ~50 x “Mineboot 1916” left over from the Reichmarine fleet of the 1920s & 1930s, reinforced by up to 100 Auxiliary “Sperrbrecher”, converted from the start of the war.

The roles of 'Fleet tankers' ; 'fleet Tenders' & 'coastal patrol' craft could instead be adapted from second hand civilian Freighters ; tankers and fishing vessels purchased and converted with the funding , labor and resource devoted to the Schnellboote programme.

This could result in 10 x Auxiliary Fleet tankers ; 20-30 x Auxiliary Fleet tenders and ~100 x Vorpostenboote purchased and converted in through the 1930s. When the war began , another 250 x Vorpostenboote could have been added to this fleet by mid 1940.

Historically the German Army Engineers had been studying & practicing amphibious invasion techniques since the mid 1920s and evolved to the level of their own towed landing craft designed & prototyped in the late 1930s. Historically by wartime ideas had gone further to the point of developing & building 25 ton pontoons to be deployed from transport davits and shuttle troops armament including tanks plus supplies to the open beach. These were up powered and would still need ship powered life boats to tow them to shore.

By 1930 they had concluded that civilian merchant ships could be pressed into service with minimum modification as troop ships provided some ship to open beach transport was provided. The link between transport and open beach was to be filled by the thousands of river barges that were thought to be useful if the transport load was limited to about 40 tons . But given years of planning ahead of time, its possible the 25 ton pontoons could be better adapted to this role, since they could be transported and deployed from the transport ships themselves.

Historically exercises with this combination allowed a small freighter to unload its 800-1000 tons troops vehicles and supplies through barges onto the open shore in ~14 hours. In one exercise this included 860 troops ; 360 horses and bicycles ; 144 vehicles & 8 Pak/infantry guns plus 200 tons supplies. That’s roughly a infantry battalion plus weeks of supplies [although it was realized that enemy action and rough weather could increase this to 2 days].

Most of these transport ships had top speeds of 12-14knts , while about 12 passenger liners [11,000 troops] could sustain 15-17knts and another 8 [9,000 troops] could cruise at ~21knts. This could allow them to steam with battle fleet in the open ocean. The towed barge fleet could only average 2.5 knts but planning allowed fast currents to be exploited to average 4knts. Its probably the transports that towed barges could average 3-4 knts anyway.

By employing pontoons through the transports fleet ; cruise speed of 10-12 knts could be averaged and allowing more direct routes to be employed in addition to vastly simplify escort mission. This could reduce the cross channel trip from an massive armada of 1400-2100 vessels escorted by ~200 naval vessels for ~15 hours; right down to a fleet of ~100 ships escorted by 300 naval vessels for ~4 hours.

The designs for River barges converted into landing barge followed in the late 1930s, which explains why it only took a couple of months to assemble and complete the '2175 landing barge' step in the Sealion plan. By late 1939 this thought had evolved to massing up to 2000 of these landing barges to transport troops along the European coast line to land behind enemy lines as part of a diversion to aid a ground campaign. This barge fleet would have been towed and no consideration was given to how to neutralize RN/French fleet...that was the KM’s problem.

By early 1940 a preliminary study on small scale crossing of the channel, was done and filled away for later consideration.... again no considerations were given to how to get from A to B in the face of enemy actions.

During 1940/41 The Sealion effort achieved the following goals...
#Landing craft with 'internal ramps' and bow doors strengthened to carry AFVs and Vehicles [designed 1939 & ~2200 converted and assembled in 2 months].
#'Powered External Vehicle and AFV ramps' ,to rapidly unload AFV/Vehicles to beach [early 1941].
#'Power design units' ,to motorize landing barges [~200 per month after couple months design, Sept 1940].
#'Gun decks’, to mount army infantry guns flak and Pak on top barges, coasters and transports to provide limited shore bombardment and self defense.[Fall 1940]
#'Portable jetty' to allow rapid turnaround of landing barges independent of tide [one per division by early 1941, 1 week to install]
#'Portable harbor' to allow rapid turnaround of transport ships independent of tide [ 2-4 ordered at the end of 1941 ; one day to erect & combined with sunken coasters to create 'breakwaters']. One that was finished was used as a jetty until the late 1970s.

The KM for their part had concluded that RAF/RN coastal surveillance was so poor that with an operational maneuver involving deception, a smaller fleet could seize temporary control of the North sea long enough [several days] to launch a fleet of transport ships to land lightly armed troops along the east coast of the UK. By late 1939 Raeder voiced the opinion that employing such a force could be done when Britain was weakened from defeats on the continent and showed signs of collapse. The Admiralty fear the very same thing and voiced this to Churchill as late as September 1940.

For the Luftwaffe the problem was simple ; train all Stuka pilots in hitting moving warships. Purchase and adapt Italian air launched torpedos to neutralize capital warships and redirect the aircraft building programme to include some long range strategic bombers that could have been employed to air drop regular or magnetic mines and seal of RN ports when needed.

Its clear that Hitler’s opposition to general war with UK was the biggest obstacle to any realistic invasion plans. Had he tolerated this , most of the above mentioned steps could have been followed and knitted into a combined arms strategy to get to an invasion of the UK on the heels of an invasion of France.

From the above steps an idea of what was possible can be fashioned into a strategy. With a re focused effort ; the design labor and resources devoted to the 'Minenräumboot ', could instead be redirected to convert > 1,000 of River barges into 'powered landing barges' with 'internal' and 'external ramps' and 'gun decks'.

If planned invasion originated prewar the portable Jetties and Harbor could be completed and built by the summer and winter of 1940.The effort that went into constructing the several hundred ‘Sieble ferries‘ could instead be redirected into mass production of ~500 x 25 ton pontoons perhaps even with power units installed. That’s roughly 125,000 tons landed every 3-5 days .

If a plan is in place to utilize merchant ships as transports, the several hundred that were stranded overseas when the war began , could instead have been recalled home prior to hostilities to ensure enough to transport 13 x Infantry divisions by ship alone. The enlarged fleet could be conserved and not wasted on Norway to allow maximum leverage when the invasion occurred.

A good part of the capital ship component of this force could sortie singly or in pairs staggered weeks ahead of the planned invasion to attack convoy routes. This combined with Uboat surge would force the RN Home fleet & Anti invasion fleet to be stripped bare. With replenishment at sea these German ships could operate for months. This would still leave enough capital ships to intercept any RN Battle flotilla when it returns during the invasion.

A week or two prior to the invasion , the high speed component of the transport fleet could land up to ½ dozen reinforced infantry Regiments each with weeks of supplies.

These could storm across the North Sea and the Channel to unload units near enough to naval ports to force displacement and result in port occupation. This could be timed while the barge fleet is being assembled, to force the RN /RAF to split its defensive efforts and attention immediately prior to invasion ; at the worse moment.

Grey Wolf · Apr 16, 2007

Tom_B said:
3] Have the Luftwaffe master both torpedo and skip bombing

With regard to this, would having the Kriegsmarine have operation control of the coastal aircraft have allowed them to develop these skills ? What I am beginning to see from my reading is that Goering's obsession to keep the Luftwaffe monolithic meant that other services were not able to develop the skills they needed if they did not accord with his vision for the airforce as a whole ?

Sorry, almost out of time for this morning

Grey Wolf

Syphon · Apr 16, 2007

I have a thought about the Kriegmarine.

What if the nazis stuck more closely to the ToV and instead of the Pocket battleships, battleships and bc's they instead built more Hipper class heavy cruisers.

I believe that it might be in the spirit of the ToV if not the letter but the RN and French navies would feel less threatened by a cruiser led kriegmarine.

You could even make it real politic by the nasis and may be even up gun the hipper design to say 11" super cruisers after all the ToV stated that this was the maximum size gun that could be carried.

Either way construction would have to start way earlier maybe as soon as the Nazis gain power.

A pod my be having a HSF officer disillusioned by the way German has gone joining the Nazis and befriending Hitler and this officer lays the ground work for the future Kreigmarine in line with what might be considered an acceptable interpretation of the ToV.

For sealion to have any chance a much earlier start to the nazi ship building program is required.

Grey Wolf · Apr 16, 2007

I was wondering if there is any possibility of the Germans acquiring more ships in a serviceable condition from France, and what would have made them make the required additional effort to achieve this ?

IIRC half-complete ships sailed out of Lorient at the last minute to avoid being captured by the Germans, so if they had been quicker ? Maybe a use of targeted paratroop drops, naval assault etc ? But how would they KNOW in advance they might have a use for such vessels, and how would they have found sufficient crews for them ?

Best Regards
Grey Wolf

Tom_B · Apr 16, 2007

Grey Wolf said:
With regard to this, would having the Kriegsmarine have operation control of the coastal aircraft have allowed them to develop these skills ? What I am beginning to see from my reading is that Goering's obsession to keep the Luftwaffe monolithic meant that other services were not able to develop the skills they needed if they did not accord with his vision for the airforce as a whole ?

Sorry, almost out of time for this morning

Grey Wolf

Yes this is a good point. I had often thought a good PoD for some plausible Nazis do better TL would be WI Georing died of a drug overdose in March 1940.
Bluenote did this but with Georing dying sooner (there are are some political problems if he dies too soon) and he had a tendency to get a little air happy at times (eg. overstimating the vulnerability of ships to air power) though it is still one of the better WWII TL's around here.

Grey Wolf · Apr 16, 2007

Tom_B said:
Yes this is a good point. I had often thought a good PoD for some plausible Nazis do better TL would be WI Georing died of a drug overdose in March 1940.
Bluenote did this but with Georing dying sooner (there are are some political problems if he dies too soon) and he had a tendency to get a little air happy at times (eg. overstimating the vulnerability of ships to air power) though it is still one of the better WWII TL's around here.

True, I didn't want to wipe out Goering TOO soon for the reasons you state plus because what he did allow to be achieved was potentially vital for Blitzkrieg so needs to occur in the story before this point.

I suppose somewhere is an archive of Goering's movements and where he spent the night. One can crash a plane, or have a bomb drop on him (which I had considered in another thread), the latter being somewhat ironic and even poetic justice if it happens within the borders of the Reich after his boast about no British aircraft getting through to bomb it.

What might work interestingly is if Hitler installed Ernst Udet as Goering's replacement, passing over better qualified men. Udet could perhaps be prevailed upon to deputise and allow other services to take away some of the Luftwaffe control which would be useful in the short term.

Later we can see how Udet's other decisions contribute to problems in conquering the rest of Britain, and this can lead to his suicide and Milch taking over which would be rather more useful long term for the storyline

Best Regards
Grey Wolf

Abdul Hadi Pasha · Apr 16, 2007

I'm having a really tough time with this. The problem is that anything the Germans do, the British are going to react to. Any shipbuilding will get a vigorous response, and that's not a contest the Germans can win.

Air capability is easier to surprise someone with, but the British would have had some time to evaluate this threat and respond, and as you mentioned, too many people overestimate the vulnerability of warships to airpower. Especially over the channel, where shipping can be vigorously defended by the RAF.

Also, for an amphibious invasion, you really need sea supremacy, not just an ephemeral superiority.

I would think seizure of Gibraltar and Suez are more practicable and would be the best way to force the British out of the war. With the Med as an Axis lake you open up a lot of new opportunities.

Tom_B said:
Hmm at a minimum you would need:

1] Some sort of prewar German interest in amphibious warfare. Maybe a single Matrosen division with some decent landing craft. One division probably wouldn't alarm GB too much

2] A prewar German program for a form of armored coastal gunboat. Slow and short ranged but it gives destroyers a very hard time. Build 20 and in exchange delay laying down Tirpitz and never start Graf Zeppelin. But accelerate Bismarck's completion.

3] Have the Luftwaffe master both torpedo and skip bombing

4] Drop tanks and a better 20mm cannon for the Me-109

5] Accelerate development of German acoustic mines a few months

6] Eliminate most or all of the BEF at Dunkirk

7] German intelligence learns of the Supermarine airframe factory near Southampton

8] Have Hitler decide on an invasion quickly. There are problems with the July invasions a la Macksey but I could see an August landing if the decision is made immediately.

9] I concur with DMA about making Ramsgate the first port to seize.

10] Pz III with long barrel 5 cm