How Sealion could have been made workable?

I would like to discuss any ideas as to how Sealion could have been made workable, assuming that preparations start in the beginning of July 1940 and the BEF is NOT taken at Dunkirk. (i.e. the situation is as it was historically, but the Sealion plan is different)

 

Only possible successful plan I can see, & I stress 'possible', is to have done extensive preplanning & built HE 112's & Many MFP's.

http://www.german-navy.de/kriegsmarine/ships/landingcrafts/mfp/index.html

Trial runs somewhere in the Baltic might well have been a good idea as well.

Pinpoint airdrops with commandoes to hit radar installations, ( or commandoes landed by U-boats ), would be a good adjunct to the overall strategy. They might hit a few airfields as well, toss some grenades & fire machine guns at parked planes, they'd be mostly rounded up, but could do serious damage, & released after invasion complete, if successful that is.

Overwhelming size of British navy biggest problem.

 

the Germans had no landing craft to speak of so first planning them and then the trials etc would take a couple of years at least.Also they´d have to destroy the RAF and the RN first to have any kind of chance and still there´s the army and bunkers waiting.

If you compare to Overlord there was total air dominance in 1944 for the Allied, the navy was there with big ships, the Germans were surprised, they had landing craft and yet something like Omaha happened...

And the Germans would not have the Mulberry system so getting the supplies in would be rather complicated.

 

Go straight into England after Dunkerque, but as the Wermacht were not expecting such succes they failed to plan for it. The shipping could not be conjured out of thin air!

 

Regarding the supply system I though- what if the Germans used all their bombers and transports only for supplying the troops and the fighters to protect the supply line?

 

I would say the Germans would have had to invade right after the fall of France and perform a mission similar to that of the invasion of Norway with transports landing troops in ports taken by paratroops. Great Britain's greatest weakness would have been the lack of an army. It's strongest asset would be its Navy. The chance of success....

 

If the Germans were to manage to do it all, they would have had to go on the heels of the British withdrawal from Dunkirk. A possible, but definitely costly, method would have been to pull a 'Japanese' amphibious assault. The French campaign still had to be won so that fighting would continue into late June.
While this is going on the Germans immediately begin to round up everything that floats (little motorboats, row boats, sailboats, fishing vessels, everything) and move it to various Channel ports. At the same time, they pull and prepare say 4 to 6 infantry divisions for the invasion. The available parachute units are also quickly refurbished and readied for a drop.
Then with the surrender of France (or immient surrender) the Germans drop their paratroops in Britain with the intent of taking one or more ports. Simultaneously they push their "fleet" of everything that floats across the Channel with the intent to land say four or five divisions of infantry to secure the ports the paratroops have taken. The initial wave will be short heavy weapons and artillery but they are ashore and face very little credible British response. Outside the 1st Canadian Infantry Division there really is nothing in England to defend it with in early July.
At this point with troops ashore the Germans need only expand their bridgehead to the point where air transports can land supplies reinforcements. At the same time the Luftwaffe is now primarily used to secure the sealanes against the Royal Navy. If the Germans can send transport ships across the Channel by day and then unload them they have the potential to not only maintain but even expand their foothold. Just a few transports loaded with the troops and equipment to land even a handful of fully equipped units within a week or so of the inital assault could have made this possible given the lack of British capability in late June early July. By September it is too late.
It is a very thin margin that this would succeed but it is likely the only chance the Germans had to make an invasion of England happen.

 

Would the Brits had had time to sabotage any ports? What about the RAF who flew at night? Seems they could've played a role in bombing any night time surface vessels.

 

Whether the British are able to do much to sabotage ports would depend largely on how much time they have to respond to the German preparations to invade. Given the state of the British army in June - July it is likely that not much more than basic demolitions could be accomplished.
Whether the RAF flies by day or night if the Luftwaffe is primarily engaged in anti-shipping operations and supporting their air lift with a secondary mission of ground support it should be well within their capacity to at least maintain parity and make British naval operations by day difficult. The RAF cannot bomb naval vessels at sea during nightime with the extant technology of 1940 so this would be virtually out of the question except in exceptional circumstances.
If the Germans can maintain some degree of air control over the Channel they can move their shipping to ports they control by day under heavy escort largely negating the British naval superiority locally in the process. With a port or three under German control this makes the whole operation possible. Without these, landing over the beaches is a doomed venture.

 

Negating British naval superiority is not such an easy trick. & the British could well guess which ports the Germans would be after. & mine the entrances & would likely station heavy units around these ports.

MFP's can land nearly anywhere,( flat beaches anyways ), But let's assume they do get enough men & tanks ashore, gas is their next biggest prob to solve, which MFp's would go a long ways towards solving, & the 1st objective would be the southernmost British airfields, for 2 reasons, deny them to the enemy, & more importantly to get additional fuel & supplies in. & as well have a forward base for the fighters.

Once tanks ashore with sufficient gas & a couple airfields taken, it would be game over. It surprises me that the Germans didn't consider the possibility of a cross channel op in the 30's & do some sort of preplan work & were short sighted as regards landing craft. An MFP does not require tons of materials, nor does motorized landing barges which were later used in med, ( both of which are shallow draft & much harder to hit with a torpedo than other craft ). Hitlers preoccupation with land matters & not wanting to go to war with England the likely culprit.

Essentially it all hinges on gas & tanks getting across.

 

The original question asked if the Germans had no previous preparation time other than that they had historically (eg from the fall of Dunkirk or about mid-June 1940). This precludes using purpose built MFPs or Siebel Ferries both of which were non-existant and would take many months, if not years, to procure in sufficent numbers.
As for construction, an MFP does require "tons of materials" about 300 in the finished product.

 

True. Now on the subject of possible landing sites, one obscure thought,( which would need serious study ), is the cliffs of Dover. I'd try 3 separate landings for 2 reasons, enemy can't contain all of em, & hopefully one of em will achieve the all valueable element of surprise.

They wouldn't expect a Dover landing simply because getting the tanks up & over presents an engineering challenge. It is the shortest distance which gives it a nice advantage over other areas.

If one could find 2-3 low points in the cliffs & send construction groups in to built ramps sideways from the beach to the clifftops, ( very quickly! ), one might have something. many engineering questions arise naturally, i.e. is the sand hard enough? How long would it take to build 2-3 of these, would the required material fit easily in small craft, & how easy would it be for a British plane to drop some bombs & blow it to pieces.

The construction crews would have to drill it til they could do it in their sleep.

& the Germans did aquire small craft with tank carrying capacity with makeshift exit ramps. Some even had large propellers added on like Florida swamp craft have to add speed. Saw an interview with a German who was involved in building these in French ports facing the channel on a BoB documentary & mentioned these.


http://www.z3roadster.net/articles/route_southern_england_03.asp

Terrain looks ok for tanks.

 

Have a scroll through these. Looks like a couple good spots where tanks could navigate.

http://www.harganonline.com/regions/gb/england/whitecliffs.htm

 

I have a few ideas...

If the BEF gets back to england with almost 34 divisions [338,000 troops], I can see why the Germans have too win quickly if at all. Assume that it takes england the rest of June thru July and august to begin reorganizing and re-equipping and redeploying these divisions. I am assuming that these divisions had lost all transport, supplies, equipment etc and had retained [at most] the soldiers personnel weapons only. Given that these troop would be largely scattered along the channel cost, with no effective communications, I would go with T.A.Gardner's plan with these changes.

If you have a window of just 2 3/4 months before the Brits will start getting the Dunkirk troops operational in sufficient numbers to make an invasion impractical, then you must act as quickly as possible. The French campaign would get the undivided attention of the German armored divisions, and all but a few of the Infantry divisions.

I would turn virtually the entire Luftwaffe loose on england immediately [June 5th]. Britain would get hit with the airborne troops as soon as possible. The airborne troops would not attempt to take and hold a port [which you would not be ready to use for a month or so, but would instead assault and capture as many of the lower England airfields as possible, and immediately begin airlifting troops and supplies following their capture.

By not just attacking all the lower england airbases but capturing as many as you can asap, you will force the withdrawal of the RAF into middle and upper england and will hopefully have accounted for a sizable portion. You thus negate their radar warning, prevent spoiling attack upon your harbors and invasion shipping, and gain the ability to base as many aircraft from these southern england airbases as you can.

If an airborne division contains say 10,000 troops, then drop a company sized element at each of 100 airbases. Send in several successive waves of fighters too draw the Brit fighters into the air and lead them as far from their airbases as you can. Brief your first too waves pilot's that their goal is to make the defending fighters use up as much fuel as possible. If the waves come in 15-20 minutes apart [with the first wave breaking contact once the second wave arrived}, then the Brit fights will have been aloft for an hour or so by the time the airborne troops transports are arriving over their airbases. By the time the defending fighters break off and return [hopefully to low on fuel to make it to another airfield that isn't already in German hands], all the aircraft on the ground will have been captured/destroyed.

Once you have built up enough troops by airlift, then expand your perimeters and take the ports from behind. The Dunkirk troops, trapped south of your forces, would never be able to be resupplied and thus would have escaped only to be captured in southern england.

[ 04. January 2007, 12:57 PM: Message edited by: Shadow Master ]

 

Would beaching ships help?
Germans had some 168 merchant freighters designated for the invasion with 700 000 tons of capacity. What if they beached portion of them during high tide on the english coast at predesignated points? That can be a lot of equipment /supplies.

 

The variant with attacking even before France fell seems to me problematic, considering that Germans didn't want to jeopardise their conquest in France.
And they still needed to move their shipping to the French coast and to rebase the airfleet...
At the very least 2 months of preparation seem unavoidable to me..

 

It would definitely be a risk [prize understatement]. My feeling is that time would be working for the Brits and against the Germans. My proposed airborn/airlift would be done WHILE you were massing your shipping.

Historically, Paris falls just 10 days after Dunkirk, and the formal surrender takes place 8 days after that. If you want to shake things loose, you would have to take risks the Germans historically didn't. Were the German armored and infantry divisions helpless to Finnish off the French without massive air support? If you wait two months too invade, you'll have given the Brits time to organize those 338,000 troops to oppose your invasion.

What specifically are you proposing the Germans do DIFFERENTLY from the historical case?

 

The first thing would be to go from France to England without stopping. France can be subdued after a foot hold was gained on England. All out slaughter of the BEF would be in order before and during Dunkirk. The Germans would need one or two ports with nearby air fields. commando teams going ashore while paratroops land around the airfields. Once the airfield were secured, fighters would secure a corridor while support equipment and troops were landed. Once the ports were secured, more supplies and troops can be brought in.

All this depends on numerous things and how the British react. An all out resistance by the British fleet could have several effects. Or if they decide to sail to safe areas, attack targets of opportunity, etc.

 

As long as they had ramparts of some sort, in other words, a way to unload. that is a fair point Leopold. Punch a hole in the hull & build a ramp perhaps. It's a one way journey & ships might be towed off & repaired later.

 

The gross points for success are:

1. The Germans must cross before the British recover from their defeat in France and more specifically, Dunkirk. Once they recover sufficently to field a fair number of reasonably well equipped divisions the Germans stand no chance of making an invasion.

2. Trying to defeat the RAF outright is a losing proposition for the Luftwaffe. The Germans once ashore can manage without air superiority to fight effectively.

3. Any landing because of 1 above must take place as quickly as possible following the British defeat at Dunkirk. The French are already finished and applying 4 to 6 divisions to an invasion of England will do nothing to German operations in France.

4. The primary role of the Luftwaffe in such an operation is sea denial not air superiority. The Luftwaffe's priority must be to open the Channel to German shipping during the day. This allows merchant ships to cross and reinforce the landings.

5. Post a successful initial landing the most important thing is to first aquire a port large enough to allow reinforcement and supply of the forces ashore. There is no way the Germans can supply a useful force ashore over the beach. A port is the only way the Germans can possibly supply their troops long term. It does not matter if the port is fully functional so long as some piers or quays are usable.

6. The only way 1 and 3 can be met is for the Germans to aquire any means currently available to cross the channel. Use of smaller but very numerous craft increase the chances that most will successfully make it to England versus trying to ship units over initially in large merchants which are both easier to detect and far more concentrated in terms of losses. Tow them, row them, sail them, or motor over but do it quickly and with sufficent numbers to get and stay ashore; nothing more.
The other advantage for the use of small craft is that they can easily be beached, their loss is irrelevant once at the invasion point (ie there is no intention to reuse them) and sufficent numbers should be readily available to send 20,000 or so troops over nearly immediately.

If the Germans can manage to get and stay ashore then things get a little easier for them. First, if they have a port then they could organize small convoys of say 2 to 4 freighters that proceed across the channel in daylight under heavy escort by both destroyers and aircraft. The crossing shouldn't take more than a few hours. These would then unload and return in a few days under escort that doubles by bringing over another convoy.
The German initial strategy should be to expand their bridgehead sufficently to allow an eventual build up for a general offensive to take the island or force the British to negotate a peace.