Fascinating discussion â€" great topic Sebigboss79!

I tend to agree that the deciding issue would have been one of supply. Even if both ends of the Dover Straits were successfully mined (and I’d contest that that would be a big “if”!) then it wouldn’t take long before this line was breached by the Royal Navy.

If the MBTs and Destroyers based at Portsmouth were to get amongst the supply vessels I don’t imagine they’d last long.  Assuming then that some airfields were captured intact (although many were mined to prevent their use by the enemy) I cannot see the Luftwaffe being able to cope with the quantity of supplies required, particularly as their losses increased over the course of the campaign (look at the losses suffered later by the Luftwaffe during the invasion of Crete).

In short, even after an initially successful invasion I can see the Wehrmacht running out of petrol before too long â€" just look at Operation Dragoon; despite the huge resources available to the Allies, the lead units, who had landed in Southern France on the 15th August were suffering from severe fuel shortages by 20th August - IIRC this was also with uncontested supply routes!

We are all quite happy Sealion did not work out I am sure but I would like to open a discussion about eventualities.

1. Two days before Sealion massive airborne assault in Southern England. Faint assault in the Midlands by sea and air.

'Msssive' airbourne assault using what?  The Germans had very few air landing units at the time.

An assault in the Midlands?  From where?  Using what?  The Germans had no sea trasnport fleet to speak of, and the RN together with the coastal batteries and RAF would have neutralised the Kriegsmarine.

2. Possibility of German "commando" raids to capture Churchill and/or the King.

No possibility at all.

There may have been the slight possibility that suicidal assassins could have killed either Churchill or the King but even this is remote at best.  Far more likely that either chap would have been killed in the Blitz.

And what would killing or capturing either of these men have achieved?

3. Immediate positioning of airpower in captured airfields.

Except the airfields were well defended (with numerous inward-looking pill boxes, hard points and trench defences), heavily mined (preventing 'immediate use'), and there were Home Guard units dedicated to sabotaging the airfields if captured.

4. Beaches under attack from landside (Singapore reloaded) and successful arrival of equipment.

'Landside'?  Who's attacking and from where?

If you're talking air-landing troops, isn't this a breach of basic air-landing doctrine of the time?  (That airdropped troops are their to interdict enemy reinforcements, secure routes inland, etc.?)

The attack on Singapore was somewhat different wasn't it?

5. Response time of the Royal Navy? (I give it 2 days minimum to arrive. Assuming no interference by Luftwaffe, submarines or mines)

OK, lets say the RN is delayed in engagements with U-Boats or possibly German surface fleet action (the improbability of Luftwaffe action has already been well covered).  Lets say, in fact, it takes 4 days for the RN to arrive, as they also meet and have to clear a path through a mine-screen.

Once the RN is in the Channel, the games up for Jerry...

Sealion is a great 'what if' scenario, but given the realist assessment of the situation at the time, Hitler made the right choice not to invade.

Personally given the boats available to the Germans i think its simply not possible that an invasion would or could happen.  They may have got lucky with the weather and managed to put a first wave onto England's south coast beach but that would have been pretty much it.  Any advance beyond the South Downs Ridge, without serious, full-scale resupply and reinforcement was never possible.  Germany simply did not have the neccessary materiel nor the strategic and tactical advantages to pull it off.

I think there's also a more compelling arguement - Hitler never intended to invade in any case.  The posturing was intended to force a treaty with Britain, secure his western front and open the primary engagements to the East.  As i understand it, crudely Hitler's offer to Britain was 'i'll have Europe as a German land-Empire, you can have your sea-Empire, lets call it evens'...

I beleive Hitler nevver really intended to Invade Britain it was a major bluff to get us to sign a treaty so he could look east and get his living room frmo Russia. But I feel some of the facts here are distorted.

the Luftwaffe in 1940 after the B.E.F had escaped back to britain had started a quiet substantial campaign against British shipping travelling down the East coast. This was partly to force the R.A.F to engage it's fighters over the North Sea. thus partially negating the return to fight/POW effect of fighting over the South east. for this campaign they used JU87,JU88 and Me110's to attack the shipping with the ME109's flying fighter cover 

for the

For the British Home Fleet to get to the Chanell it would have to travel down 2 very constricted waterways to get there in a very short time the Eastern group would have to travel down from Scapa Flow down the East coast of the UK they would of had a lot of German surface ships, Minefields and attacks from the Luftwaffe. The Western group for speed would have to travel down the Irish sea. 
Again you would not have to destroy these capital ships to be effective you only need one effective mine or Torpedo to slow down one of the Capital ships would the other ships leave this or race on to defend the Islands. 
Also the main plan of the British Army at the time was to defend the beaches then Fall back to the GHQ line, and we all know how well these lines are good at being defended. I think the main question here is would the British Land forces be able to hold out against what was at the time a very Battle Hardened German Army.
just my ten penny's worth 
regards
Sean

From what I have read, main reason the British government was so concerned about an invasion was because they were not willing to risk their capital ships in the constrained waters of the channel. Capital ships were viewed not just as weapons of war but 'power', a threat, and necessary for bargaining should the worst happen.

Royal Navy command knew that sending Capital ships into the English Channel would be suicide if Germany had air superiority (which they did) due to the threat of u-boats. The effective weapon against u-boats was destroyers of which at least 30 had been sunk already by the Luftwaffa if I recall correctly.

The two primary reasons Sealion wouldn't have succeeded, lack of an invasion fleet capable of putting a battle worthy army on the beaches, and the fact Hitler still believed England would seek terms.

Cheers,

Kev

Quote from: Squirrel on 07 January 2013, 07:17:17 PM
Royal Navy command knew that sending Capital ships into the English Channel would be suicide if Germany had air superiority (which they did)

When did the Luftwaffe have air superiority over the Channel? 

Quote from: sebigboss79 on 05 January 2013, 07:40:13 PM

1. 25 Battle hardened divisions invade an island that has not been facing invaders in a thousand years, give or take.

Battle hardened, where?  Most of the German forces that invaded Poland spent their time following an enemy that was falling back to a better defensive line, which was almost immediately made untenable by the Soviet invasion that subsequently led to the Polish defeat (but not surrender).  The speed of the advance during the invasion of France created a similar effect. The first time the German forces faced an enemy in force, fully determined to fight was when Rommel attacked Tobruck. There they faced 200 years of concentrated British belligerence in the form of the 9th Australian division. The Germans received a bloody nose.  Coincidentally this division had been formed from Australian units sent to protect Britain from German invasion in 1940.
Some units saw combat in these invasions but ’25 Battle hardened divisions’ I hardly think so. Motivated with a (possibly falsely held) high morale yes, battle hardened no.

Quote from: sultanbev on 06 January 2013, 01:58:24 AM
The Luftwaffe couldn't operate at night. The Royal Navy could. 50x DD, 20 Cruisers and a few BB converging from 2 directions = dead invasion fleet. That's excluding auxiliary craft like trawlers armed with 12pdrs and Lewis guns and MTBs. it would only take 1 fleet DD to get in amongst the landing barges to destroy a battalion. The barges were quite tough, so almost bullet-proof, but only capable of 4 knots on a flat sea, most were towed, so sink the tugs, 6x 4.7" guns and 8x 2pdr pom-poms is going to make short work of a gaggle of wooden boats that are drifting, even if some were armed with 37mm PAK36 or 105mm FH18 howitzer in fixed bow mounts.

Not to mention the MGBs and MTBs of the Coastal Forces. Exercise Tiger and Slapton Sands come to mind.

Wow, I often read quite stupid stuff from Brits when it comes to Germany and WW2, but this one puts it over the top. The Wehrmacht lost 17.469 Dead and 36.995 wounded in Poland alone..quite a few for a relaxed promenade to Warsaw. And not to forget those 46.059 (!) German soldiers who were killed in France. Its a real pity that "Die Blitzkrieg Legende" by Karl-Heinz Frieser has never been translated into English for it does away with a lot of myths sourrounding the early campaigns of WW2.
Oh yeah, but I forgot, the first real battle was of course against those British uber-forces in North Africa (" 200 years of concentrated British belligerence"   may god be with us) everyhing before that was just kindergarten.

Quote from: Luddite on 07 January 2013, 07:25:45 PM
When did the Luftwaffe have air superiority over the Channel? 

Around the time that they were bombing our cities with impunity and the RAF  were fighting for their, and our, lives. At that point there was no way the RAF could have protected Capital ships from air attack, just as they couldn't during the Dunkirk evacuation.

I often think people forget how close we were to defeat, which actually devalues the the valour of those who continued to fight.

Cheers,

Kev

Quote from: Squirrel on 07 January 2013, 08:42:22 PM
Around the time that they were bombing our cities with impunity and the RAF  were fighting for their, and our, lives. At that point there was no way the RAF could have protected Capital ships from air attack, just as they couldn't during the Dunkirk evacuation.

I often think people forget how close we were to defeat, which actually devalues the the valour of those who continued to fight.

Cheers,

Kev

Hmm...i'm not sure the Luftwaffe achieved air superiority.
We were technically at air parity...  http://en.wikipedia.org/wiki/Air_supremacy...hence the possibility of Operation Sealion speculation.   

Hi

Been a fascinating topic

Few points

Freisner's Blitzkrieg Legend IS available in English - published by Annapolis Naval press - get it on Amazon - superb book on the myths of May 1940.

Also do not forget RAF not purely defensive force and made numerous raids on the harbours and Rhine collection points for the prajms/ barges and transports - these were certainly stepped up as September approached. As German radar limited/non-existent the Luftwaffe spent much time on readiness and patrolling duties to protect these points - to protect these as well as project power over Southern England was stretching them beoynd their capability

The slow cross channel convoys - probably going slower than Caesar's invasions even in good weather - meant they were a hostage to fortune. Even if sufferred low losses to do the return journey, refuel and reload and do the next journey meant there was no rapid surge and buildup. Even with a modicum of resistance ammo would soon have run out.

As for the dream that Stalin would help Germany at the operational level is stretching the commitment he had with the Nazis - resources yes, but his hope was a long Franco-German war. When this failed to materialise the resources went up - fear and the hope that this would delay any thoughts of the east. If SeaLion went ahead it would have been intriguing time in the Kremlin - defeat of England would have meant they would be next and would perhaps have pressed them for a more belicose stance. Stalin being the reader of history would have viewed it from perspective of 1809 and Alexander change of stance as Napoleon became embroiled in Spain to demand more control in the East after having been bosom buddies only a year or so before at Tilsit or in his case the Molotov-Ribbentrop pact

Finally one rather cynical wargame mate of mine said Sealion could be gamed in 1 die roll - Each pip being 1 day before the German's surrendered. I think he had a point - it was always more of a threat than a cogent plan

Quote from: Luddite on 07 January 2013, 03:51:21 PM
We are all quite happy Sealion did not work out I am sure but I would like to open a discussion about eventualities.

1. Two days before Sealion massive airborne assault in Southern England. Faint assault in the Midlands by sea and air.

'Msssive' airbourne assault using what?  The Germans had very few air landing units at the time.

An assault in the Midlands?  From where?  Using what?  The Germans had no sea trasnport fleet to speak of, and the RN together with the coastal batteries and RAF would have neutralised the Kriegsmarine.

2. Possibility of German "commando" raids to capture Churchill and/or the King.

No possibility at all.

There may have been the slight possibility that suicidal assassins could have killed either Churchill or the King but even this is remote at best.  Far more likely that either chap would have been killed in the Blitz.

And what would killing or capturing either of these men have achieved?

3. Immediate positioning of airpower in captured airfields.

Except the airfields were well defended (with numerous inward-looking pill boxes, hard points and trench defences), heavily mined (preventing 'immediate use'), and there were Home Guard units dedicated to sabotaging the airfields if captured.

4. Beaches under attack from landside (Singapore reloaded) and successful arrival of equipment.

'Landside'?  Who's attacking and from where?

If you're talking air-landing troops, isn't this a breach of basic air-landing doctrine of the time?  (That airdropped troops are their to interdict enemy reinforcements, secure routes inland, etc.?)

The attack on Singapore was somewhat different wasn't it?

5. Response time of the Royal Navy? (I give it 2 days minimum to arrive. Assuming no interference by Luftwaffe, submarines or mines)

OK, lets say the RN is delayed in engagements with U-Boats or possibly German surface fleet action (the improbability of Luftwaffe action has already been well covered).  Lets say, in fact, it takes 4 days for the RN to arrive, as they also meet and have to clear a path through a mine-screen.

Once the RN is in the Channel, the games up for Jerry...

Sealion is a great 'what if' scenario, but given the realist assessment of the situation at the time, Hitler made the right choice not to invade.

Personally given the boats available to the Germans i think its simply not possible that an invasion would or could happen.  They may have got lucky with the weather and managed to put a first wave onto England's south coast beach but that would have been pretty much it.  Any advance beyond the South Downs Ridge, without serious, full-scale resupply and reinforcement was never possible.  Germany simply did not have the neccessary materiel nor the strategic and tactical advantages to pull it off.

I think there's also a more compelling arguement - Hitler never intended to invade in any case.  The posturing was intended to force a treaty with Britain, secure his western front and open the primary engagements to the East.  As i understand it, crudely Hitler's offer to Britain was 'i'll have Europe as a German land-Empire, you can have your sea-Empire, lets call it evens'...

One after the other:

1: They DID. It would have stripped them of even a Fieseler Stork to bring the Führer his lunch but it WAS feasible.
Assaulting the midlands was planned to be from norwegian ports. As stated in my initial post the Kriegsmarine HAD solved the transportation problem. We are not talking about a sustained supply route but an assault! Planned were 6 large merchant ships. Initial plan called for a total of 400 men on those ships (command style) just to flush the RN out. The sense of such an approach is debatable. A direct assault would on the other hand lead to RN involvement - which was the only goal of this diversion in OKW's plans! My idea is why not expand this and actually give the Brits more t handle than they can. We are not in the "this is Britain, we win". Such an attitude I would contest back to the AWI where you lost cos the French and (military good) Germans fought on the other side. Wellington did not win Waterloo, it was Blucher turning his army around and march them into battle again and still it was a close one!

2: What would it achieve? Well shock. The CIC, King, Military commanders are dead. Even if you have replacements immediately all Britain would know that NO ONE is safe. Thats all the sense there has to be for such an attack.

3: Surprise air assault by a massive force does not lead to automatic victory but your argument is more patriotic than military sensible and viable. British airpower is decimated in such a scenario. Defense of abandoned airfields is highly dubious at best. I do not think anyone can keep a whole airbase (abandoned) fully manned to repel a hypothetic assault. Such an assault would have been daring and rather unconventional, ergo a determined assault is likely to succeed, bunkers or not. I contest that the Atlantic Wall was a much better defense than those and yet it was breached withing hours.

4: Airborne troops landing directly behind the beach defenses. Beach defenses were strong under Ironside and only thinned out when Brooks changed the strategy. No matter how strong they come under attack from 2 sides. Not the position you wanna be in. Supply and troops are 2 days away under Brooks. Plenty of time for a 2 sided attack to succeed.

5: Correct. ONCE they ARE in. Delayed by Submarines and air attacks. Military sense of sending a battlefleet into confined sea, dominated by enemy air, aside I still conest much of the RN would actually arrive AT the channel, only to be sitting ducks while german shipping is held in ports to conserve it. The outcome of such a move is easily predicted.

6. Germans never had FULL air superiority. PARITY as you correctly identified it, was well enough for the British.


@Squirrel: Hence the IF. Air superiority has been and still is the key. As well as the element of surprise and use of unconventional tactics.

@J.S. The "stupid" is less to the fact of missing knowledge but an ongoing "Imperial" superiority feeling. Same with Americans. Please people, this is not the place for "we have won, we are right" attitudes. It is clear to any informed person that WW2 was a no-win situation for the Germans. All they could do is hold the storm as long as possible. So PLEASE keep it free from 70 year old resentments and on topic!

Fact is Stalin was only waiting his time. He knew he was next and hoped to delay German attack untill 42 if not 44 when the Red Army had been ready.

Fact is America would, at some point, have intervened. HOW remains open to debate but they definately would not watch Hitler terrorising the world.

@Bernie: Correct. As said before Hitler had his illusions about Britain untill the end. I think the Wehrmacht woke up in '42 when ordered to attack the Kaukasus, leading tot otal defeat of a whole front. How come German and British officers are said to have been celebrating together on D-Day?

As stated befre it was such closer than people may think or admit nowadays besides knowing better.

I do not see the speed of the crossing as a problem, IF heavy equiment and tanks is their main cargo and the men arrive via air. Mind you my hypothesis is much different from both real plan and the Sandhurst wargame. Stills upplies are the key, mainly ammo as food would have been requisitioned from the population. AND lets not forget a German blockade by submarines would have a similar effect on all British so supplies are hard to argue in any direction. Given majority of the land is still in British hands it is easier for them as for the Germans.

With airsuperiority at the landing site and transports both sea and air available (for air a big IF concerning losses in the initial assault) it is as Luddite said "on even terms" and unfortunately a landbattle on even terms is a cakewalk for the Germans.

For the argument of battle hardened troops. The losses speak for themselves and you are not really saying the Allies were also just running away in France, are you? The German Army at that time simply was not stoppable. The only incident untill Africa (overpowered and outproduced rather) and Soviet Union (madness) was when de Gaulle, against his orders, requisitioned a tank batallion and actually attacked the Germans who were on the verge of breaking. Being recalled and the failure to exploit the successes of de Gaulle lost the campaign. There was rumours that de Gaulle was intended to be shot for "dereliction of duty" and "disobeying a direct order".

Soviet help is neither needed nor implemented in any of those 3 plans. But what if? I am not aware of Soviet airborne capabilities but Stalin had no problem sending millions against the Germans. Ever other man gets ammo, the man in front of him the gun. Another suicide raid maybe against Scapa Flow? Interesting thought there 

The following links give an idea of what happened during the Sandhurst wargame, which is of interest given the above points of view:

http://en.wikipedia.org/wiki/Operation_Sea_Lion_:_The_Sandhurst_Wargame

http://mr-home.staff.shef.ac.uk/hobbies/seelowe.txt

I don't have the Macksey book to hand, but IIRC he gives the pre-conditions the Germans would have required to be able to launch a seaborne operation with some guarantee of success. If I get chance I will see if I can dig them out tonight.

Good debate though .

Some very interesting documents  from a year or so after the threat of invasion. Well worth a look.

http://www.da.mod.uk/colleges/jscsc/jscsc-library/archives/operation-sealion

Quote from: Steve J on 08 January 2013, 01:43:01 PM
The following links give an idea of what happened during the Sandhurst wargame, which is of interest given the above points of view:

http://en.wikipedia.org/wiki/Operation_Sea_Lion_:_The_Sandhurst_Wargame

http://mr-home.staff.shef.ac.uk/hobbies/seelowe.txt

I don't have the Macksey book to hand, but IIRC he gives the pre-conditions the Germans would have required to be able to launch a seaborne operation with some guarantee of success. If I get chance I will see if I can dig them out tonight.

Good debate though .

The whole idea of said wargame is to be contested. One assumption was that the invasion was attempted WITHOUT proper air support and lack of air superiority. I believe we concur how viable such attempt and how much biased the end-result therefore is. Why did Sandhurst actually allow the Germans guns and tanks? Ah, ok would have been a bit too obvious then.

Tilting the balance to one side by making the enemy overly stupid is not really academic or serious! HENCE the room for us to speculate.