Could Operation Sealion really have succeeded?

No problem. I've hit that limit a few times myself (I'm sure your shocked ... not).

I thought that was pretty much a given.

I assumed that the person that wrote that had some sort of at least feel for the transport capacity of the Germans at that point in time. I guess it depends on when they start gathering the cargo vessels I agree that in July there won't be many barges nor will there be time to modify many in the time frame give. Of course if you are talking cargo ships rather than barges that shortens the warning time. It also however means the transports are sitting longer off the beaches and the "impulse" of the landing is far less. If it's only parts of a division then it also allows for concentration by the British against it. Unless of course they think it's a feint which is quite possible. Not sure a one division landing is going much of anywhere though.

 

It hardly matters what the law says with regards to selling weapons to belligerents, when there is a presidential list of exceptions. Any such list is going to be partisan, is it not? Additionally, the Commonwealth (and France's) presence on such a list is entirely an issue of politics, which in democracies, can be rather fickle (such as depending on which president, public opinion of countries on the list, etc).

It is actually, entirely irrelevant in May-June 1940, whatever FDR's personal involvement is, or what he and Churchill discuss in private, as he has yet to win the election, and therefore, with the prevailing sentiment in the US (both public and Congress) at the time, cannot do more. Therefore, there was no guarantee that the US would become more involved. If, somehow, the UK was invaded and surrendered (enormously unlikely), then the US would likely just remain antagonistic towards Nazi Europe, but wouldn't be starting a war. It'd be a similar situation to the cold war, instead.

Taking sides is one thing. Joining the war and having your boys die is a totally different level of commitment altogether. Immediately after the surrender of France, it was only the Commonwealth that was doing the dying for democracy. I'm sorry, but that's the way I see it. It doesn't matter what the president thinks, wants or intends. FDR has to get public acceptance, and get past Congress. 18 months later, that's when the US actually joined the war.

It is easy, looking when looking with hindsight, to assume everything is a foregone conclusion. Churchill, and the UK, in June '40 could not afford to make such conclusions about a more active US participation. Just as Germany had to assume the opposite.

But back on track; with regards to the RN's commitment to defending the UK with all available resources, the RN's capital ships could not just run away to Canada, leaving the UK to fend for itself, because the public would not understand in the least. The public of the Commonwealth sees the US as well-intentioned, but in no way committed to the cause. The German "stab in the back" myth would pale in comparisson. Because the crews were British. Because without Britain, the Commonwealth isn't. It doesn't matter that it might be a smart move militarily. Politcally, it would spell the end of the Commonwealth. The RN, the most proud branch of the armed forces, fleeing at the time it's most needed. PM King was rightly horrified at the mere suggestion.

 

Gunslinger...

Okay, there are some big flubs in there

First of all - "By 7 August 1940, a few days before the Battle of Britain started..." The official campaign dates for the Batle of Britain are July 10th to October 31st 1940. July 10th until 11th August was the "Kanalkampf" period of the Battle, culminating in the massive air battles across 48 hours over the "Peewit" coastal convoy. There was then a 48-hour relative lull compared to what came before...and after!...which segue'd into Adler Tag on the 13th and the start of the bombing offensive against the RAF on land.

The second is the number of squadrons - "...32 squadrons, compared with 19 squadrons of faster, but harder-to-build Spitfires"
As of the 1st of August there were 30 Hurricane squadrons in Fighter Command, with 19 Spitfire squadrons.

So what made up the other NINE in the OOB? Seven Blenheim IF squadrons, and two BP Defiant squadrons.

As for this - "the totals had grown to 2,309 Hurricanes and 32 squadrons" - the RAF may have had 2,309 Hurricanes "built" in total at that point...but 30 squadrons of Hurricanes only equals 720 aircraft at full establishment per squadron

Some "encyclopedia"-type books are great - some bear VERY rigorous crosschecking with other sources

 

So They could only use 720 for every squadron available total? The rest were spares and back-ups then I take it?

 

LWD...here's the "timing" funny for an early Sealion...

Given that Sealion wouldn't be launched without (local) air superiority - SOME form of attritional air battle would have HAD to have been fought and the RAF come off worst for Sealion to be launched at ANY time....early or late

But an attritional air battle fought IN JULY finds Eleven Group Fighter Command STILL terribly attrited after France; it had lost half its aircraft there. That's why the weeks between the Armistice and the first week of August....the events of the Kanalkampf notwithstanding...were so important to the survival of Fighter Command. It allowed those losses in aircraft and trained pilots to be made up.

Here - they wouldn't have been...

It's still going to be half-light when the first wave is out-going again...as for the second wave, the MAIN air battle is still going to be oing on OVERHEAD, Ju52s dropped their human cargos as quite low heights! They'll take SOME losses...but not many - RAF fighters are going to be VERY busy doing all those other tasks I mentioned.

As for being resupplied - the FJ dropped with supplies for some days - that was the 2xdespachers' job, getting the men out THEN getting the supplies out - in parachute containers, wicker baskets etc..And in this case the plan was to have Lympne in German hands before nightfall....or at "worst" the landing forces would be pushing up from the beches by then. Remember - you can SEE the piosition of Lypmne airfield from the beaches! At closest it's only 3 miles away IIRC.

This was the caveat that the Heer forced on the Luftwaffe; that ANY massed para drops be within EASY reach of the beaches for relief, not 20-30-40 miles behind enemy lines like in Holland!

But that's the thing The British only have to SEE the effort being put in....and they STILL have to take ALL possible precautions! Which slows their entry and exit from the Narrows...each time!

I say "each time" because as at Crete i 1941 and Norway in 1940, destroyers are going to find their AA munitions severely depleted very quickly. There is absolutely NO point them staying around when they become vulnerable - that way sees them going to the bottom of the Channel in short order....just like off Crete

So it's back out of the narrows to the nearest RN depot...there are a few up and down the coast that aren't often taken into consideration, it meant that ordnance could be stored outside major ports, and that RN vessels didn't need to cross booms, wait on river roads' being swept etc., before re-arming and returning to the fray.

I'm not sure it does; IIRC the KM had teh majority of their mines stockpiled at the assigned Channel ports quite quickly, to free up the French and Low Countries' rail networks for troops and other war materiel closer to any planned date.

Then again...

A "long" Sealion date allowed the Germans to identify and muster and convert specific classes of barge they wanted to use; there' were PLENTY that weren't mustered, alot of smaller barges and wooden construction ones for example. It would be possible to muster a similar carrying capacity rapidly - just not have them as well converted or of as sturdy construction. But the Germans were always prepared to countenance that - look at the veritable sh1t they sent the Crete convoys to sea in!!!

2/ An "early" date means that there's no delay brought on in mustering the Rhine barges by the RAF's attacks on the Dortmund-Ems Canal in July IIRC the destruction eventually wrought held up the muster historically for some three weeks!

And of course 3/ an early Sealion date means that the British coastal defences are, in many of the locations the Germans planned to land...really quite bad!

One of things to remember is - when we look at the efences as they remain today, we're seeing the remains of nearly a year of preparations; the British started work again in the winter of 1940 and early Spring of 1941 to continually improve what they began in a panic under Ironside in late May 1940...

This is where you need to read Newbold

 

Well....the Norway example would indicate that finding and destroying the KM at sea may NOT be quite as successful or as complete as people assume!

Thing is....an "early" Sealion date means that all manner of German "side shows" are still in the plans, like the Scotland/Firth of Forth diversion...which the Home Fleet are going to have to find and wrap up BEFORE tackling the rest of the KM in the southern part of the North Sea, screening the northern entrance to the Narrows.

Historically, for the "long" Sealion date - they did; they actually had concrete and timber left over once they finished the conversions!

The problem for the attackers - I.E. the RAF or FAA - is that by the time it's light enough for them to attack any incoming bagres - they're virtually aground anyway, within a mile or half mile of the shore.

They were actually much stronger, although they weren't originally converted for that The Germans not only poured concrete ballast and reinforced this with railway rails etc. to provide decking for vehicles etc, as I noted before they reinforced the hull sides internally with quite heavy timber, 12-18 inches thick.

 

If this is the correct book the price doesn't look too bad:
http://www.amazon.com/Sprawling-Wargames-Multiplayer-Wargaming-Griffith/dp/1445202999/ref=sr_1_1?s=books&ie=UTF8&qid=1399291975&sr=1-1&keywords=Sprawling+Wargames
~$20

 

It doesn't look to me like the OP thought that was a given. On the other hand the LW achieved local air superioirity over parts of southern England on multiple occasions. Achieving it wasn't that much of a problem. Holding it for long enough to launch an invasion on the other hand was.

Well most reasonable people would suggest the same or at least that the Germans would have concluded the same. Temember they thought througout the BoB that they were on the edge of succeeding. However the OP doesn't seem to be of that opinion.

But the Germans really can't start such a ccampagin like this against the RAF until mid June at earliest and likely sometime in July before they are really in a position to do it. In the mean time the RAF is indeed ramping up. Is one month enough time to accomplish what they need to do, realize it, and launch an invasion? Indeed is it even enough time to plan out in any detail said invasion?

I would think if it's light enough for the paratroopers to be dropped anywhere close to their intended targets and land safely then it would be light enough for British fighters to attack the transport planes. It would to a large extent come down to just what the RAF decided to concentrate on though.

 

Correct; the third (and last!) day of ops against RAF radar stations comes to mind...when the Germans were able to insert large raids through the gaps resulting in the first and quite damaging raids hitting several airfields...the second being the aforementioned last week in august/first half-week pf September when they "opened" their path to London and operations in the Biggin Sector were greatly impaired.

One thing often missed is that the early-BOB wrinkle of the number of fighters that could be controlled by the Sector control rooms being limited by the number of HF channels available for the task severely restricted the ability of Fighter Command to reinforce specific Sectors in extremis; one of the major charges laid on Douglas Bader's conduct was that by taking his squadron "Jerry hunting" down on the coast he not only left the airfields he was supposed to be protecting wide open to attack...which happened!....his squadron's presence over the South Coast overloaded the available number of dedicated Sector HF channels and they couldn't control their OWN squadrons effectively!

The conversion to VHF was only half-completed by the end of August IIRC; in JULY therefore, it would be entirely possible for the Germans to overload the command-and-control capability of Fighter Command in specific Sectors...forcing the RAF to instead fly on standing patrols and pre-issued orders, with only a minimum of that "ground controlled interception" that acted as a force multiplier for them

The Luftwaffe commenced what later became known as the Kanalkampf within three weeks of the Armistice I.E. very early July - hence the July 10th start date for the Battle of Britain It didn;t JUST involve attacks on Channel ports, Channel convoys etc. to bring up Fighter Command for the "freehunting" 109s to engage...it ALSO involved a wave of more "strategic" operations, including the attacks on Southampton and Supermarine, Hawker and Vickers at Brooklands etc....

The interesting thing is that the Luftflotte commanders began this part of the campaign without any real input from Goering! basically, as John Ray notes, noone told them NOT to continue the war against England....so they did!

And of course - it also shows that the LW only needed three weeks to fully relocate to France and the Low Countries and commence a respectable sortie rate.

As noted above and elsewhere - Fighter Command was in a parlous state after France - not just the losses of Hurricanes in the original BEF Air Element/ Advanced Air Striking Force...but the subsequent losses of Spitfires over Dunkirk AND over the front line during Fall Rot They were flying combat sorties over the front line there...then ON to refuel and re-arm and Rennes, and BACK to Kent and Sussex via the front line again....but taking considerable losses.

Dowding kept Eleven Group up to strength by transfers in from other Groups...but it meant that if a focused LW campaign had been launched in July....if Goering hadn't been such a dilletante about it for virtually all of July!...it would have faced a Fighter Command without much "depth" of resource behind Eleven Group for a number of weeks...

It also doesn't help that early-BoB Fighter Command tactics and forward dispersals too close to the coast resulted in a pretty even loss rate during the kanalkampf. In fact, in many encounters during July the RAF came off worse than the Luftwafe!

The first wave was to drop two minutes after sunrise!


EDIT: One thing I've always been interesting in finding out was how "dawn's" atmospherics interfered with RDF....or not, of course

Because SOMEHOW the LW was always able to insert "weather flights" over the UK very early in the morning...and it was a long time before Fighter Command started flying standing patrols early enough to get enough altitude on them for interception...

 

So the Germans have less than 3 weeks to "destroy the RAF", realize they have done so, and launch the invasion. Doesn't sound very likely to me. It's also still not clear that they have the sea lift available to make a serious impact even by the end of July.

So the transport planes would have been fairly visible for half an hour or more prior to that. I would think that they would be a high priority target for the RAF and given their previous usages an expected one.

 

Aircraft flying at relatively low altitude in poor visibility don't make for good targets Or to be specific - much slower targets flying at c.800 feet against blacked-out terrain in half-light...!

There's no sign that the RAF ever expected to operate against an airborne attack, or expected to STOP one...given the amount of preparations carried out on the ground against a paratroop attack I'm not sure they would fritter away their fighter strength against them anyway - the LAST thing that Fighter Command needs to be doing is returning to its airfields to refuel and re-arm when the full weight of the Luftwafe arrives!

Also - the British would have no inkling of any such operation anyway EXCEPT by extrapolation....dare they hope that the Germans would be as predictable as to carry out the SAME operations for the third time in a row???...unless the Luftwaffe starts making its preparations by radio Even then the unfortunate thing however is that on the eve of the start of the BoB in July, we were only reading 35-40% of LW radio intercepts; the situation had greatly improved by the end of the summer.

Interestingly - even when the British came to know relatively full details on Sealion towards the very end of August, they still didn't include that early-light operation against Ju52s into Fighter Command's list of priorities!

To be fair - the Germans didn't wait on destroying the RAF at any point in 1940 before starting preparations for invasion As for realizing they had done so - "Beppo" Schmidt would be telling them they had, even if they hadn't!

The question is - do they NEED the same scale of capability in early to mid-July as they would do later in the summer, once British defences are better developed and the British have far more reliable indicators of German intentions and where?

I'll have to dig out my copy of Macksey and see what he says; he does have a tendency to chop facts around in brewing his "July" landing scenario - a bit like Peter Jackson and JRR Tolkien's conversation content! - but a lot of his material is very accurate, just....misplaced

 

I guess there are multiple possibilities:

• In April 1940, Ultra information provided a detailed picture of the disposition of the German forces, and then their movement orders for the attack on the Low Countries prior to the Battle of France in May.
• An Ultra decrypt of June 1940 read "The Cleves Knickebein is directed at position 53 degrees 24 minutes north and 1 degree west". This was the definitive piece of evidence that Dr R V Jones of scientific intelligence in the Air Ministry needed to show that the Germans were developing a radio guidance system for their bombers. Ultra intelligence then continued to play a vital role in the so-called Battle of the Beams.
• During the Battle of Britain, Air Chief Marshall Sir Hugh Dowding, Commander-in-Chief of RAF Fighter Command, had a teleprinter link from Bletchley Park to his headquarters at RAF Bentley Priory for Ultra reports. Ultra intelligence kept him informed of the German strategy, of the strength and location of various Luftwaffe units and often provided advance warning of bombing raids (but not of their specific targets). These contributed to the British success. Dowding was bitterly and sometimes unfairly criticized by others who did not see Ultra, but did not disclose his source.
• Decryption of traffic from Luftwaffe radio networks provided a great deal of indirect intelligence about the Germans' planned Operation Sea Lion to invade England in 1940 and, on 17 September 1940, about its cancellation.
• An Ultra message reported that equipment at German airfields in Belgium for loading planes with paratroops and their gear was to be dismantled. This was taken as a clear signal that Sea Lion had been cancelled.

It is hard to see, how, with the notorious Luftwaffe signals discpline, how a Fallschirmsjäger assault in July wouldn't leak out, or at least be highly suspected.

And what would differentiate a collection of Ju-88 transporters organising themselves into formation over Calais from a collection He-111's plus escorts doing the same on the Chain Home network? Of course, IF the Ultra failed to pick up the increased threat of Para-invasion, then Home Chain would be ineffective in differentiating the purpose. We can't assume that it would be standard practice to approach at low level already all the way from their bases in Belgium, surely?

 

...which shows the sort of difficulty with relying 100% on decrypts - you see PART of the picture and if you want the rest or corroboration you have to rely on other sources. If you care to read Newbold he discusses in some detail how the picture of German intentions was built up...and even as late as September 5th there was no clear 100% indication that their target was the South Coast of England.

Here's an example...

...IIRC this message wasn't received until partway through October.

It refers to a ramp and roller system that the LW had for loading small boxes etc, up over the wings of Ju52s and into the side cargo doors; as of the "current" ausfrung of Ju52, the cargo door hadn't yet been stretched back past the edge of the main wingspar.

....Beause the FJ themselves were pretty good with their signals discipline; it was the rest of the Luftwaffe that was crap! Looking at Goetzel's comment in Lucas' "Storming Eagles" a lot of the preparation and planning of the FJ's part was done face-to-face and by people actually going and doing stuff. Like Goetzel going and finding accomodation and storage in Northern France and Belgium himself for FJ and their kit rather than tasking someone to do it by wireless message In this sort of circumstances there's not much actually DONE via radio!

And as noted - there's the whole aspect that the British were still only reading a percentage of LW wireless transmissions in July....a smaller amount of signals' traffic referring to Sealion, together with a smaller percentage being successfully decrypted at the time, means there's a lot for the British to miss.

That's the point - there's absolutely NOTHING differentiating a formation of LW bombers from a formation of LW transports...except perhaps the latter wouldn't spend "painting" time on RDF formating and waiting for fighter escorts? It needs the good old "Mark One eyeball" to make the call on what type of aircraft they are...in the half-light of dawn...by which time, given that their jump zones are SO close to the coast, its far too late anyway.

The other side of the problem is that the actual landings on S-Day were to be preceeded by c.three days of LW bombing of the "coastal crust" and obvious defences. Whatever's left of the RAF's RDF network would be EXPECTING to see a mass of aircraft formating over France and the Low Countries...for the third or fourth day in a row

800 to a thousand feet, say? (The FJ jumped at 800 feet at that time) Why not? Plus the majority of their departure fields were in Northern France; we're not actually talking very far from there to Lympne/Folkestone....

The main temporary storage space arranged for FJ kit by Goetzel just happened to be in the vicinity of Laon...and given the major Armee De L'Air airfield there, at Laon-Cambry later used by the LW during the Battle of France, we can use that field as a "milepost".... so we're talking one-way distances of only c.150 miles, a round trip of c.300.

...which is a further advantage for the Luftwaffe; unlike Norway, and Holland, and later Crete - it's a pretty short distance for damaged transport aircraft to have to recover back to friendly territory.

 

In one of these conversations someone once made the point of both the British and the Germans using the open air transmissions from the planes as a signficant source of tactical intel. Apparently when forming up there was quite a bit of chatter. How much this would impact things is an open question.

As far as sea lift goes if the Germans don't have the barges they will be extremely limited but they can move a lot faster. If they are using barges, especially for the inital landings, then the speed of the barges is likely to tellagraph the fact that the operation is under way.

 

You're talking....on the British side,...about the "Y Service" ....

Thing is, by the start of the historical BoB I.E. July 10th...ALL it consisted of was a new base at Fairlight, East Sussex, and six (6) idiomatic/regional German speakers installed there was intelligence gatherers. It was still a really quite small operation at that point.

It SOON expanded - they could hear LW pilots talking about the number of aircraft in their formations, their destinations, their fields of origin etc....but it's questionable if it could have contributed much from a standing start in the event of a July Sealion. It's just going to be overloaded with unprocessable data!

The RAF did use the intel to try and target LW airfields...but the campaign was hopeless; out beyond fighter escort range, the Blenheims sent to attack German airfields were under orders to abort missions if there wasn't enough cloud cover to allow them to approach and exit the target safely; at least 95% of these missions were scrubbed beause of that requirement (according to the raf.mod.co.uk site)

If anything, the GERMANS got the most out of SIGINT! It did take them quite a while, but they did in the end get their heads around the idea of Ground Controlled Interception

 

I understood that the FJ bases were actually in Belgium. Rather than just opposite Dover. Makes sense given the longer range of the transports, compared to the fighters.

 

Well, technically what makes sense is that the fields they were using weren't ideally the same "front line" ones as for the air battle as of S-Day...because the constant stream of transports coming and going...and possibly blocking them temporarily due to wrecked/damaged arcraft making it back across the Channel...would make any other use of the fields the FJ was using next to impossible. Ditto for why they had to use makeshift airfields in Greece for Crete - Richthofen's fighter aircraft had to use the developed ex-Greek airfields, while the Ju52s used the "scratch" airfields.

Also - don't confuse "bases" and "airbases" Goetzel was reconnoitering transit accomodation and storage in Belgium and Northern France for only the 24-48 hours before S-Day...and he also drew up a very well-timetabled and detailed movement plan for shifting 7th Flieger and 22nd Luftlande forward to them from their barracks in Germany at the last minute.

 

While most of the British army units in the UK were under equipped they still had enough to defeat any forces the German's were capable of landing in the first few days.

http://www.wwiiequipment.com/index.php?option=com_content&view=article&id=125:british-equipment-losses-at-dunkirk-and-the-situation-post-dunkirk&catid=50ther-articles&Itemid=61

 

...which figures unfortunately vary considerably with David Newbold's

 

I finished reading Michael Glover's "Invasion Scare 1940" today; it's been hard wading through it, he's an anti-Sealion partisan..anti the whole idea, plays up Hitler's reticence - and Churchill's using the threat of invasion to firm up British morale after Dunkirk. It's pretty excreble book, I honestly considered consigning it back to the 2nd hand bookshop after some thrity pages after some of the GLARING errors and downright lies I found LMAO He's not afraid to twist bits of evidence and facts into whatever shape he wants to support his argument...

In the last chapter, discussing more the aspect of Hitler's delays in planning - he notes that the order to gather shipping and barges wasn't given formally until July 8th...

If it had been given earlier, the Germans would have had the historical September carrying capacity earlier, if the order had been given, say, before the beginning of Fall Rot, or at the Armistice - 3-4 weeks earlier. his BIG decision was robbing German industry of the barges' carrying capacity - AND...

Where did Hitler get all the merchant shipping that was to be used for Sealion? They had 21 to loose during the bargebusting, for example, but plenty more to hand...

Simple - he halted ore shipments from Sweden!

All the shipping used for THAT trade was diverted temporarily to Sealion. If Sealion had been successful the war would have been virtually won - well, literally won! And it wasn't as if much could be produced that would swing the result of Sealion during the weeks it would take...so no point in continuing the trade at the time!

I'll have to check Kieser, but IIRC the majority of the barge conversions were ready FOR September I.E. by very late August...which means seven weeks maximum for the full force. the first two weeks in September were for repositioning the barges/ships at their jumping-off ports. Advance preparations by 3-4 weeks, and you could just about scrape the last weekend in July for the full capacity....sooner for less...