Another Sealion Thread

Sorry for taking two of your statements together Glenn but they illlustrate a point, Hitler had driven germany since 1933 and taken a enormous series of risks in doing so. He was not a coward or an accountant.

Hitler himself stated to the effect he was a lion on land and a coward at sea.

Why then did He blink at Sealion, did he see it as unachievable?

Because Hitler wanted to attack the USSR.

I Think that he did not think it was worth the risk, he did not see the reward as worth the attempt. He dismissed Britains ability to make war thinking he could settle affairs with the Russians before Britain could be a serious threat.

That may be so, but Hitler is long dead. It is us now. We have a better idea of the risks to not trying Sealion. Had Hitler known in 1940 about the scale, for example, of strategic bombing by late 1944, he'd have invaded Britain.
 
Okay, let's grant for a moment that

1) the Luftwaffe can win the battle in the air, knocking out enough of Fighter Command to make them withdraw from Southern England's airfields, without the LW itself being crippled.

So we have a damaged LW which has to maintain the following tasks:

a) maintain superiority over the RAF.
b) degrade the Royal Navy's ability to interfere with the landings and supply convoys.
c) disrupt the British Army's ability to fight, to move, and to co-ordinate against landing beaches.

You've got the priority list backwards. Picture the defences to Sealion as three legs of a stool - the RAF, the RN and the British army. Now, remove the RAF completely. Pretend not one plane existed in Britain. That's bad, but the RN and British army could still defeat the invasion, right? Now, remove the RN - no ships. Dicier, but the RAF and British army can still defeat the invasion, right? Now, remove the British army. That's checkmate. Without a British army there is no concievable way to defeat Sealion. Britain will fall.

The British army is the key leg of the stool. That is the point that obsession with the RN always misses. If the British army fails, Sealion will win the war. If the British army succeeds, Sealion is thrown back.

So the operational objectives of the Luftwaffe during are backwards to what you wrote; c,b,a
As far as I can tell, that is an impossibly tall order - remember that this is a force which OTL failed to achieve just point a) - and I know Iain argues it was an impossibly close run thing; perhaps - so the Luftwaffe was narrowly insufficient to deal with the RAF on its own.

Think of Sealion as an invitation to the Royal Navy to prove that it can sink as many ships and do as much damage as you think it can. Sort of a put up or shut up call to some boasting claim. Don't forget that the ditches of history are paved with navies that failed to perform at crunch time.

As the Atlantic campaign showed, it is harder to defend a convoy against attack than to attack one; there are more RN warships than KM, and the RN warships have more heavies.

As many WW2 convoy battles showed, it could prove very difficult for warships superior in numbers and firepower, even in perfect visibility conditions, to translate their advantage into heavy enemy losses when attacking convoys. And that was true even later in the war when ships fighting at night could actually see in their environment with radar. Here, you're asking the RN to fight blindly at night with nothing but luck and some starshells against smoke screens and other visibility impediments.

The effect of the RN would probably be more to break up the organisation of the invasion fleet than do heavy attritional damage.

In this instance, where the targets are barges, and most of the defending ships S-bootes or smaller, a "heavy" is probably a destroyer and up. Now imagine the carnage when a destroyer with 4 4.7" QF guns, and 10 torpedo tubes gets within striking distance of unarmoured barges?

At night without radar pretty much 99% of all ammunition fired is going to hit nothing. If the RN destroyers were to close to point blank (where their guns could hit maybe with 10% of their shells) then they are also within lethal radius of the embarked guns of the invasion fleet.

I've seen Slapton Sands mentioned - there really is no comparison between an S-boot (2 torpedo tubes and a 37mm gun if it's lucky) attacking LSTs (Landing Ship Tank), and an I-class or up destroyer attacking Rhine barges.

During WW2 the Allies and Axis fought dozens of small sea battles using small ships and destroyers, kind of like a potential Sealion battle. In practically NONE of them, despite fire control radar and better intel, did Allied destroyers approach ANYTHING LIKE the kill ratio being glibly assumed here.

Do you have any idea how hard it is to see something like a barge at night at sea? And that doesn't assume Murphy - fog, smoke screens, or good old fashioned smoke from burning ships and gun cordite.

The LST is about ten times the displacement of a barge (4.8kT against ~.5kT, as far as I can tell), and the destroyer easily 5-times as well armed as the S-boote.

Think of S-boats something like the Ajax and Archilles at River Plate. The Exeter, (ie, the barge fleet) is wounded and helpless. The Graf Spee (ie, the RN destroyer) is trying to concentrate on sinking the Exeter. The light forces are hounding it, distracting it, preventing it from acting, causing it to be inefficient.

Or in other words, where 9 S-boote sank 2 LSTs and damaged 2 more, I would expect 9 destroyers to sink more like 100 barges and damage perhaps 100 more.

Before calling kill rates of 20:1, you might actually want to take a look at the dozens of night destroyer sea battles in WW1 and WW2 to see what sort of average kills rates were actually generated. For example, 3 Austrian cruisers in 1917 managed to sink 14 out of about 50 small lighters on the Oranto Barrage. Their "poor" performance was a result of the fact that they actually had to go out in the middle of the night and find these tiny boats, then manage to fire enough shells to sink them. I imagine that if the Austrians were fighting the Oranto Barrage on the internet, their cruisers would have posted a result of 50 kills.

And Glenn, you keep talking about how it will be a major win for the Battle of the Atlantic even if Sealion is tried and failed; it will, for the Allies. Do you expect the Kriegsmarine to be able to avoid committing U-boats to support the landings?

The RN might lose 60 destroyers in a Sealion campaign -sunk or badly damaged. The German navy lost 6 U-boats in the Norwegian campaign. That looks about right for Sealion.
 
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katchen

Banned
Care to give any example of a commander who applied your logic in history?
I think I can. Vo Nguyen Giap in his 1975 invasion of South Vietnam. He attacked Ban Me Thuot knowing that if the South Vietnamese were reinforced by the United States he would lose a lot of men and have to withdraw. But Congress banned aid to South Vietnam and President Ford went along with it instead of attempting to subvert Congress's intent with the help of foreign allies.
Possibly Chu Teh or Lin Piao in the Huai Valley offensive of the Chinese Civil War 1948.
 

Re: Luftwaffe priorities – the trouble is, that the Luftwaffe OTL were putting in maximum effort to defeat the RAF and failing. So, even assuming for the sake of an ATL they have temporarily suppressed Fighter Command, they aren’t going to have substantial forces spare for any other purposes; and if they aren’t conducting naval strikes the landings can’t take place at all.

Which brings us to the naval side of things; given the extent to which the Luftwaffe will be stretched, and the failure of the Luftwaffe in attacking light ships under way, there is no reason the RN cannot attack the invasion convoys in daylight; this is why I never specified that the RN would be attacking the invasion convoys only at night.
During the Dunkirk evacuation, which took over a week, nine Allied destroyers were lost in total. Of those, only 5 were lost to air attack; and of those five, as far as I can tell, at least three were impaired in their manoeuvring by being inside the Outer Harbour, laden with hundreds of evacuees, or taking a sister ship under tow. One particular case, HMS Basilisk, took three separate air attacks before she was too damaged to be salvageable and destroyed by HMS Whitehall.
The Luftwaffe does not possess a serious anti-shipping capability, and the Stukas which can hit destroyers are vulnerable to fighters and going to be in extremely heavy demand for hitting land targets as well.
This is why all your assumptions about night-fighting are irrelevant. The Luftwaffe will not be able to prevent the RN operating in the Channel in broad daylight; the KM won’t be able to do much to the RN at all; the guns mounted on invasion barges are going to do nothing against destroyers (they might be able to damage an MTB or MGB which gets too close, but not a destroyer).
Additionally, your consideration of “dozens of small sea battles” or “dozens of night destroyer sea battles” isn’t hugely useful. I don’t think any of the historical examples show warships outnumbered 3 to 1, escorting vital transports, attacking into the teeth of a prepared enemy who knows they’re coming. There are 10 KM destroyers in commission. There are nearly three times that many RN destroyers available and tasked to deal with invasion barges, ignoring any others which might be diverted to this duty if an invasion is actually in progress. A fight between 25 destroyers which want to cause carnage, and 10 which are trying to defend vulnerable barges, is very different from a fight between unattached destroyers in open water, though you don’t seem to appreciate this.
Essentially if the KM destroyers come out to play, they’ll get roughly handled, and the remaining RN destroyers (most of them) will go to work on the invasion barges. It shouldn’t take more than a few salvos of 4.7” shells to wreck a barge pretty well; add in torpedoes and they’ll be blowing up left and right.
If the KM destroyers don’t come out to play, then the Heer and Luftwaffe claim their plans were perfect and the Navy’s cowardice caused it to fail.

If the RN lose more destroyers in the Great Channel Turkey Shoot than they did in the Dunkirk Evacuation, I would be amazed.
 
Re: Luftwaffe priorities – the trouble is, that the Luftwaffe OTL were putting in maximum effort to defeat the RAF and failing. So, even assuming for the sake of an ATL they have temporarily suppressed Fighter Command, they aren’t going to have substantial forces spare for any other purposes; and if they aren’t conducting naval strikes the landings can’t take place at all.
Here is a slightly different view on things.

The trouble is, that the Luftwaffe OTL were putting in maximum effort to defeat the RAF and failing - The Battle of Britain as it became known was far more complex than winning or losing. During July 1940 and the into the first week of August the Luftwaffe had two objectives, the first was to clear the English Channel of shipping and the second was to tempt the RAF fighters into the air where they could be reduced in strength prior to a full scale attack. The Germans succeeded in the first aim, the British closed down the channel to coastal convoys and stopped using Dover as a destroyer base. Whilst sinking 65 ships and damaging 68 others the battle in the air raged above the convoys and the harbours with the Luftwaffe losing close to 320 aircraft with the RAF losing just over 190 (plus 120 or so damaged). If it hadn't have been for Britains excellent production rates the second object to reduce the RAFs fighter strength would have also been achieved. As it was fighter command managed to increase its reserve of aircraft to 400 or so by the start of the next phase of battle.

During the next phase of the battle the Luftwaffe started badly but by 6th September had brought fighter command almost to its knees. The attacks on airfields, radar and factories put fighter command under a great deal of strain and attacks on shipping still went on but now the priorities were changed ... weaken the RAF first and keep the ships out of the Channel second. In total over 50 frontline fighters were destroyed on the ground between 13th August and 6th September almost 20% of all losses. In addition to that dozens of other aircraft were destroyed on the ground in other raids like the ones at Driffield on 15th where 10 aircraft of bomber command were destroyed and a further 5 damaged or the raid on Brize Norton the day after which destroyed 36 training aircraft and 11 Hurricanes at Brize Norton being repaired. Not including those lost on the ground the RAF lost a further 380 fighters in the and over 200 damaged, adding up to a grand total of over 630 aircraft put out of action in less than a month. Effectively the entire strength of fighter command had to be replaced in just one month which they managed to do but the reduction in the reserves was very alarming, although the Luftwaffe lost 660 aircraft as well. In addition to this the shortage of pilots mean that pilots were transferred from bomber and coastal command and even from the FAA meaning that each of these air arms would be short of pilots to mount anti-invasion sorties if Sea Lion was ever launched.

Fortunately for fighter command the Luftwaffe changed targets on 7th and the next phase of the battle began. The losses of aircraft dropped down to a managable level of just under 250 destroyed (with none on the ground) and just over 150 damaged. This effectively meant that the reserves of aircraft were being built up once more.

Interesting to note that the ratio of destroyed aircraft in the first two phases was around the 1.5-1.6 LW aircraft lost for every RAF fighter lost rising up to 1.9 and beyond after the switch of targets. In hindsight the Germans statistically should have continued what they were doing.

they have temporarily suppressed Fighter Command - In my eyes there is no temporary supression of fighter command. Once fighter command starts to decline it continues to decline, there would be no position of recovery without a major German cock-up or the cancellation of the attacks. Once the Germans have the upper hamd they will keep pressure on the British until the day of the launch of Sea Lion. The attacks continue on fighter command from 7th to 14th September by which time they are sufficiently weakened that attacks on RN targets can begin weakening both the RAF who try to protect the Navy ships and also on the RN themselves. The attacks on the RN continue for a further ten days then Sea Lion is launched ... then anything can happen ...

Obviously all of this is in hindsight looking at the statistics it is touch and go as to who would have triumphed in the Battle of Britain and victory in the Battle of Britain does not mean the Germans can suppress the RN or be in a position to launch the invasion. But by switching targets on the 7th the Germans threw that chance away.
 

hipper

Banned
they have temporarily suppressed Fighter Command - In my eyes there is no temporary supression of fighter command. Once fighter command starts to decline it continues to decline, there would be no position of recovery without a major German cock-up or the cancellation of the attacks. Once the Germans have the upper hamd they will keep pressure on the British until the day of the launch of Sea Lion. The attacks continue on fighter command from 7th to 14th September by which time they are sufficiently weakened that attacks on RN targets can begin weakening both the RAF who try to protect the Navy ships and also on the RN themselves. The attacks on the RN continue for a further ten days then Sea Lion is launched ... then anything can happen ...

Obviously all of this is in hindsight looking at the statistics it is touch and go as to who would have triumphed in the Battle of Britain and victory in the Battle of Britain does not mean the Germans can suppress the RN or be in a position to launch the invasion. But by switching targets on the 7th the Germans threw that chance away.


Hi Ian I now have the figures

The quick summary is that the GAF had 560 deliveries of single engined fighters during August and September while the RAF had 1301 spitfires and hurricanes delivered in that period.

For the week after the 7th September the Germans flew substantially fewer sorties than the previous week I believe this had a large affect on the number of RAF losses.

However I suspect from the figures that the airfield attacks impared the repair of aircraft on the squadrons which was the greatest effect of the german attacks on the sector airfields.

I'll write up the figures on a bigger post. But I don't believe continuation of the airfield attacks would have been decisive.

Cheers Hipper
 
Re: Luftwaffe priorities – the trouble is, that the Luftwaffe OTL were putting in maximum effort to defeat the RAF and failing. So, even assuming for the sake of an ATL they have temporarily suppressed Fighter Command, they aren’t going to have substantial forces spare for any other purposes; and if they aren’t conducting naval strikes the landings can’t take place at all.

Assuming Sealion had actually gone forward, the RAF would not have been surpressed. As both land and sea tasking would have been of higher import during the invasion, it follows that the RAF would have been put at the bottom of the priority list.

Which brings us to the naval side of things; given the extent to which the Luftwaffe will be stretched, and the failure of the Luftwaffe in attacking light ships under way, there is no reason the RN cannot attack the invasion convoys in daylight;

Please cite historical examples where surface combat forces successfully pursued offensive missions under constant air attack.


During the Dunkirk evacuation, which took over a week, nine Allied destroyers were lost in total. Of those, only 5 were lost to air attack; and of those five, as far as I can tell, at least three were impaired in their manoeuvring by being inside the Outer Harbour, laden with hundreds of evacuees, or taking a sister ship under tow.

The Luftwaffe launched a grand total of about 1,900 bomber sorties at Dunkirk and about 250 Allied boats and ships were lost to all causes. To say that 'only' 9 destroyers were lost implies indirectly that the Luftwaffe was 'only' attacking RN warships, when the kills stats from Dunkirk indicate that the majority of bomber sorties were expended on targets other than RN warships.

the KM won’t be able to do much to the RN at all; the guns mounted on invasion barges are going to do nothing against destroyers (they might be able to damage an MTB or MGB which gets too close, but not a destroyer).

Barge guns would have had little effect beyond holding the RN at longer ranges, where more ammunition would have to be used to achieve any effect. In real life vast amounts of ammunition were invariably expended to achieve anything in combat. It was not unusual for even quick engagements to eat up 25%

Additionally, your consideration of “dozens of small sea battles” or “dozens of night destroyer sea battles” isn’t hugely useful.

The bulk of such experiences seems to point to an overall level of lethality to warships in combat as far lower than you would assume.
 
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