operation sea lion

[mkloby]

Supress the enemy with heavy fire, then send some troops round the flank to blast their hopelessly exposed be-hinds. Or something like that.

That would be the idea behind fire and maneuver.

This has gotten off of Op Sea Lion - back onto topic. Sorry.

Civitonne, it doesnt matter how many divisions the Germans had. The size of the sealift and capacity of your logisitics that dictates how many divisions are available for invasion and then follow on.

After D-Day, even with the vast number of landing craft and transports available to the allies, only a division every two days were landed. And that was also with total and absolute control of the sea and air 24/7. Something problematic with the Germans.

Now look at your Germans invasion scenario's. Just exactly how many troops could be landed on the beaches with enough firepower to stay, and then build up forces faster than the Brits can contain them or throw them into the sea.

Sys - do you, or anybody else, know of any statistics pertaining to the number of troops that Germany could have logistically sustained in a cross channel invasion?

 

[HealzDevo]

Yes, and the Germans didn't really have the ability to throw into the mix a lot of naval support. So how would they have been able to protect their troops from things such as MG Bunkers, etc. considering how limited their troops would have been? I mean take the 50 best divisions and you still have to get them onto the British beaches and provide support for them so that they can accomplish their task. I mean the Normandy Invasion involved 47 divisions and then they got reinforced as they swept through France and into Germany. In this it is Germany with 50 divisions, leaving 100 behind and hoping they don't get chopped to pieces...

 

[mkloby]

Yes, and the Germans didn't really have the ability to throw into the mix a lot of naval support. So how would they have been able to protect their troops from things such as MG Bunkers, etc. considering how limited their troops would have been? I mean take the 50 best divisions and you still have to get them onto the British beaches and provide support for them so that they can accomplish their task. I mean the Normandy Invasion involved 47 divisions and then they got reinforced as they swept through France and into Germany. In this it is Germany with 50 divisions, leaving 100 behind and hoping they don't get chopped to pieces...

One thing the german plans demanded was air superiority. I think the Goering predicted 4 weeks from eagle day the RAF would be effectively downed. Not to mention only German air power could keep the Royal Navy at bay to defend against their interference with a landing. I'm sure the German high command planned on business as usual with Ju 87s providing some of the best CAS around.

 

[HealzDevo]

Still there is a limit to the ability of aircraft to provide good support against certain targets isn't there? Also this fails to take into account that if the Allies lose air superiority, you can bet that every AA gun they have will be pointed up at the sky or even tanks being used for AA if the plane is flying low enough...

 

[Civettone]

Good discussion guys!

mkloby, I understand that the 3:1 advantage is advisable and as such still very useful. But you seem to be making it into something it isn't: a rule. The 3:1 advantage seems to be the ideal scenario. But like I said before, most succesful offensives in WW2 did not have a 3:1 advantage. In fact, very few did...

Syscom, I didn't say the Germans would have landed 50 divisions. I said they would use at most 50 divisions. This was a reply to someone wondering if Germany would have had enough troops available for the invasion. I said they would use maximum 50 divisions...
I was thinking of landing 5 divisions, and 2 new divisions a day. This would have meant 15 divisions in a week. After this more resources would have to go to supply and only 1 division a day could have been moved.
At least this was the idea I had in my head. Your comment that the allies could only bring in 1 division every two days makes me wonder if my idea is still valid.
There are some small differences beween the two though. Allied shipped much more supplies and vehicles to Normandy, basically building up a force which could advance quickly once broken out. German planners also calculated less tons of supplies needed for a division than for instance Americans did.
What was the reason the allies managed to bring in so many troops in the first 24 hours and brought in so few in the following days?

The Germans did the channel dash, what makes you think the British wouldn't do the same thing to smash an invasion force.

Glider, battleships are too slow and cumbersome to operate in the Channel. They are too exposed to operate in such a small area. That's why the Channel dash was so exciting. Now can you imagine the Tirpitz sticking around for a couple hours in the Channel? No, it's not called the dash for nothing, you know? She was a sitting duck and the fact that the Luftwaffe was able to protect her was an extraordinary feat!

Shipyards are a different thing entirely

In 1943/44 the Germans managed to triple submarine production without diminishing production for the other two military branches. German shipyards were very ineffective compared to allied shipyards until Speer and Dönitz took over.

Lenningrad isn't the same as the channel, its bigger wider with more currents, plus how are you going to lay the many thousands of mines when the RN rule the sea and have literally hundreds of minesweepers.

It's not possible to seal off the Channel although the Germans would have tried. Fact remains that it would have been a dangerous place for the RN.
I disagree with your point on the minesweepers. Minesweeping is a time consuming activity. If the Germans would have started a nocturnal mine dropping campaign few weeks before the invasion, the Royal Navy would not have the time to clean as fast as the Germans could lay mines. I'm talking about thousands and thousands of mines.
And don't forget the German subs...


A final note and one which I have repeated a couple of times: people are constantly referring to D-Day as if this was the 'canon' of invasions. I don't see why the Germans needed to have the superiority of the allies of 1944, if British defences were not like the German defences of the Atlantikwall either. Plus, German invading divisions would have been superior to the defending British forces as they would receive the best men, leaders and equipment.

Kris

 

[HealzDevo]

Yes, they would but still they would have to overcome the English fighting spirit. England was not about to roll-over and quit. You point out that those divisions would have the best leadership, equipment, etc. but there was only one design that I have seen for tank transport. Therefore the German forces would have been relying on air support to destroy the British infantry tanks, etc. before the British destroyed them with those. CAS would have become very tricky if the British had deployed a lot of their AAs and tanks to that sector. No low flying and high flying would have become tricky due to AA concentration so where does that leave the German Luftwaffe?

 

[mkloby]

Good discussion guys!

mkloby, I understand that the 3:1 advantage is advisable and as such still very useful. But you seem to be making it into something it isn't: a rule. The 3:1 advantage seems to be the ideal scenario. But like I said before, most succesful offensives in WW2 did not have a 3:1 advantage. In fact, very few did...

It is not a rule, and I didn't intend that in my posts. It comes from a doctrine involving attacking, as stated above, with a overpowering forces. I wouldn't say that all offensives enjoyed a 3:1 advantage, but many of the offensives that did have a sharp advantage in manpower/materiel were successful. Also, overall manpower in totality is not the same as an operational advantage. You can concentrate mass and acheive an advantage in a given operational sector. A good example of that is the Fall Gelb and the 44 Ardenne Offensive, although the Battle of the Bulge ultimately failed for the Germans. Speed also has an effect, and it serves as a force multiplier. It's entirely more than tallying up troop numbers on each side of an operation.

This was brought up in the thread a while back on amphibs, but what about the poor state of the British Army following Dunkirk, and the tremendous losses in equipment and materiel. Estimated left behind at Dunkirk were: 2,500 guns, 84,500 vehicles, 77,000 tons ammo, 165,000 tons gasoline, and 416,000 tons of supplies.

The British Army must have taken a considerable amount of time to re-equip and stand up these units as capable fighting forces. Also, reinforcements would not be able to be brought to Britain from the Empire if the Battle of Britain went as planned for the Germans.

Yes, they would but still they would have to overcome the English fighting spirit. England was not about to roll-over and quit. You point out that those divisions would have the best leadership, equipment, etc. but there was only one design that I have seen for tank transport. Therefore the German forces would have been relying on air support to destroy the British infantry tanks, etc. before the British destroyed them with those. CAS would have become very tricky if the British had deployed a lot of their AAs and tanks to that sector. No low flying and high flying would have become tricky due to AA concentration so where does that leave the German Luftwaffe?

I would tend to think the stategy would be to initially capture a port, largely intact if possible (not that the British would allow that) to reduce rebuild time, and use ships to unload the majority of heavy equipment, men, and materiel.

 

[syscom3]

Syscom, I didn't say the Germans would have landed 50 divisions. I said they would use at most 50 divisions. This was a reply to someone wondering if Germany would have had enough troops available for the invasion. I said they would use maximum 50 divisions...

Think.... how were those divisions going to be staged, transported to the UK , off loaded without the benefit of a port, and then resupplied?

I was thinking of landing 5 divisions, and 2 new divisions a day. This would have meant 15 divisions in a week. After this more resources would have to go to supply and only 1 division a day could have been moved.

Work out the math. There simply wasn't enough shipping and landing craft available for the Germans to succede. And where do you propose to station all those landing craft?

There are some small differences beween the two though. Allied shipped much more supplies and vehicles to Normandy, basically building up a force which could advance quickly once broken out. German planners also calculated less tons of supplies needed for a division than for instance Americans did.

History is littered with the results of Military expeditions that failed because of lack of supply and underestimating consumption rates.

What was the reason the allies managed to bring in so many troops in the first 24 hours and brought in so few in the following days?

It was a matter of landing enough forces to establish a beachhead and then follow up with the supplies later. Plus there weren't any armoured divisions put ashore untill the next day. And those types of divisions take up lots of shipping.

Glider, battleships are too slow and cumbersome to operate in the Channel. They are too exposed to operate in such a small area. That's why the Channel dash was so exciting. Now can you imagine the Tirpitz sticking around for a couple hours in the Channel? No, it's not called the dash for nothing, you know? She was a sitting duck and the fact that the Luftwaffe was able to protect her was an extraordinary feat!

If an invasion was immenent, the RN would have sacrificed caution to the winds, and attacked the invasion forces.

It's not possible to seal off the Channel although the Germans would have tried. Fact remains that it would have been a dangerous place for the RN.

And for the KM. Danger works both ways.

I disagree with your point on the minesweepers. Minesweeping is a time consuming activity. If the Germans would have started a nocturnal mine dropping campaign few weeks before the invasion, the Royal Navy would not have the time to clean as fast as the Germans could lay mines. I'm talking about thousands and thousands of mines.
And don't forget the German subs...

And where are all the German warships and invasion craft going to come from to provide fire support? Or are your forces just going to take their chances without sea and/or air support?

A final note and one which I have repeated a couple of times: people are constantly referring to D-Day as if this was the 'canon' of invasions.

Actually operations Olympic and Coronet were going to be even larger. And provide us with an example of an amphibious invasion that was even remotely the size and complexity of Overlord.

I don't see why the Germans needed to have the superiority of the allies of 1944, if British defences were not like the German defences of the Atlantikwall either.

The British in 1943 had all the advantages of fighting on home ground on interior lines of communications with an immense (and I mean IMMENSE) US war machine ready to go to battle. The Luftwaffe was far from dominate in 1943. They had no heavy bombers, to bust up the UK ports and airfields, the Spitfire was supreme and that doesnt take into account the USAAF aircraft that would have gotten into the fight and shredded the LW and KM.

If you want an invasion in 1944? Forget it. Theres nothing in the German war machine to match what the allies could put out.

Plus, German invading divisions would have been superior to the defending British forces as they would receive the best men, leaders and equipment.

Any examples of this alleged superiority?

 

[HealzDevo]

The German Tank superiority by 1941/1942 was that they had swept across in tanks that were meant to be training tanks for their armies. Tanks such as the Panther would have been a big handful to transport across the channel.

Also the Germans would have been landing in an environment that would be hostile to them. The beachs were heavily mined, some beaches were designed to go up in flames, AA was set up in strategic areas. In addition they had the home guard which had a whole bunch of tactics which might have been effective in doing serious damage to the Germans...

Also does this include the RAF reserve aircraft which would have been thrown into the fight to stop the Germans? You can be sure that in this case every single machine that was airworthy in the whole of Britain would have been sacrificed to stop the Germans.

 

[Jabberwocky]

To successfully launch Sealion you need these preconditions:

1. Defeat the RAF, FAA and Costal Command as offensive air arms of the UK military (not necessarily the same thing as defeating them).

2. Prevent or delay the RN from carrying out offensive and defensive operations in home waters.

3. Isolate the 3 beachhead areas to allow for the unimpared landing of troops and supplies

Those are pretty lofty goals, just to LAUNCH the operation, let alone conduct it sucessfully.

To sucessfully carry out the invasion you need to:

1. Land your chosen amount of assault formations (original plans is 1-2 1/2 airborne/gliber divisions, supported by lead echelons of a further 4-6 divisions).

2. Supply your chosen assualt formations (assumed MINIMUM rate of 300 tons of supplies per division per day for an infantry division and approximately 25% more for a tank division)

If the initial landing is successful, then you'll need to:

3. Land your second echelon and explotiation formations as well as motorised transport

4. Supply your second echelon and exploitation formations

Given the physical limitations of materiel build up, transport capacity and supply capacity, its a tough ask unless you can dedicate approximately 24 months to building a small boat fleet and destroying the RAF and RN wholesale.

This is also ignoring operations conducted by the enemy to interrupt your assault, supply and explotiation operation.

Unlike the British on Crete, or the Germans in Normandy, the Germans are presented with a more complex tactical picture:

They ha ve no control of the skies, and at best aerial parity, so landing paratroopers and glider formations is risky at best, especially given the rise in RAF night fighter operations after September 1940 and the continued application of RADAR to anti aircraft gunnery in the same period (even though it wasn't really operationally effective until mid-1941).

They have no control of the water. At best they are outnumbered about 5:1 in surface combatants and have a 2:1 advantage in submarines, and the RN continued to experiance favourable exchange ratios whenever it faced the Kriegsmarine in a straight fight right through the period.

Without control of the water, assault operations are risky and supply operations are essentially out of question as a practical enterprise.

They have no control of the battlespace in the UK. The Germans have no method of preventing large scale formations of the British Army assembling, manouvering and striking at their leisure. They have not cut rail and road links and the aerial assault is aimed at capturing inland airfields (cutting it off from the main assault), not preventing the movement of British reinforcements.

The seaborne assaults were aimed at the densest concentration of British fixed defences (the British essentially having guessed correctly), designed to slow but not stop attackers (unlike the 'Atlantic Wall'), while the Army assembled to strike weighted blows against the assault formation.

 

[mkloby]

1. Defeat the RAF, FAA and Costal Command as offensive air arms of the UK military (not necessarily the same thing as defeating them).


Unlike the British on Crete, or the Germans in Normandy, the Germans are presented with a more complex tactical picture:

They ha ve no control of the skies, and at best aerial parity, so landing paratroopers and glider formations is risky at best, especially given the rise in RAF night fighter operations after September 1940 and the continued application of RADAR to anti aircraft gunnery in the same period (even though it wasn't really operationally effective until mid-1941).

They have no control of the water. At best they are outnumbered about 5:1 in surface combatants and have a 2:1 advantage in submarines, and the RN continued to experiance favourable exchange ratios whenever it faced the Kriegsmarine in a straight fight right through the period.

Without control of the water, assault operations are risky and supply operations are essentially out of question as a practical enterprise.

They have no control of the battlespace in the UK. The Germans have no method of preventing large scale formations of the British Army assembling, manouvering and striking at their leisure. They have not cut rail and road links and the aerial assault is aimed at capturing inland airfields (cutting it off from the main assault), not preventing the movement of British reinforcements.

I disagree with your condition of defeating the offensive capablity or british air assets. The goal of the Germans following the BoB was to destroy British defensive air assets, and take air superiority. By the nature of that, British offensive capabilities to strike German operations would in turn become extremely costly sorties given German control of the air - specifically over the south of England.

If this condition was met, Germany would have air supremacy. German air assets would make RN operations extremely dangerous and likely suffer catastrophic losses if attempts were made to challenge landings.

Also - why would Germany have no capability to conduct any Deep Air Support?

 

[Glider]

Good discussion guys!

I was thinking of landing 5 divisions, and 2 new divisions a day. This would have meant 15 divisions in a week. After this more resources would have to go to supply and only 1 division a day could have been moved.

Glider, battleships are too slow and cumbersome to operate in the Channel.

In 1943/44 the Germans managed to triple submarine production without diminishing production for the other two military branches. German shipyards were very ineffective compared to allied shipyards until Speer and Dönitz took over.

It's not possible to seal off the Channel although the Germans would have tried. Fact remains that it would have been a dangerous place for the RN.
I disagree with your point on the minesweepers. Minesweeping is a time consuming activity. If the Germans would have started a nocturnal mine dropping campaign few weeks before the invasion, the Royal Navy would not have the time to clean as fast as the Germans could lay mines. I'm talking about thousands and thousands of mines.
And don't forget the German subs...

Kris

Kris
Your right this is a good debate and taking the points one at a time

2 Divisions a day for a week
A weeks good weather in the channel is close to a miracle. Even if the weather stays mild the sea conditions don't. Without the weather you would have huge trouble getting anything across without a proper port.

Battleships are to slow and cumbersome for the Channel
Actually there not. The opening stages of the Battle of Britain were German attacks on the convoys going up the channel. Most of these were colliers carrying coal for the powerstations on the Thames. Despite their best efforts the Germans never stopped a convoy of large, slow (3-5 knots) unmanouverable, almost unarmed colliers. Certainly some were damaged and some sunk but despite a number of attempts they never stopped a convoy.
If you cannot destroy a target like that, what makes you think that you can stop a naval fleet intent on attacking a landing area that they know is likely to be the make or break factor of the war. More than enough would get through.

Submarine Production
They did more than triple production but only at the cost of the production of almost any other major shipping project. If you want to build landing forces the point I was trying to prove is that something, in this case submarine production, would have to go.

Nighttime Minelaying
The Channel at night belongs to the RN. We had far more ships, the men and the knowledge (most officers in small forces were amateur sailors who knew the coast). We also had radar direction of those forces. If the Germans had tried to depend on nighttime minelaying then they would have lost. The Germans never dominated the Channel at night. The minelayers would have been attacked and enough of the mines swept.

Submarines in the Channel
This never worked at any time in WW2 and equally never in WW1. The currents are very strong, the tides are amongst the biggest in the world and the sands the most dangerous. The average high tide is about 17ft and at the likely landing grounds the tide goes out about 2/3rds of a mile. Obviously this depends on the landing site but at Southend its over a 1 1/4 miles.

 

[Udet]

I must insist: do you forget what the conditions of the British Army in England were during 1940?

The BEF had virtually lost all its equipment: tanks, artillery, vehicles and supply stocks, not forgetting the British soldiers dead and captured in France. When they were allowed to escape all they brought with them was their wet clothing.

How is it that i read comments pointing out the fact the divisions landed ashored by the Germans would have endured "very high losses"?

You are not going to compare what the Brits could have oppossed to meet a German invasion -not intended- in 1940 with what the Germans had available to throw against the allies on June 6th, 1944 are you?

I had suggested the very idea, but Mr. Civettone came to correctly elaborate further on that: why do you think Germany needed a "D-day" type of display to successfully land and smash the British in England?

 

[Civettone]

So many reactions to respond to... I'll do my best.

Let me start by saying that what I have in mind is a Sealion in the Summer of 1942, after defeating Russia in 1941. This is not a rule - that's not up to me - but that's what I have in mind when I make these comments. So that means half a year of preparations in which production of all kinds of aircraft and naval transportation devices are being build. I would expect the Germans to prepare for the invasion for half a year, gathering information and drawing up extensive plans. This is all meagre compared to what the allies had in 1944 but as I said before, it doesn't have to be like D-Day. Germany could do with less.

I've read many references to D-Day like destroying of infrastructure, controlling the skies, etc. I think D-Day is such an icon because it was so incredibly succesful! When you look at it, it was almost a walk-over. Now before you start throwing things at me, let just look at the numbers until the end of July: 50,000 dead out of 2 million men. On D-Day itself 2,500 dead, most on Omaha beach. So besides Omaha beach, D-Day was a walk-over. That's what excellent preparation and numerical superiority lead to.
But if only half of these advantages were there, I still think D-Day would have succeeded. Not one of the beaches was a failure, not one was evacuated. Even if the allies had just one or two beaches in their hands, they could stil have won the battle and go on to break out of Normandy.

I don't see Germany achieving superiority in the air, on the ground or at sea. But I do see them having control. And I believe this would have been enough to succesfully invade Britain, hold the beaches and eventually break out and defeat the English.

Let's break this down to those three fields:
Air: if Germany ever had better aircraft than the British it was in 1941/1942 with the Fw 190 and Bf 109F, both of which were superior to the Spitfire V or Hurricane II. Spitfire IX only appeared in the late Summer and in small numbers. British hardly had any attack aircraft, they were stick Blenheims, Beaufighters, no Typhoons or Mosquitos.
With increased aircraft production - as said above - and with most aircraft pulled back from Eastern Europe and with better pilots than the British (because of superior training hours), Germany would have held the advantage in the air. With the British aircraft primarily attacking targets in the Channel and over the German held beaches, they would no longer have the advantage of flying over friendly territory. Naturally, the Germans would have had the advantage. After a while Germany would have broken the back of the RAF in a battle of attrition like it itself had undergone in 1940.
Oh yes, I forgot to mention that I do not think it would have been a good idea to start an extensive air offensive before the invasion. That would have failed for the same reasons as in 1940. Surprise would have to be on the German side: paradropping at night and landing the first wave at dawn.

Sea: Although the Channel could not be sealed off, it could have been made difficult for the RN. Sealing off the Channel does not mean mining the Channel itself but the access lanes towards it creating a almost sealed-off area in which the Kriegsmarine and German transport vessels can operate. These mines will be dropped at night by subs and aircraft. (I just found out that wargames conducted at the Royal Military Academy Sandhurst in 1974 concluded that it would have taken a few days before the fleet would have arrived coming from Scapa Flow.) On their way they will be attacked by German bombers and submarines, and hindered by extensive mine fields and agressive German Kriegsmarine maneouvres. The Royal Navy will not be able to get to the Channel in strength on the first day and will offer itself piecemeal to all those hundreds of German Stukas and Ju 88s. When the main fleet will arrive from Scapa Flow the German divisions will have increased and have dug in for the awaited British assault, while being supplied by air. Although I see the RN cutting supplies for the German beachhead and attacking it, I wonder how long the Royal Navy would be able to witstand the damage German bombers will inflict on them? It will be a trade off between defeat of the Royal Navy or the defeat of the German invasion army. What will be easiest to rebuild? The Germans had a hundred other divisions... For that reason I don't think the Royal Navy will be holding out for longer than 2 days after which they will count their losses. 2 days in which the elite German divisions will have to hold out. I think this will be the defining moment and IMO it can go both ways, depending on the decision of the British leaders.

Ground: The German army was overall better trained and more experienced than the British. This advantage can hardly be overestimated. As only few divisions will be needed at first, they can be equipped with the best weapons available. I'm especially thinking of the superior 75mm AT and tank guns, tapered guns with the otherwise rare tungsten cored ammunition. German forces in North Africa have shown that they can push back or at least hold against a larger CW force opposing them.
So perhaps 15 divisons after a week is too optimistic. 10 divisions after a week, opposed to 30? British divisions?

So that's what I have in mind when I talk about a German invasion. I'm sorry that I'm lacking the time to reply to the many posts. I have tried to answer some of them by restating my views more extensively. I know that these are my own views on "how I would 've done it!" and based on my own thus limited views on the military capabilities of both countries. But as this is a what-if scenario, my guess is as good as any other
Kris

 

[Glider]

I must insist: do you forget what the conditions of the British Army in England were during 1940?

The BEF had virtually lost all its equipment: tanks, artillery, vehicles and supply stocks, not forgetting the British soldiers dead and captured in France. When they were allowed to escape all they brought with them was their wet clothing.

How is it that i read comments pointing out the fact the divisions landed ashored by the Germans would have endured "very high losses"?

You are not going to compare what the Brits could have oppossed to meet a German invasion -not intended- in 1940 with what the Germans had available to throw against the allies on June 6th, 1944 are you?

I had suggested the very idea, but Mr. Civettone came to correctly elaborate further on that: why do you think Germany needed a "D-day" type of display to successfully land and smash the British in England?

The German Army didn't have the ability to bring any Tanks, Artillery, trucks in any numbers with them so the ground war would have been a lot more even than you think.
Thats after the significan losses would heve been incurred on the way over. Crete was taken (just) by airbourne forces but all the naval landings were decimated at sea, despite the Germans having all the advantages.

 

[Glider]

early 1942 is an interesting period and well chosen.
There is no doubt that the 190 was the best fighter in the air by a clear margin or that the British GA aircraft were generally outmoded. It was a period of change in the RAF with P51's starting to be introduced together with the Typhoons, Mossies, Bostons and Lancasters. Daylight raid would still have been undertaken and the RAF losses kept within limits by the simple fact of being over our own territory, but the loss ratio would be in favour of the Germans.
I don't think training is an issue as by that time I believe that the RAF had inproved its hours.
There is one huge advantage the RAF had, which I hadn't thought of before. By early 1942 we had a very large heavy bomber force. The landing sites would be on UK soil, close to our bases (in heavy bomber terms) and easily identified. They would have been plastered at night at little risk to themselves.
Beaufighters would have been able to intercept the german nightfighters and operating on their own turf under radar control. German nightfighters would be operating over the UK on their own at a serious disadvantage.

RN
Again I see the night belonging to the RN, our coastal forces are large by this time and dominating the seas around Britain at night. Nothing the Germans could do wold change this.
By day Germany still would have had a lot of trouble stopping a determined attack. Losses even serious losses may be caused by air attack but like the Germans in the Channel dash, the cover would be organised. It should be remembered that a few detroyers could cause significant damage, a couple of cruisers would cause havoc and if its make or break time for the war, the losses would be accepted.

Army
The British Army was much better prepared in 1942. Equipment shortages a thing of the past. German tanks had an advantage certainly, but the fighting in the UK would be different to Russia and the Desert. Ranges are a lot shorter and most German tanks PzIII and Pz IV would be vulnerable to the 2pd and 6pd guns used by the British Army.
Artillery is an area that would come into play and was a strength of the British Army. Germany would be very limited in what they could bring over and would be outclassed/outnumbered.

PS you still haven't said what will carry the German Army and where they would be built

 

[Jabberwocky]

So many reactions to respond to... I'll do my best.

Let me start by saying that what I have in mind is a Sealion in the Summer of 1942, after defeating Russia in 1941. This is not a rule - that's not up to me - but that's what I have in mind when I make these comments. So that means half a year of preparations in which production of all kinds of aircraft and naval transportation devices are being build. I would expect the Germans to prepare for the invasion for half a year, gathering information and drawing up extensive plans. This is all meagre compared to what the allies had in 1944 but as I said before, it doesn't have to be like D-Day. Germany could do with less.

They would have to do with less.

If they defeated Russia in a 6 month campaign, the Germans then have 3-6 months to transfer their aerial forces and prepare them for an offensive campaign (assuming a start to operations between March and June 1942).

The German army has 3-7 months to prepare, given that the latest date for the original Sealion was the end of September .

Compare this to the 2 years of planning and 18 months of preparation carried out by the Allies before D-Day, with a significantly larger economic base.

I've read many references to D-Day like destroying of infrastructure, controlling the skies, etc. I think D-Day is such an icon because it was so incredibly succesful! When you look at it, it was almost a walk-over. Now before you start throwing things at me, let just look at the numbers until the end of July: 50,000 dead out of 2 million men. On D-Day itself 2,500 dead, most on Omaha beach. So besides Omaha beach, D-Day was a walk-over. That's what excellent preparation and numerical superiority lead to.

D-Day was a success because of several factors.

1. The complete aerial interdiction of the Coetetin penninsula and Normandy, combined with complete aerial control

2. The complete control of the sea and supply lanes by Allied naval power.

3. The ability of the Allies to land 8 complete divisions in the first 2 HOURS of the assault (including 3 airborne divisions).

3. The fragility of the German defences (stiff resistance at only 1 of the 5 beaches).

Total D-Day casualties were around 11,000 (including 2,500 killed), while the Allied landed approximately 160,000 thousand troops.

But if only half of these advantages were there, I still think D-Day would have succeeded. Not one of the beaches was a failure, not one was evacuated. Even if the allies had just one or two beaches in their hands, they could stil have won the battle and go on to break out of Normandy.

The single greatest worry for Montgomery and Eisenhower was that the beacheads remained unlinked or 'reduced' on D-Day. If the Germans had reduced the beacheds from 5 to two, I suggest that the operation would of been called off on D +1, as the tactical picture for the German army would of been IMMENSLY simplified.

I don't see Germany achieving superiority in the air, on the ground or at sea. But I do see them having control. And I believe this would have been enough to succesfully invade Britain, hold the beaches and eventually break out and defeat the English.

Let's break this down to those three fields:
Air: if Germany ever had better aircraft than the British it was in 1941/1942 with the Fw 190 and Bf 109F, both of which were superior to the Spitfire V or Hurricane II. Spitfire IX only appeared in the late Summer and in small numbers. British hardly had any attack aircraft, they were stick Blenheims, Beaufighters, no Typhoons or Mosquitos.
With increased aircraft production - as said above - and with most aircraft pulled back from Eastern Europe and with better pilots than the British (because of superior training hours), Germany would have held the advantage in the air. With the British aircraft primarily attacking targets in the Channel and over the German held beaches, they would no longer have the advantage of flying over friendly territory. Naturally, the Germans would have had the advantage. After a while Germany would have broken the back of the RAF in a battle of attrition like it itself had undergone in 1940.

Operating over British territory, with the British calling the shots on interceptions and able to assemble and guide their forces uch like the Germans did over France in 1941, the Spitfire V would of been on a much more even footing with the 109F (which is roughly equal in quality) and the 190A4/5 (which is superior).

The Typhoon Ib was in operational service by the end of 1941 and there were seven squadrons operational with the type by the end of August 1942 (Nos 266, 56, 256, 486, 181, 182 and 609).

Similarly, the Spitfire Mk IX began entering service in July, and there were 4 squadrons (Nos 64, 611, 401, and 402) operational by the end of August.

The other advantage the British have is a more than tripling of the strenght of Anti-Aircraft command by the end of 1941 (figures taken from 'Ack-Ack', by General Frederick A Pile, Commander in-Chief of Anti-Aircraft Command):

June 1940 ADA Defensive guns

Heavy:

4.5 inch: 355
3.7 static; 313
3.7 mobile: 306
3 inch (obsolete): 226

Light:

40mm Bofors: 273
2 lbr: 140
20mm: 38
3 inch (obsolete): 136

Dec-1941:

Heavy:

4.5 inch: 476
3.7 static: 935
3.7 mobile: 465
3 inch (obsolete): 144

Light:

40mm Bofors: 1,056
2 lbrs: 71
20mm: 62
3 inch (Obsolete): 8

Plus, AACommand had introduced radar azimuth and ranging detectors, essentially doubling their effectiveness in terms of accuracy and battery fire control.

Oh yes, I forgot to mention that I do not think it would have been a good idea to start an extensive air offensive before the invasion. That would have failed for the same reasons as in 1940. Surprise would have to be on the German side: paradropping at night and landing the first wave at dawn.

And what happens on the second day, when an undiminished RAF strikes the German beachheads and the supply ships anchored of the coast waiting to unload?

Coastal Command is hardly impotent, with low level Hampdens, Bostons, Beaufighters and Whitleys to hit the Kriegsmarine.

The RAF is going to have a dream scenario carpet bombing the invasion beaches while Hurribombers go in at low level.

Sea: Although the Channel could not be sealed off, it could have been made difficult for the RN. Sealing off the Channel does not mean mining the Channel itself but the access lanes towards it creating a almost sealed-off area in which the Kriegsmarine and German transport vessels can operate. These mines will be dropped at night by subs and aircraft. (I just found out that wargames conducted at the Royal Military Academy Sandhurst in 1974 concluded that it would have taken a few days before the fleet would have arrived coming from Scapa Flow.) On their way they will be attacked by German bombers and submarines, and hindered by extensive mine fields and agressive German Kriegsmarine maneouvres.

You are forgetting serveral important parts of the British defensive plans: the light costal forces and submarines and the RNs own minfields.

The RN had approximatley 80-120 light coastal boats in Home Waters at any one time. Unlike their German counterparts, British light boats had radar and were trained to operate both at day and night. Anti invasion plans were to strike at the Kriegsmarines escort ships initially with Motor torpedo boats in the day (which were not as good as German E-boats) and then disrupt landing and resupply operations with Motor Gun Boats at night.

British submarine forces would of had a field day: tightly packed, slow moving assault craft guarded by destroyers while the big ships (crusiers and battleships) rides shotgun, attempting to picket the RN.

The Royal Navy will not be able to get to the Channel in strength on the first day and will offer itself piecemeal to all those hundreds of German Stukas and Ju 88s. When the main fleet will arrive from Scapa Flow the German divisions will have increased and have dug in for the awaited British assault, while being supplied by air. Although I see the RN cutting supplies for the German beachhead and attacking it, I wonder how long the Royal Navy would be able to witstand the damage German bombers will inflict on them? It will be a trade off between defeat of the Royal Navy or the defeat of the German invasion army. What will be easiest to rebuild? The Germans had a hundred other divisions... For that reason I don't think the Royal Navy will be holding out for longer than 2 days after which they will count their losses. 2 days in which the elite German divisions will have to hold out. I think this will be the defining moment and IMO it can go both ways, depending on the decision of the British leaders.

The RN had a saying around the battle of Crete "It takes three years to build a ship, it takes three centuries to build a tradition".

The RN may be damaged, even heavily, but neither the LuftWaffe or the Kreigsmarine are going to go home intact either.

The ability of the Luftwaffe to destroy the RN, while stationary and evacuating troops at Dieppe (6 destroyers over 10 days, including 2 torpedoed and one mined) and Crete (2 cruisers, six destroyers) seems a little overrated to me.

You haven't granted control of the skies to the Luftwaffe, and the RN would be operating in home waters, under the umbrella of an undiminished RAF operating over 100 squadrons of fighters. The RN would harely be prey to hordes of bombers.

More tommorow....

 

[syscom3]

Dont forget the USN was going to contribute quite a few warships to the frey including a couple of carriers.

Interesting scenario.... Daunteless's going after German warships protected by Wildcats. ME-109 vs F4F.

The US could also contribute some fighter's (P40's and maybe a P38 group). And unlike the BOB in 1940, there were plenty of allied pilots available to make good any loss's.

I wish you would get off this idea that you could transport 15 divisions within a week. Its impossible. Period. Try 5 - 6 divisions of light infantry IF the channel remains calm and youre extremely lucky and the Brits/US extremely unlucky.

Lose a port and forget about landing heavy eqmt in numbers and in a hurry. Its highly unlikely that the KM could design and build enough heavy amphib ships within 1/2 year.

Even if this invasion did take place, it was going to be a disaster for the Germans after one week. Not enough logistics, not enough time, not enough air/sea support when needed.

 

[Civettone]

Ok, now for some seperate points.

About Germany not being able to bring in two divisions a day because the allies couldn't bring in more one every two days. My answer is I don't know why the allies couldn't bring in more. The explanations I've heard so far are unconvincing. If it was because the allies started to bring in more tanks, fuel, supplies and vehicles (like happened in Anzio) then I feel assured that I'm not thinking of bringing in Panzerdivisionen or the extra fuel and supplies they needed.
But I still don't understand that the allies manage to bring in 10 divisions in the first 24 hours and after that only 0.5 divisions in 24 hours. Someone care to explain? I'm puzzled.

About German bombers not being able to sink ships. Especially the case of Dunkirk comes to mind but it is often misquoted. Only a part of the Luftwaffe in France was used near Dunkirk. The battle against France was still going on and bombers were also needed elsewhere. Add to that the relatively high losses the German Luftwaffe had already suffered. The bombers were putting too much effort on the beaches and the actual embarking. Yet, it's clear that more could have been achieved. To explain this, one has to remember that German crews were not trained in attacking naval targets. This only started after the BoB after which results improved. I can provide numbers if needed but look at Crete for instance where 10 warships were destroyed by German bombers. Or Pedestal where (mainly) German bombers sunk about 5 ships of a one-way convoy towards Malta. These were all long-range missions. Bombers operating from the Calais area could attack and return to base in half an hour. British fighter interceptors would no longer have the advantage of early warning as they had in the BoB: they would come too late to scramble and intercept bombers attacking targets in the Channel. So let's say we'll have 10 times the number of bombers of Pedestal (100x10) able to fly 5 missions a day (not unusual for a short period, see Kursk) and carrying a much larger bomb load (1000 kg armour piercing bombs!), that means 50 times the sorties of Pedestal but with more bombs. So that would lead to 250 RN ships destroyed and many more taken out of action in a single day. Let's keep in mind British fighter CAPS (though this will mean they won't escort their bombers as they attack the invasion beaches), atttrition, fatigue, bad weather, bad luck, and detract half: that would still mean 100 destroyers and cruisers lost and many more taken out of action a day!
Add to that: German mines, submarines, surface ships and coastal guns.

Mines: The Sandhurst war games acknowledged that German main fields could have seriously hindered the RN advance. I believe that the Royal Navy ruled at night, just look at how they defeat the Regia Marina at night. But it's not like they had complete control. This is shown by the fact that the Germans were indeed able to mine the area (though not as much as they could have if they wanted to), even today there are still German mines washing up on British, French or Belgian shores. Coastal submarines anyone? German fast S-Torpedoboats which formed a danger up to May 1944 (remember their attack on the allied invasion fleet exercise?). So add those threats to the Royal Navy and I believe anything between an absolute minimum of 100 warships a day could be sunk and a maximum maximora of 300 ships taken out of action, ... a day.

I believe it was Jabberwocky who said the Bf 109F was on equal footing with the Spitfire V. This was not the case. There's only one aspect in which the Spitfire V was better and that's firepower. Speed, climb rate, acceleration, agility are all in favour of the Friedrich. Plus, up to early 1943 Germans had better pilots than the British (for every German fighter they lost they shot down three British, at the end of 1943 this had turned the other way around!). I already said the Typhoon and Spitfire IX would have only been available in small numbers. Especially the Typhoon was plagued with problems and only got their act worked out in 1943. Up to 1942 they were still thinking of pulling the plug on it. I'm sure you're aware of this. I can also understand that you wanted to leave that out
In combination with the Typhoon discussion ... although the British AA capability had increased, they had little to throw in against German Fw 190 attacks ... until the Typhoon started to intercept them in early 1943. That says a thing or two about British AA warfare.
But even then, I don't think it will be that much of an issue. If you read my posts, you'll notice that I'm digging in 'my' German infantry and using all my bombers to take out the Royal Navy. This will result in the entire RAF fighting over hostile territory and the disputed Channel.

Ground. Not much to add to that. I also don't see many comments on that subject. Only want to add that the 6 Pdr was still rare in the Summer of 1942. Standard AT gun was still the 2 Pdr. I'm sure the British would have had fun using that against the latest German tanks. The advantage of the better German guns is not range, it's penetration values. The 75mm could penetrate every British tank (exception perhaps the rare Churchill tank) while the vast majority of British tanks still had 2 Pdrs.

In case I forgot to answer to someone's comment, please remind me of them. Right now, my fingers are starting to ache...

Finally I would like to stress yet again, that in my scenario the Germans would have devoted half a year of preparations to the invasion. Although that's not as much as the allies had for D-day, I think this could have been enough preparation (I mean, why would D-Day be the standard??) and would have meant German manoeuvres, war games, tactics, training, intelligence, and their own Hobbart-funnies to be developed. This Sealion 42 can hardly be compared to that of Sealion 40.

Kris

 

[HealzDevo]

But then there are too many assumptions still there, which I feel need to be challenged. First of all, how are they planning to do any better in their analysis of the RAF fighter strength than before? It was proved that the German kills were too high, and keep in mind that they wouldn't know still at this stage just how far their kills were over reality. Also I know you are also using the Kriegsmarine but this assumes that the Kriegsmarine has enough firepower to support the German troops and help them establish themselves. As we know there are questions of the availability of this firepower.