operation sea lion

[Civettone]

We've been through most of what you said though they are still good points. You're right about it being impossible to keep the invasion secret. I acknowledged this in my last post.

I like your idea of a pre-emptive strike. It's quite likely the British would go at it if they would think the invasion was imminent. But as the night bombers were unable to destroy the ships in the drydocks of Brest, I don't see them achieving much against the invasion fleet. So they would have to go at it during the day. But all I have to say is: Channel Dash. 250 German fighters managed to hold off 75 RAF squadrons. British fighters were good but their day bombers were aweful. In the end, a pre-emptive strike would weaken the British FC, BC and RN while the Germans could still postpone the invasion by a day (or two).


Even though the British would know of a future invasion and would photograph the Germans assembling their forces near the ports, they would still be uncertain about the actual D-Day. Everyone would expect the Germans to start an air offensive first (like in 1940). The embarking itself would have to happen under the cover of darkness and like the Channel Dash the British would perhaps only find out that the invasion fleet was underway once it was already in the Channel. The Germans were no fools and would know how to keep a lid on the operation.
And besides that, the English still didn't know where the Germans would land!

The only thing I really disagree with is what you're saying about the Americans. They were building up their army as fast as they could. Sending in non-operational divisions for a possible German invasion in the future would not happen. They would only send them if the invasion had actually taken place, ready or not.
Kris

 

[syscom3]

In 1944, the Germans managed to get a few E-Boats in amongst an American amphib training excersize near Slapton Sands and savaged the US ships.

That was a good example on how these small patrol boats would savage the German amphib ships in 1942. All it takes to throw an invasion into chaos is for a few PT boats to run amok.

 

[bigZ]

Wouldn't Bletchley Park be able to blow the lid on an operation in 42?

 

[renrich]

BigZ very good point. Of course!

 

[Glider]

Let me try and sum things up.

TanksGermany had no LCT or designs and would not be able to bring any on line with only 6 months. A 6 month timescale is impossible, no country ever managed this not even the USA.
Result
As a result the Germans wouldn't be able to use Tanks or other large transport.

Building an invasion fleet
Submarines were built in prefabricated sections but were assembled in shipyards. You still need to work out where the invasion ships are going to be built. You either replace the Submarine production, or the minesweeper programme. S Boats are different and are built in boatyards not shipyards as they are only around 125-150 tons.
Result
Something has to give either the U Boat or Minesweepers both critical to the success of the invasion

Protecting the Invasion (air)
Using the Channel Dash as your example. 250 planes defended 2 modern, well armed, fast BC's who were running, not hanging around to fight. How many would be needed to defend an entire invasion fleet(s) if your landing in more than one place, spread over many miles over a period of days. Remembering that the invasion fleet are slow large, ill armed targets.
The Channel dash wasn't attacked by 75 squadrons, had they done so then they would have gone down by weight of numbers. An invasion fleet would have been attacked with everything in our airforce and the defences swamped.
The 109 was equal to the Spit V, the 190 clearly better, but the 190 was a small minority of the force available. Also the Germans would have to spend longer over the target to defend it. The RAF would be able to launch hit and run attacks and escape if the fighting got too hot. Very similar to Dieppe. The RAF would be more numerous than the Germans at Dieppe.
Result
Losses would be high on both sides and the German losses to the invasion fleet serious.

Defending the Invasion (Sea night)
If the Germans land the German Navy is not going to defend the beaches at night but stay in French waters coming out when the advantage is on their side. This wouldn't happen. The German vessels would be open to interception and attack on the way over.
Result
The Invasion beaches are wide open to attack and bombardment by night.

Defending the Invasion (Sea Day)
The RN is more than willing to take serious losses to hit the invasion force because if we lose, the war is over.
The German Navy cannot face the RN by day so must rely on the GAF. As explained this will have to cover the invasion fleet and attacks on the RN. The RAF will be able to distrupt these attacks due to the points above ie quality of the planes and the numbers. German bombers are the same as in the BOB. They may have some more armour and carry a larger bombload but the Spits now have 20mm not LMG and the German bombers still have a similar performance as before. When attacked they will suffer badly. Minelaying will be countered to some extent by the distruption of the minelaying and the minesweepers available to the RN.
Result
RN losses would be significant but managable. Germany never stopped a convoy with air attack alone, why should they destroy a Naval attack that can form up at night and launch the attack at daylight. In a similar manner no submarine ever operated in the channel with any success or stopped a Naval Fleet, why should they now.

Heavy Bombers
These would pulverise the landing area at night. To argue that we couldn't hit the landing area which would be miles across, because we couldn't hit the German BC's in dock, is comparing chalk and cheese. The RAF only have to hit the landing area's not the ships. With well over a thousand bombers available (Hampdens and Hudsons up to Lancasters) there is no reason to doubt that the RAF could launch 300 to 400 bomber sorties a night, every night with little loss to themselves. German nightfighters will be operating on their own without radar control and the RAF Beaufighters were as good as the best and operating under their own fighter direction
Result
Anything landed would be either distrupted or destroyed.

 

[bigZ]

If the Germans did manage to invade and everything goes SNAFU. We can allways rely on these boys.

As Lance Corpaoral Jones would say ""I may be old but I can still give them the old cold steel, and they don't like it up'em, you know, they do not like it."

 

[Civettone]

Germany had no LCT or designs

Why do you keep repeating that? Germans were going to embark tanks on the barges.

You either replace the Submarine production, or the minesweeper programme.

They managed to triple production of the subs and double production of PT boats and miesweepers by using the same shipyards. So ok, now they'll just double production of subs and keep that third bit for transport boats. What's the problem?

The Channel dash wasn't attacked by 75 squadrons, had they done so then they would have gone down by weight of numbers.

The British used over 700 aircraft (amongst them 400 fighters) against 250 German fighters and achieved nothing! Their ships in the Channel achieved nothing, not even a German MTB was lost. Yet, this is going to be the force that is going to annihilate the German invasion fleet?
Scharnhorst - The History - Operation "Cerberus" - The Channel Dash

How many would be needed to defend an entire invasion fleet(s) if your landing in more than one place, spread over many miles over a period of days.

If you would have read my posts you would have seen that they would land on the first day and retreat until the Royal Navy would retreat. IMO this would have lasted two days.

The 109 was equal to the Spit V, the 190 clearly better, but the 190 was a small minority of the force available.

The Bf 109 was better than the Spit V and I already explained this. If you disagree, please tell me why and back this up with figures. I also said aircraft production would increase: more Fw 190s.

If the Germans land the German Navy is not going to defend the beaches at night but stay in French waters coming out when the advantage is on their side. This wouldn't happen.

Well, according to my plan they do.

The Invasion beaches are wide open to attack and bombardment by night.

True

The RN is more than willing to take serious losses to hit the invasion force because if we lose, the war is over.

If you lose, the war is over. Sounds logical

The German Navy cannot face the RN by day so must rely on the GAF. As explained this will have to cover the invasion fleet and attacks on the RN.

No, on the first day the Kriegsmarine will escort the invasion fleet. It could take on the MTBs and DDs during the Channel Dash so they could do it again, this time warding them off before they reach the invasion fleet. British MTBs are no match for German S-Boote (or E-boats as you call them) so you can forget Slapton Beach where the LSTs were unprotected.

Minelaying will be countered to some extent by the distruption of the minelaying and the minesweepers available to the RN.

You cannot sweep mines as fast as the enemy can lay them.

These would pulverise the landing area at night.

And what will that achieve? Strategical bombers are useless against tactical targets, especially when dug in.

To argue that we couldn't hit the landing area which would be miles across, because we couldn't hit the German BC's in dock, is comparing chalk and cheese. The RAF only have to hit the landing area's not the ships.

Reminds me of Hitler's order to have Me 262s to attack the invasion beaches. He literally said they would just fly over the beaches and drop a bomb on them. I think he would have been glad with you backing him up


Anything else?
Kris

 

[syscom3]

Why do you keep repeating that? Germans were going to embark tanks on the barges.

And just how were these tanks going to be off loaded in choppy sea's on unimproved beaches? Oh, and a minor question for you..... how many tanks does each barge carry?

They managed to triple production of the subs and double production of PT boats and miesweepers by using the same shipyards. So ok, now they'll just double production of subs and keep that third bit for transport boats. What's the problem?

The problem is you thinking the shipyards can design new ships and then mass produce them in basically a matter of weeks.

The British used over 700 aircraft (amongst them 400 fighters) against 250 German fighters and achieved nothing! Their ships in the Channel achieved nothing, not even a German MTB was lost. Yet, this is going to be the force that is going to annihilate the German invasion fleet?

Famous last words of many a combatant. They didnt touch me before, therefore they cant touch me now.

The Bf 109 was better than the Spit V and I already explained this. If you disagree, please tell me why and back this up with figures. I also said aircraft production would increase: more Fw 190s.

The -109 and -190 were not going to gain air superioity in a matter of weeks. If anything, it was the brits who were going to end up controlling the skies because they would not lose pilots like the LW would. And what will happen to your plans if the RAF decides to pull its fighters back out of range and amass its forces? Will you have air superiority on invasion day?

No, on the first day the Kriegsmarine will escort the invasion fleet. It could take on the MTBs and DDs during the Channel Dash so they could do it again, this time warding them off before they reach the invasion fleet. British MTBs are no match for German S-Boote (or E-boats as you call them) so you can forget Slapton Beach where the LSTs were unprotected.

Once again, your KM will fend off everything from bombers and the RN. You will do the impossible that the USN in 1945 was never able to do against the Japanese. Provide 100% defensive success against air/surface/sub threats without the aid of modern fire control. Even your mine sweepers will perform their duties without hindrance and 100% success. Tell us, is there anything in your scenario's that allows the RN/USN/RAF to actually inflict damage to your fleet?

You cannot sweep mines as fast as the enemy can lay them.

Exactly, which means your invasion fleet will run into the allied mine fields. Oooooppppssss.... I forgot... In your scenario, they dont work and will not impact your plans.

And what will that achieve? Strategical bombers are useless against tactical targets, especially when dug in.

But landing craft and barges massed in port and/or on the beaches are an inviting target, plus they can also easily be swamped by near misses. One funny thing about your scenarios..... if you're not bringing along trucks, have no capability of offloading from the larger ships right to inland dumps...... where are you going to store your material?

 

[Civettone]

Heya Syscom!

And just how were these tanks going to be off loaded in choppy sea's on unimproved beaches?

I don't know, I never thought about it. Didn't really see the need to question this as the German plans explicitely mention transporting tanks over the Channel. Who are we to question their ability to do so 67 years after date? They could be wrong about winning battles but I think they would know how to unload tanks from barges...

Oh, and a minor question for you..... how many tanks does each barge carry?

Well, most barges could carry at least 200 tons (the common 'Belgian' type barges). Although these could carry several tanks, they would probably only have carried one or two, and use the rest of the valuable space for lighter objects and for soldiers.

As it seems you're interested, let me also add that in 1940, they had 2,318 modified (with bow ramps) barges - I don't know how many unmodified barges - and 155 freighters (carrying capacity of totally 700,000 ton) and about 2000 auxiliary vessels, motor boats, motor sailers, etc.
All of this was apparently sufficient for their needs as Raeder told Hitler in a meeting on Sept. 15th where he advertised that the KM would be ready by the 21st [to unload 13 divisions in 3 days].

The problem is you thinking the shipyards can design new ships and then mass produce them in basically a matter of weeks.

Yeah, barges are really complex!

Famous last words of many a combatant. They didnt touch me before, therefore they cant touch me now.

I could turn that around. "You couldn't invade us in 1940, so you can't invade us now!"

The -109 and -190 were not going to gain air superioity in a matter of weeks. If anything, it was the brits who were going to end up controlling the skies because they would not lose pilots like the LW would. And what will happen to your plans if the RAF decides to pull its fighters back out of range and amass its forces? Will you have air superiority on invasion day?

You've not been reading my posts. Yet, I will reply to this. I specifically said there would not be an air campaign prior to the invasion (unlike 1940). This would surprise the British but it would also mean that the British would no longer have the advantage of fighting over friendly territory: they would have to fight over German held beaches and the Channel. So in a war of attrition the (better trained) German pilots (in better aircraft) would hold the advantage.
So no, I don't expect the Luftwaffe to have air superiority. I just expect them to have the upper hand. Superiority will come later.

Tell us, is there anything in your scenario's that allows the RN/USN/RAF to actually inflict damage to your fleet?

Read my posts. I never said the KM would not suffer losses. I'm saying it would be used on the first day before the Royal Navy would arrive in the Channel at strength, after which it would be pulled back near the safety of the French coast and only be used in a few hit and run attacks if it could get an advantage. That's not the same as the RN which would be wide open in the Channel.

Exactly, which means your invasion fleet will run into the allied mine fields.

Strange. When I mention German mines keeping the RN at bay, it's criticized. But apparently the British mines are now an unsurmountable obstacle?
What did the allies to disable the mines along the coasts of Normandy?

But landing craft and barges massed in port and/or on the beaches are an inviting target, plus they can also easily be swamped by near misses. One funny thing about your scenarios.....

Forget the swamping thing. Or do you really believe that story of wakes of a destroyer sinking barges? I said this before, but I'll explain it a bit more:
All barges had to meet following naval requirements…
- Able to handle open water up to sea state 2 [Significant wave height of 1.4 feet or 0.4 meters], which was the basic English channel sea state.
- Able to land on beaches with slope of 1 degree
- Able to transport a 25 ton tank
- Able to use all Dutch Belgian and French canals.

However the barges exceeded these figures , here's a quote from Schenk "Invasion of England 1940" Translated 1990, pp 70:

"For the first criteria it was calculated that the barges would need a freeboard of at least 2 m and would have to be in a good state of repair. As it turned out , the barges were more seaworthy than expected, shipping little water during exercise in winds of force 4 to 5 and coping well with waves. Even at wind forces of 6 to 8 only two barges reported damage to external bow doors during one exercise with the 17th Infantry Division."

if you're not bringing along trucks, have no capability of offloading from the larger ships right to inland dumps...... where are you going to store your material?

I don't know. Never thought about that. During the first days the allies stored most of their stuff on the beach.
Difference was perhaps that the Germans would have to tow it in place while the allies drove it there. That's better in the long run as you can use those trucks later on for the outbreak but a waste at first. Just look at Anzio: 17,000 vehicles for 70,000 men. Hey, you just made me realize THAT is the real difference between Allied and German landings. Thanks (I mean it!).

I look forward to your next post!
Kris

 

[Civettone]

The following is from Paul Lakowski, some of you might know him. Really interesting.

Schenk notes there were 1336 x type A1 "Péniche" barges @ 39 meters long 5 m ; wide 2.3m high , with a capacity of 360 tonnes. In addition there were 982 larger "Kampinen" type A2 barges @ 50 meters long 6.6m wide 2.5m high and a capacity of 620 tonnes [able to carry 4 tanks] .

Most barges were towed and about ~ 1/3 of these barges were already motorized with 6-7 knts speed, however it was reckoned that in some cases 30% of the barges were so old and worn as to be unusable, while the rest were damaged due to untrained crews. If this is applied across the board the 2400 barges would net 1600 usable barges of which maybe ¼ were motorized.

The historical conversion task was massive and between August and early September 2400 barges and 400 motorboats were assemble. By early September about 1269 barges were converted and by September 24th about 1552 converted towed landing barges had arrived at the embarkation points, including another ~ 330 in reserve. When the task was completed some months later the total had swollen to 1939 converted landing barges.
[P Schenk "Invasion of England 1940" , pp 65-114].

By early September at least 225 motorized landing barges had been acquired , while power units were added to another 25 towed barges. In October the Heer and Luftwaffe erected another 50-100 engineering rafts , each employing 2-3 surplus 500-750hp engines from a total of 2000 such surplus engines. These modified Sieble/Herbert Rafts could cruise across the channel at ~ 6knts and dash to the shore at ~ 10knts. Contrary to perception they apparently were quite seaworthy in coastal waters and 'the channel'.
[P Schenk "Invasion of England 1940" , pp 115-129].

The ~ 800 remaining unconverted barges were instead modified into supply barges and employed to warehouse fuel oil , diesel gasoline as well as water and other supplies. Most of these barges were powered barges that had 'broken down' and treated as towed barges. Their total load capacity was around 225,000 tons while the gross transport tankerage was 130,000 tons in 39 tankers and 75 'lighters/barges' . The expected daily consumption was thought to be about 10-12,000 tons at full strength, so on at most only 1/10th of the tankers [ 4 tankers and 7 lighters] had to cross the channel each day to feed the two armies logistical needs. [ "The Invasion of England 1940" , Peter Schenk, pp 174-175].

The barge sortie rate only envisaged the use of 2/3 of the barges on the first sortie, while a mere 400 barges were needed for each of the following 7 sorties to sustain the offensive and transport follow on waves. Since turnaround time was at best 4 days, at most 100 barges would need to make the crossing each day to sustain campaign at full strength.[ "The Invasion of England 1940" , Peter Schenk, pp 232-235].


In practice Wehrmacht logistics through out the war , were never run at full strength or anything like capacity. This rarely slowed offensives since combat doctrine and tactics were more important. While lack of logistics did crimp operations and slow tempo, it didn't prevent operations even when the delivery rate fell below 50% of capacity, as was the case when the Germans moved further and further into Russia in 1941. It was always a combination of effects that terminated campaigns against the Germans, only part of which was logistics.


50 Naval gun ships
New Zealand Coastal Shipping - Dutch Coasters
Its reported roughly 100 "Coaster" vessels were also employed in the Sea lion plan. Coasters were miniature freighters of 100-400 tons able to haul large loads from small coastal ports to larger ports for mass shipment overseas on larger Freighters. They have limited range and facilities but large cargo space and hoist. Plan was to convert ~ 50 coasters each with a pair of light flak guns and to mount one 6" gun on each of twenty heavier coasters , while three 3" gun were to be mounted on each of 27 smaller coasters.

These boats had sand added to ballasts to increase stability and provide limited below water protection . In addition concrete was added to the wheelhouse and each gun mount had thin armored shield . This provided small arms resistance and splinter protection all round. In addition each ship was degaussed against magnetic mines.

Historically only 5 of 20 heavy 6" gun coasters were converted and 27 lighter 3" gun coasters were converted. But another 200 guns/howitzers were made available for usage on such improvised gun ships. Although the ships were quite small they had high free boards allowing operations in 'sea state 6' or 3-4m waves and 40-50kph winds. [P Schenk "Invasion of England 1940" , pp 46-48].

Pioniersturmboot 39
It was planned to convert and deploy hundreds of fishing boats to land assault troops with each wave. The plan was to mount them on ramps on either side of the hundreds of fishing boats, Trawlers ,Coasters and Minesweepers. These boats were able to haul a 50-75 troops plus light arms and deploy them ashore @ 25kph [15knts] through a pair of assault boats launched and deposit and recovered through ramps mounted on the side of the boat. It was shown through trial and error that these fishing boats could launch the assault boats quite well traveling at ½ speed [IE 5-6 knts]. The assault boats were the Pioniersturmboot 39 , of which about 500 out of planned 1500 had been delivered in time for Sealion. By December about 800 had been assembled for this task, when the effort was halted.

[P Schenk "Invasion of England 1940" , pp 48-58].

Each invasion group had a leader boat 10knts speed, plus two tugs to tow one powered and one unpowered barge. At a prearranged point the barges would be detached and the powered barge would tow the un powered barge into shore. Most barges had a light flak gun mounted amid ship , although hundreds mounted either 3" howitzers or Pak guns. While useless at hitting ships [3 near misses on 100 test shots @ 600-1000m range], they were thought to be very important in contributing fire support to landing troops, while vulnerable on the beaches.

While the build up was rushed massive and impressive one is left with the impression that given enough time the cross channel invasion would certainly have worked. There is clear evidence that the Germans had been experimenting with amphibious assaults since 1925 and plans for such an invasion of UK had been in the works since 1938 ...but Hitler would hear nothing of these developments due to his believe in England as an ally.

Finally the plan didn't envisage the need to attain air supremacy over England prior to any invasion as is commonly reported, instead all that was required was air superiority over the channel, which was achieved in September 1940. [P Schenk "Invasion of England 1940" , pp 246].At the end of the day the decision to go or not to go rested with Hitler himself and he could not throw his belief that the Brits would cave with draw from the war and allow him free hand in the east. He played each service branch off against each other since it served his purpose to put the pressure on the UK to fold. Schenk notes the following in conclusion pp 357-358.

"If conditions had been right , the German air superiority over southern England should have sufficed for a German landing operation. However, Germany had still hoped to bomb Britain into submission,".....

"In the autumn of 1940 the navy had the chance to end the conflict with Britain with one lightning combined arms operation. While it was able to amass a hugh transport fleet in a Herculean effort , the navy considered it impossible to protect. Ansel contradicts this notion, regarding it conceivable that a British attack on the fleet could have been thwarted given sufficient measures on the part of the navy and Luftwaffe. if all the factors are taken into consideration-Luftwaffe attacks on the Royal navy, mine barriers , coastal artillery and the deployment of the German navy in its entirety- then Ansel could be right. Sealion was cancelled primarily for political and not military reasons".

8) Kris

 

[DerAdlerIstGelandet]

Interesting info there, thanks.

 

[Civettone]

Ok then, some more...
From Crete to Sealion

In the Crete operation the 5th German Mountain division was to be transported by small fishing boats/barges from Greece ~ 300km to the Island of Crete in 3 days. Just before they reached the shores of Crete RN squadrons intercepted them, but failed to wipe them out.

In the initial clash a small convoy of 5 merchant ships transporting 600 troops apiece escorted by 3 Italian destroyers, each with ½ dozen 4.7" guns. This was pursued by a flotilla of 4 x RN destroyers each with Radar and 8 x 4.7" guns. When they finally spotted the Convoy on Radar, they closed with and sank the entire Italian/German convoy plus escorts with minimal loss["The Naval War in the Mediterranean 1940-1943" Jack Greene Alessandro Massignani; pp162-164].

Clearly this is an example of the risk that merchant convoys would take transporting troops, however it should be noted that in this case the RN had advanced warning the time of the troop convoy sailing and the route they intended to take allowing for the idealize definitive interception attack to be made under the best conditions [At night with Radar against an enemy with no radar and no warning]. Few warships had radar in 1940 and by 1941 the British intelligence situation had turned around with the Ultra decrypts being intercepted, meaning the RN had what they would lack in 1940.

In Crete on the 21st of May 1941 two RN groups would intercept these amphibious groups at Cape Spada and near Retimo on the next day. RN Group C had 5 x Light Cruisers and 3 Destroyers , while Group D had 3 Light Cruisers and 4 Destroyers. These groups would arrange an over night interception of the amphibious fleets heading towards Crete, while 2 RN battleships would patrol the eastern approaches incase any Italian capital ships showed up.

Over night the RN Group C was able to sneak to about 2km range and ambushed the Cape Spada convoy of 20 small 'Caique' boats carrying about 2300 German troops and escorted by a single Italian Torpedo Boat. While the lone Italian put up a fight, hitting one of the destroyers, it was sunk along with 10 of the 'Caique' boats. Prompt actions by the surviving 'Caique' boats, meant only 300 of the 2300 troops were lost. It was in this action that some of the Greek Caique boats were reportedly swamped by passing warships ["Hitler's Mountain Troops" James Lucas, pp 74] , but as can be seen , it was far from a fool proof method of attacking convoys, since it took a sweep of 7 Destroyers and Cruisers to just sink 10 'Caique' boats and an escort , while the other 10 'Caique' got away.

The next morning RN Group D intercepting a squadron of 30 x 'Caique' boats escorted by another Italian Torpedo Boat near the Retimo. This time the Italian Torpedo boat aggressively put down a smoke screen to cover the 'Caique' squadron and charged the approaching RN group, that was also under heavy air attack by Luftwaffe bombers. This combined action drove off the British squadron allowing the second convoy of mountain troops to escape with the loss of only one 'Caique', but the amphibious Squadron was forced to return to Greece. Later another convoy would arrive with troops at Crete. Overall it should be noted that over the 6 days, only one coordinated attack by the RN was attempted in which a total of RN 8 cruisers and 7 destroyers assaulted a group of up to 50 x 'Caique' boats, ½ dozen warships and a dozen troops ships, sinking ¼ of these boats with 10% RN loses and driving off ¾ of the invading Axis ships/boats.


This is an interesting comparison with "Operation Sealowe", since these German amphibious squadrons planned to deploy about 50-150 x barges and ferries at a time that on paper could only be escorted by a couple of torpedo boats. In practice however they had 433 Auxiliary patrol craft and planned draw for escorted by up to 2 dozen Minesweepers/Vorpostenboote gun boats each armed with 1-2 x 88mm/4" guns, with considerable Luftwaffe fighter and bomber coverage.

If the Crete action is any indication the Germans will be able to fend for themselves. Problem is that each such RN sweep can only be conducted once every few days when the threat is every day. In desperation it could be done every day but with diminishing returns. What's more with two dozen German barge squadrons on the go at all times, at most ¼ would be in the water during any given RN sweep. Of those ½ dozen invasion groups hit by sweeps in any given day, maybe 3-4 would be driven off while the last couple get through suggesting , overall almost 90% of these groups should get through… an observation that Churchill himself also made.

Worse still if the RN sweeps ignore these squadron escorts and swamp the barges, they risk being bombarded with hundreds of shells per minute, to say nothing of Luftwaffe intervention. At short range such shells will seriously damage any destroyers they hit possibly preventing them from returning for days or weeks. In Crete ½ the RN attacking ships charged the Axis escorts while the rest chased down the barges. The KM would have enough escorts to meet each of these threats to the squadron. In such cases these KM escorts will no doubt suffer badly in such exchanges, but the inability of the attacking RN warships at Crete to ensure the destruction of only a couple of escorts brings into question the success of such RN tactics, especially in the 'larger picture'. There would just be too many Axis invasion groups and too few RN sweeps doing too little damage to dramatically alter the out come.


While all the above mentioned invasion forces and counter invasion forces clash at sea , air battles would rage overhead along the lines of the historical "Battle of Britain". The direct impact of airpower on naval action however may not be as significant as some imagine. Early in the war anti shipping air attacks were not very effective at all. During the historic evacuation from Dunkirk, the Luftwaffe threw 300 bombers at the British fleet for about a week.

In that case the 300 bombers [He-111/Ju-88/Ju-87] sunk/damaged 45 warships 66 transport ships and 80-100 smaller boats sunk. Any ship that is heavily damaged would take weeks or months to repair and bring back to service, so in that context of any invasion of the UK , they are out of the battle and would only exist as enhancements to the existing Harbor defenses.

In terms of air attacks, both sides expected the Luftwaffe to maintain air superiority over the immediate channel crossing areas, however port invasions groups around the country may not be protected at all from the air, other than indigenous flak defenses of the escort ships involved.

The RAF had 660 bombers 'available' in mid 1940 with some heavier 'Whitley' Bombers carrying up to 7000 Lbs loads [compared to 4000lb maximum for the German bombers]. This suggests the RAF should more than double the Luftwaffe kill rates [adjusting relative delivery to about 2.3 times the German delivery rate]. However the RAF bombers were level bombers with at best a CEP of 200-400m compared to the German bombers at Dunkirk many of which were Stuka Dive bombers with a CEP of 30m.

It maybe that the RAF would be no more effective at sinking the German fleet , as the Luftwaffe was at sinking the Dunkirk rescue fleet. Worse still while the RAF did contest the German bomber attacks at Dunkirk, it was little more than 300 sorties a day and about 30-40 fighters at any time. By comparison the Luftwaffe could draw on up to 1300 Me-109s and 1500 Bombers, of which only about ½ could reach over southern England. That means roughly speaking the other half should be available to cover the channel . Thats >600 x Me-109s fly about 1 sortie a day in reserve to counter RAF attacks over the channel. In other words while the Luftwaffe outnumbered the RAF over the sky's of Dunkirk up to 6:1 , the RAF would at best match the Luftwaffe 1:1 over the English Channel during 'Sealowe'. In that situation RAF Bomber Command are likely to suffer severe attrition to the Me-109 , which after all where the best interceptors of their day.

If we are extremely generous to the RAF it could translate into them sinking roughly ~ 250 German ships/boats each week [Luftwaffe success based on "Hitler's Blitzkrieg Campaign", pp 258]during the amphibious assault phase in the Kent region, that's about 6% of the invasion force per week. Per day that's ~36 x warships /merchants / trawlers and smaller patrol boats and towed barges. At that rate of destruction, it would statistically take > 16 weeks of uninterrupted RAF bomber attacks to completely destroy/sink the entire amphibious fleet, and 8 weeks to reach the 50% German imposed cut off point. Mean while, during the same time period, the ~600 Luftwaffe bombers should be able to sink/damage 90 ships/boats per week with the same level of uninterrupted bombing attacks.

So if we intergrate these two experiences we get 250+ 100 German boats/barges/warships lost each week against 90 +12 RN warships. Roughly 3.5 :1 kill ratio. The germans can count on upto 3400 boats barges and warships suggesting 50% level would be reached after 5 weeks of contineous success, however the RN anti invasion fleet can only count on maximum 90 Cruisers and Destroyers backed up by 40 minesweepers and maybe 300-400 armed trawlers ....maybe 450-500 warships . RN could reach the 50% kill rate after 5 weeks , but would cost their entire anti invasion fleet. But that presupposes that German ground troop action doesn't significantly alter the battle calculus, which it should.

 

[Civettone]

And because I couldn't all fit it in the previous one, here's the rest.

(...) the primary strategy for usage of German capital ships was to draw off the Home fleet and ensure it didn't meddle in the channel. Churchill was aidding the Germans here by insisting that no battleships would enter the channel unless German battleships went their first. Further the RN Admiralty feared mostly the German capital ships savaging the convoys and always held the battlefleet and cruiser squadrons on standby for precisely that mission.

A combination of surge of Uboat fleets and Capital ships into the North Atlantic convoys would have stripped off "Home fleet" and if Forbes had his way, 1/3 of the "Anti invasion fleet"....leaving a mere 60 crusiers/destroyers to cover the entire British coastal defenses. They would be aided by 50 minesweepers and several hundred armed trawlers.... but with 3000km front to cover, that left at most 50-60% to cover the channel.

Despite what some will tell you, atleast 1/3 of that force would be down for long term overhaul maintenance and the rest would have to rotate deployments meaning at most 1/3 would be available. Given that the Germans had more such auxiliary warships to concentrate on the south coast suggests problems for the RN. Running warships continuously for periods of more than weeks exhausts the force involved, so its important for the Germans to trigger the RN surge weeks ahead of any cross channel operation.

The RN crusier/destroyer elements could remain on standby for alert , but again would be unlikely to sink more than one enemy barge/boat per sortie. The danger there is timely Luftwaffe port bombing and minning ops could sufficently delay such sorites to allow KM surges across the channel or Uboat ambush to be set up. No where in the Sealowe plans is there mention of the role of the German Torpedoboot/Zestroyers and Light cruiser mission. All the escort missions for the invasion fleet are Minesweepers/Sperrbrecher/Vorpostenboot/Rboot . I suspect the warships could be used to intercept such RN crusier/Destroyer sweeps before they reach the channel/crossing area.

Historically such clashes between RN/KM flottilas usually ended up even with both fleets heading for home at the conclusion of the clash. Mind you at night it was most of the battle just to find the enemy warships, since few if any warships had radars and most of those were with the "Home Fleet". If the german capital ships could decoy the homefleet away for several weeks ahead of any cross channel invasion , they would have served their purpose.





And about the Sandhurts wargame:

The 1970s wargame is plain silly and unfortunately typical of many 1970s games. With out any explaination 50% of the German invasion fleet is wiped out in one day!!! Given that the 1st day invasion fleet counted 100 merchants and 1550 barges plus 400 tugs similar number of coasters to say nothing of 180 minesweepers/VBoot/RBoot, that would require sinking atleast 750 barges 50 merchants and 200 coasters. No doubt they would have to do this after they had destroyed a sizable section of the escorts and tugs etc. No one seems to be able to point to any realistic historical event that can be used as a yard stick with which to measure the validity of such claims. Crete proves the RN would have to be several times its historical size to achieve even a fraction of this.

Again given that in the entire war period the combined commonwealth/American fleets facing the AXIS in Europe, only sank 4200 vessels including merchants listed at 100 tons or more, during the entire 5 years of fighting during the war. We are left to ponder how on earth would the south coast section of the anti invasion fleet [200 trawlers , 1/2 of which would be armed, plus ~60 DD/CL], be able to achieve this in a day. RAF air power was only able to sink/destroy 65 barges/merchants in ~ 900 sortie in the week prior to the 'Planned Sealion' start.The word phantasy comes to mind.

There is no doubt that the German invasion would have taken longer than planned and cost them hugh in loses and had numerous problems ; but 7 sortie were planned with 2-4 days round trip adding up to 2-4 weeks. No invasion ever works exactly as planned and the fog of war plays a key role . What determines the out come is often the adaptablity and leadership of the invading army. The hugh disparity in expected training /expericence levels of the two armies would figure prominatly in this event.

lwd , what I reported was all that was there. However the barges all recieved concrete/steel/wood constructions to adapt the barges to landing mission. The amount of this averaged about 75-100 tons. In one exercise a merchant was unloaded on to the beach through 24 barge sortie in 14 hours and averaged about 40 tons per load. Its possible the weights listed were gross weight including cargo....but would concrete weight 1000kg/ cubic meter? I thought is was more like 2500kg per cubic meter?

The plan envisaged 1500 barge trips in the first day followed by 400 per sortie for seven consequtive trips. Atleast 400 barges were to remain on each side to help load and unload merchants to the beach.

As some one who was born and raised in the UK , even as a child the idea that the weather in the channel would make any crossing impossible , seemed absurd. Any who bases his National Security on such a unpredictable weather happening is plain irresponsible.

 

[Civettone]

And finally some other interesting points but this time more related to my 1942 scenario:

The Kriegsmarine personnel rose from 190,000 in 1940, to 404,000 in 1941 and 570,000 in 1942.

and

Air superiority was not a requirement of Sealowe...that was political. Raeder had always said it was doable even up until second week in september provided the Luftwaffe bombarded the RN ports and Coastal RAF feilds prior to launch. Luftwaffe doctrine never ever required airsuperiority prior to attack, as long as they suppress the enemy long enough to gain forced entry that was enough. When Goering Hitler elected to go for London instead of filling Raeders requirement the whole thing became moote and it was obvious Hitler was favoring Goerings terror war instead of invasion. That was his choice.


(...) the primary strategy for usage of German capital ships was to draw off the Home fleet and ensure it didn't meddle in the channel. Churchill was aidding the Germans here by insisting that no battleships would enter the channel unless German battleships went their first. Further the RN Admiralty feared mostly the German capital ships savaging the convoys and always held the battlefleet and cruiser squadrons on standby for precisely that mission.

Kris

 

[syscom3]

If the Crete action is any indication the Germans will be able to fend for themselves. Problem is that each such RN sweep can only be conducted once every few days when the threat is every day. In desperation it could be done every day but with diminishing returns. What's more with two dozen German barge squadrons on the go at all times, at most ¼ would be in the water during any given RN sweep. Of those ½ dozen invasion groups hit by sweeps in any given day, maybe 3-4 would be driven off while the last couple get through suggesting , overall almost 90% of these groups should get through… an observation that Churchill himself also made.

1) Comparing the situation at Crete is like comparing Guadalcanal with Leyte. Totally dissimilar.

2) In a 1942 scenario, the RN could keep its patrol boats in action for as long as supplies were available. plan on 24/7 coverage. In addition, you are not factoring in available USN assetts.

Worse still if the RN sweeps ignore these squadron escorts and swamp the barges, they risk being bombarded with hundreds of shells per minute, to say nothing of Luftwaffe intervention. At short range such shells will seriously damage any destroyers they hit possibly preventing them from returning for days or weeks. In Crete ½ the RN attacking ships charged the Axis escorts while the rest chased down the barges. The KM would have enough escorts to meet each of these threats to the squadron. In such cases these KM escorts will no doubt suffer badly in such exchanges, but the inability of the attacking RN warships at Crete to ensure the destruction of only a couple of escorts brings into question the success of such RN tactics, especially in the 'larger picture'. There would just be too many Axis invasion groups and too few RN sweeps doing too little damage to dramatically alter the out come.

1) Your barges are not exactly the most maneuverable of ships. Theyre either being towed and at the mercy of the elements or even if self propelled, they moving at a very slow pace. Your escorts are primarily small patrol craft, auxiliarries and mine sweepers. None of which had the capability fo putting up much of a coordinated fight.

2) referring to comment #1, your barges are either going to be grouped up close together ready for group destruction, or scattered around the channel from currents and weather, just waiting to be picked off one at a time.

3) And if they are caught at night, then your covering ships wont be able to do much at all.

I think you should pay attention to the IJN and USN nighttime encounters in the Solomons between PT Boats and Japanese landing ships. It was generally a one sided affair.

In terms of air attacks, both sides expected the Luftwaffe to maintain air superiority over the immediate channel crossing areas, however port invasions groups around the country may not be protected at all from the air, other than indigenous flak defenses of the escort ships involved.

The LW didnt have air superiority during inclimate weather, nor at night. Once an invasion is begun, the attackers have to follow through. Even if a landing boat gets through to land, if its sunk or badly damaged on the way back, thats a decrease in the logistics capacity for the army.

The RAF had 660 bombers 'available' in mid 1940 with some heavier 'Whitley' Bombers carrying up to 7000 Lbs loads [compared to 4000lb maximum for the German bombers]. This suggests the RAF should more than double the Luftwaffe kill rates [adjusting relative delivery to about 2.3 times the German delivery rate]. However the RAF bombers were level bombers with at best a CEP of 200-400m compared to the German bombers at Dunkirk many of which were Stuka Dive bombers with a CEP of 30m.

And a few hundred bombers at 15,000 feet over a port area will saturate the heck out of it and destroy or damage the naval assetts. A single heavy bomber dropping 7000 lbs of bombs on a barge assembly area will have far more impact than a Stuka with a 1000 pound bomb rying to hit a warship.

It maybe that the RAF would be no more effective at sinking the German fleet , as the Luftwaffe was at sinking the Dunkirk rescue fleet. Worse still while the RAF did contest the German bomber attacks at Dunkirk, it was little more than 300 sorties a day and about 30-40 fighters at any time. By comparison the Luftwaffe could draw on up to 1300 Me-109s and 1500 Bombers, of which only about ½ could reach over southern England. That means roughly speaking the other half should be available to cover the channel . Thats >600 x Me-109s fly about 1 sortie a day in reserve to counter RAF attacks over the channel. In other words while the Luftwaffe outnumbered the RAF over the sky's of Dunkirk up to 6:1 , the RAF would at best match the Luftwaffe 1:1 over the English Channel during 'Sealowe'. In that situation RAF Bomber Command are likely to suffer severe attrition to the Me-109 , which after all where the best interceptors of their day.

Again, why are you comparing the situation in spring 1940 with the probable situation 2 years later. The Brits in 1942 not only have plenty of first class aircraft, but lots of trained aircrews. And thats not even counting the USAAF and USN air assetts that could be brought into the fight.

Now what are your german fighters going to do when Spitfires are on their tails? Ignore them and go for the bombers? Thats a recipie for a short lifespan.

If we are extremely generous to the RAF it could translate into them sinking roughly ~ 250 German ships/boats each week [Luftwaffe success based on "Hitler's Blitzkrieg Campaign", pp 258]during the amphibious assault phase in the Kent region, that's about 6% of the invasion force per week. Per day that's ~36 x warships /merchants / trawlers and smaller patrol boats and towed barges. At that rate of destruction, it would statistically take > 16 weeks of uninterrupted RAF bomber attacks to completely destroy/sink the entire amphibious fleet, and 8 weeks to reach the 50% German imposed cut off point. Mean while, during the same time period, the ~600 Luftwaffe bombers should be able to sink/damage 90 ships/boats per week with the same level of uninterrupted bombing attacks.

You dont understand that for the Brits to win, all they have to do is disrupt the invasion timing so the germans arrive piecemeal or without supplies, at a level that keeps them incapable of offensive action. This isnt hard to do considering there wont be any ports available for offloading heavy material, there will be little if any support during the night or inclimate weather.

Any amphib operation is a difficult undertaking even under the best of circumstances. And an amphib invasion of Britain with very poor logistics, few purpose built amphib craft, and no guarentee of heavy firesupport at the beaches or air superiority over the channel, means your invasion will fail, even before it has started.

 

[Soundbreaker Welch?]

No I just truely believe it would have failed. The logistical problem was too great for the Germans. Had it failed the German army would have been devistated and then the war would have been over quite soon.

Too bad the Fuhrer wasn't more stupid. But then all the later war birds of WWII would likely never have come into existence. (Horrendous reason to be sad, I suppose.) Unless Japan still attacked the United States. They might have not cared if Hitler had lost already.

 

[Udet]

Civettone, just an idea humbly submitted for your consideration:

Some guys here, even when discussing in the "what if" mode, have what they believe is the soundest of the opinions regarding the outcome of the war.

They seem to have no problem with Poland, Belgium, Netherlands, Norway and France...afterwards their mindsets indicate "no matter what" Germany would have lost the war. That simple: it is the "no matter what" operational mode.

The fact Germany lost the war in an overwhelming manner, gives them that certain type of self-reliance to believe they can either easily counter or ridicule any argument that might indicate things could have occurred in a different manner -that would have favoured Germany of course-.

I knew some of the information you posted here; it´s because of that and several other factors that i believe that if Hitler had indeed seriously thought of occupying England, it could have been more than attained.

Finally, if land based Japanese planes promptly sent both HMS Prince of Wales and HMS Repulse to the bottom, i find the assumption German bombers could not have made a similar work with RN large vessels trying to destroy an alleged German invasion force crossing the channel weird to say the least. I assume syscom will have the proper response to suggest the lack of validity of this assertion, or "no matter what".

Cheers!

 

[syscom3]

the primary strategy for usage of German capital ships was to draw off the Home fleet and ensure it didn't meddle in the channel. Churchill was aidding the Germans here by insisting that no battleships would enter the channel unless German battleships went their first. Further the RN Admiralty feared mostly the German capital ships savaging the convoys and always held the battlefleet and cruiser squadrons on standby for precisely that mission.

So in 1942, the KM was not going to see action in the channel? That means your invasion forces wont have heavy firesupport at the beaches. Thats a plus for the Allies. A few well protected bunker and pill boxes would have a field day taking shots at the barges. In 1942, the USN was also in action, so add those forces into the equation. Keep them at the ready to go after the German raiders, allowing the RN to release a few more capital ships.

A combination of surge of Uboat fleets and Capital ships into the North Atlantic convoys would have stripped off "Home fleet" and if Forbes had his way, 1/3 of the "Anti invasion fleet"....leaving a mere 60 crusiers/destroyers to cover the entire British coastal defenses. They would be aided by 50 minesweepers and several hundred armed trawlers.... but with 3000km front to cover, that left at most 50-60% to cover the channel.

OK, the RN and uSN go for the KM raiders. In the meantime, intell will be developed to show the invasion fleet beginning to assemble and sortie. No problem redeploying the RN ships as the invasion details are narrowed down.

Despite what some will tell you, atleast 1/3 of that force would be down for long term overhaul maintenance and the rest would have to rotate deployments meaning at most 1/3 would be available. Given that the Germans had more such auxiliary warships to concentrate on the south coast suggests problems for the RN. Running warships continuously for periods of more than weeks exhausts the force involved, so its important for the Germans to trigger the RN surge weeks ahead of any cross channel operation.

What makes you think the RN will be in constant non stop motion for the several weeks before the anticiapted invasion. Plenty of time to keep them maintained and in fighting trim. Theyre stationed at some of the finest naval installations in the world. Where do you come up with a figure of "1/3"? If I knew an invasion was going to take place when my country's life was ata stake, I would have all ships ready to fight and kept close enought to bring to the fight when required. And stop putting so much faith on the capacity of your auxilliaries to fight in a major conflict. Theyre small and just what their name says..."auxiliaries". They are not warships nor transports.

The RN crusier/destroyer elements could remain on standby for alert , but again would be unlikely to sink more than one enemy barge/boat per sortie. The danger there is timely Luftwaffe port bombing and minning ops could sufficently delay such sorites to allow KM surges across the channel or Uboat ambush to be set up. No where in the Sealowe plans is there mention of the role of the German Torpedoboot/Zestroyers and Light cruiser mission. All the escort missions for the invasion fleet are Minesweepers/Sperrbrecher/Vorpostenboot/Rboot . I suspect the warships could be used to intercept such RN crusier/Destroyer sweeps before they reach the channel/crossing area.

Only one barge per sortie?
A surge across the channel at 5 - 7 knots?
RN subs not sitting in ambush?
RN mining not causing problems for the KM?
RAF/RN hitting the invasion barges at nighttime?

Historically such clashes between RN/KM flottilas usually ended up even with both fleets heading for home at the conclusion of the clash. Mind you at night it was most of the battle just to find the enemy warships, since few if any warships had radars and most of those were with the "Home Fleet". If the german capital ships could decoy the homefleet away for several weeks ahead of any cross channel invasion , they would have served their purpose.

This time its for keeps. Not a small island in the Med, but the home islands. The RN will fight with tenacity and resolve, simply because failure would be a disaster. And go ahead with your KM raiders sortieing into the Atlantic. Just means the BA/RAF and RN will have an easier time with the unprotected invasion craft.

And about the Sandhurts wargame:
The 1970s wargame is plain silly and unfortunately typical of many 1970s games. With out any explaination 50% of the German invasion fleet is wiped out in one day!!! Given that the 1st day invasion fleet counted 100 merchants and 1550 barges plus 400 tugs similar number of coasters to say nothing of 180 minesweepers/VBoot/RBoot, that would require sinking atleast 750 barges 50 merchants and 200 coasters. No doubt they would have to do this after they had destroyed a sizable section of the escorts and tugs etc. No one seems to be able to point to any realistic historical event that can be used as a yard stick with which to measure the validity of such claims. Crete proves the RN would have to be several times its historical size to achieve even a fraction of this.

You dont need to sink an amphib vessel in order to destroy it. All it takes is enough damage so it cant perform its role, and then its useless.... as good as destroyed. Think about the impication of needing tugs to bring in your barges. Tugs are not warships and can be easily damaged. If its not capable of towing its barge(s), then that barge is useless.

Again given that in the entire war period the combined commonwealth/American fleets facing the AXIS in Europe, only sank 4200 vessels including merchants listed at 100 tons or more, during the entire 5 years of fighting during the war. We are left to ponder how on earth would the south coast section of the anti invasion fleet [200 trawlers , 1/2 of which would be armed, plus ~60 DD/CL], be able to achieve this in a day. RAF air power was only able to sink/destroy 65 barges/merchants in ~ 900 sortie in the week prior to the 'Planned Sealion' start.The word phantasy comes to mind.

Comparing apples to oranges. The KM (except u-boats) was not a primary factor in the war. After 1944, there really want any KM surface ships to sink.
maybe you should compare this to some of the battles in the Pacific where there were hundreds of ships clustered in a small area.

There is no doubt that the German invasion would have taken longer than planned and cost them hugh in loses and had numerous problems ; but 7 sortie were planned with 2-4 days round trip adding up to 2-4 weeks. No invasion ever works exactly as planned and the fog of war plays a key role . What determines the out come is often the adaptablity and leadership of the invading army. The hugh disparity in expected training /expericence levels of the two armies would figure prominatly in this event.

Also add logistics. The Brits were far better prepared at all levels in 1942 as in 1940. The question is whether the KM could transport enough troops, follow up forces and THEN SUPPLY THEM faster than the brits could stop them.

what I reported was all that was there. However the barges all recieved concrete/steel/wood constructions to adapt the barges to landing mission. The amount of this averaged about 75-100 tons. In one exercise a merchant was unloaded on to the beach through 24 barge sortie in 14 hours and averaged about 40 tons per load. Its possible the weights listed were gross weight including cargo....but would concrete weight 1000kg/ cubic meter? I thought is was more like 2500kg per cubic meter?

And if they are combat loaded, then the payload is even less. And none of that unlading can take place under inclimate sea states.

As some one who was born and raised in the UK , even as a child the idea that the weather in the channel would make any crossing impossible , seemed absurd. Any who bases his National Security on such a unpredictable weather happening is plain irresponsible.[/i]

Thats why the allies in 1944 planned their logistics on resupply under every type of weather, and had the ships (LST's and LCI's) that could do this.

 

[Civettone]

Eum Syscom ... you do understand that these are not my words, but those of Paul Lakowski, right? Most of it is about Sealion 1940 and has nothing to do with my Sealion '42 scenario. I posted this because Adler also found it interesting, so I thought "why not post some more?".

If you insist, I will go deeper into this but I just want to be sure you're understand the reason why these posts are in italic and why they are much more eloquently written than mine!

Kris

 

[daishi12]

Hi Kris,

Could I just recap on some of the things which you have talked about in previous posts?


You prepose that as a precondition for the invasion of Britain that from early 1942 to Sept 1942 Germany has total control over Russia and there is no significant miltary action in Russia, this in turn frees up resources to plan, develope and build a large number of landing barges and other neccessary equipment. Surely if Russia has been pacified then the Werhmacht would have taken losses to achieve this, also, troops would need to be left in Russia as garrison troops.

You have mentioned that 150 divisions would be available, but I would contend that a fairer figure would be derived as follows :- If there were minimal losses you would still be talking at about 10-15 divisions either destroyed or not combat ready. Given the size of Russia, the amount of garrison troops would need to be approximately 65 divisions. This leaves approx 65 divisions, of whom probably 75% would not be up to full combat readiness. I make the figures to be about 15 divisions who would be fully combat ready.

You have stated that to land heavy equipment in the captured ports the Werhmacht would use the field pioneers. It is my understanding that the field pioneers usually consisted of penal battalions who cannot be considered to be the most reliable of troops.

With regard to wind conditions and specifically the wind state, a Beaufort scale of 4 - 5 is classed as a moderate to fresh breeze with waves up to 1.2m.

In the channel in September the average is 1 in 4 days have rain and fresh breeze would be exceeded on a fairly regular basis. You have stated that of the available barges approx a quarter suffered damage, some with damage to the bow ramp. If the bow ramp is damaged/open on a landing barge there is a good probability that the barge will sink.

You have also stated that the inital attack will take place starting at night to land at dawn in absolute secrecy in order to gain tactical surprise.

How will this happen? If you want the barges to land in the correct area you MUST train the crews, it is not something that an untrained sailor can do without training. You must also load the troops and equipment at the last possible moment. The French resistance would let Bletchley Park know what was going on within at the most an hour of the troops being loaded. The RAF, USAF, RN, USN and everyone else would be on full alert ready to repel borders.

In short I believe that while you do have the right to your own opinion, please try to understand that the invasion of Britain could realisticaly have occured in either 1940 or 1942.