Was Sea Lion possible?

[Vukodav]

So yeah. The Allied landing craft used during D-Day were, on average, about 12 times the size of the Pilabos 39. That makes my factor of 10 pretty-much bang on doesn’t it?

No, it does not, because you made an assumption that Germany would need the same amount of troops and resources for the invasion of UK as the Allied invasion of Europe. Germany did not need a force that large nor did it need to sail over the ocean - that is why I did not assume that the landing vessels were of the same size, while you did. Also, you used the lifting power of a barge to determine how many landing crafts you would need - and that is how you got yourself the 10 factor. That is some bad math. That barge, if you only look at a lifting power, would be able to load 10 M4 Shermans or 15 Panzer III. Good luck fitting them on. If you use lifting power in order to do the calculations, let me do some real math for you.

Lifting power of the barges was between 360 and 620 tones. Average - 490. But as that is a bad number to use, we do not know how many of what type of barges were there, let us assume that all were the smallest ones with 360 tones capacity. 2400 were gathered. That gives you 860.000 tones of cargo lifted in a single run, if you use lifting capacity as variable here, as you did.

Now, let us compare it to the D-Day. Almost a month after the invasion, 850.000 men, 570.000 tons of supply. Now, men and supply alone would add up to (let us say that your average soldier is 100kg with his gear), it gives you 655.000 tones being required to be lifted over a month of a D-Day invasion.

So, if you use the lifting power to determine how many landing craft you would need, as you did and got to 40.000 and the 10 factor, it would seem that a single run of German barges would transport more in the terms of man and supply than a month's worth of transport for a D-Day. Around 25% more. Hell, let us even calculate in the vehicles, again over a month time period. With 148.000 vehicles, 10 tones average (tanks were 30, but most of the vehicles were half tracks, trucks, jeeps that were way below 30 tones, so 10 ton average is fine), you get 1.480.000 in vehicles, 570.000 in supply, 85.000 in men, to the total of 2.136.000 for a month of the D-Day. The amount barges, if you use the lifting power for the calculations, would transport in 3 runs. If we take that all of the barges are the smallest ones.

That is why you do not use the lifting power for your calculations but use the actual number of soldiers, vehicles and supplies that are needed and how much could be fitted onto transports. Otherwise you get some bad math, 10 factor and 40.000 landing craft needed.

 

[hkrommel]

Germany did not need a force that large

Germany planned to use many more divisions.

 

[Midden]

Yes, except that the size and scope of the operations were vastly different, and there would be no need to supply the forces in Stalingrad if they were simply allowed to slowly withdraw before the encirclement happened. Stalingrad was not even the most important part of the offensive. If the 6th Army had been sitting on the Caucus oil fields, then I might have more sympathy.

Everything is easy with hindsight, I think Germany thought they were winning at Stalingrad..... wearing the Red Army out and hoped it was on it's last legs... it wasn't until 6th Army was surrounded that reality dawned, and serious talk of retreat and break out, or staying and supplying the pocket. I think the size and scale of operation Uranus really shocked and surprised the Germans that Red Army had both the strength and the capability to launch it.

Sorry to deviate from Sealions.

 

[hkrommel]

Everything is easy with hindsight, I think Germany thought they were winning at Stalingrad..... wearing the Red Army out and hoped it was on it's last legs... it wasn't until 6th Army was surrounded that reality dawned, and serious talk of retreat and break out, or staying and supplying the pocket. I think the size and scale of operation Uranus really shocked and surprised the Germans that Red Army had the capability.

Sorry to deviate from Sealions.

Quick OT detour then back to Sealion

The Germans were perfectly aware of Soviet capabilities in the area, it's just that officers like Halder, for example were dismissed or silenced in other ways when they noted the vulnerability of the 6th Army.

Anyways, I'm really just waiting to hear any decent explanation as to how these barges (which will be sitting in the channel for over a day) will survive any attack? I mean even strafing near them will sink them, as too many people moving to one side capsized one of the barges during an exercise. You don't even need to hit the barge. It's absurd, they would be better off swimming or all getting on board Scharnhorst, Gneisenau, and Prinz Eugen and beaching themselves on the shore. They could even use the guns as artillery support

 

[Earl Uhtred]

From the looks of it, the war has been decided in 1939 already, so all that fighting already had a final destination.

Hitler's only hope of victory was a political settlement in the West from a position of strength some time before the attack on the Soviet Union, something HoI (or any other PC game I'm aware of) has never modelled adequately. Then there is the question whether Stalin was preparing an attack of his own, and how that might have played out.

I think it's generally accepted any realistic hope of a favourable outcome for Germany passed in 1941.

 

[AchedTeacher]

Um, no.

 

[Vukodav]

Germany planned to use many more divisions.

Germany did not plan a thing, the whole operation was a bluff. And even in it, the force was to consist of 25 division at its height during the battle, while the Western Front from 1944 had more than 5 million soldiers.

 

[hkrommel]

Germany did not plan a thing, the whole operation was a bluff. And even in it, the force was to consist of 25 division at its height during the battle, while the Western Front from 1944 had more than 5 million soldiers.

You aren't making any sense. The Allies didn't land 5 million soldiers. For the Germans to not be crushed at the beachheads they would need to land more soldiers than the Allies did since they would be facing heavier initial resistance (because they couldn't pull off the kind of intelligence coups the allies did) while they would have greatly weakened capabilities (very little heavy equipment).

Hitler's only hope of victory was a political settlement in the West from a position of strength some time before the attack on the Soviet Union, something HoI (or any other PC game I'm aware of) has never modelled adequately. Then there is the question whether Stalin was preparing an attack of his own, and how that might have played out.

I think it's generally accepted any realistic hope of a favourable outcome for Germany passed in 1941.

After December 7, 1941 the Axis could not win decisively (as in, dictate terms). Even after that point if the United States had not gotten involved (which was going to happen, Pearl Harbor or not) the Germans could have conceivably bombed the UK into submission given enough time and a speedy resolution of the Eastern Front.

After Operation Torch, Stalingrad, and Midway the Axis could not win the war even in a negotiated settlement. Up to this point it would conceivably be possible, if not probable given their position of strength in the Soviet Union, western Europe, and the Pacific.

After Husky and the landings in Italy, Kursk, and the American pushback in the Pacific (Guadalcanal and the like), the Axis was facing defeat, though conditional surrender may have been on the table.

Overlord just put the nail in the Axis coffin of having any chance of a negotiated settlement.

 

[Vukodav]

You aren't making any sense. The Allies didn't land 5 million soldiers. For the Germans to not be crushed at the beachheads they would need to land more soldiers than the Allies did since they would be facing heavier initial resistance (because they couldn't pull off the kind of intelligence coups the allies did) while they would have greatly weakened capabilities (very little heavy equipment).

Again, not true. Initial landing for German bluff were 88.000 troops, D-Day had 170.000 troops invading. And both Allies and Germany had heavy weapons come in AFTER the initial invasion (so you cannot say that Germany would need more than a D-Day invasion because the D-Day invasion did not have it as well). The very notion that invading of the UK in 1940 (and it is well known in what shape and form the UK land forces were at the time) takes MORE men than invading whole Europe where 1.500.000 Germans are dug in... I do not even know what to say.

And about the surrender - no. First, Axis would not stand for it, it was a fight to the death. Second, Allies would not stand for it. Churchill first then Roosevelt second said that there was not going to be ANY negotiations with Germany as early as 1942-43.

 

[hkrommel]

Again, not true. Initial landing for German bluff were 88.000 troops, D-Day had 170.000 troops invading. And both Allies and Germany had heavy weapons come in AFTER the initial invasion (so you cannot say that Germany would need more than a D-Day invasion because the D-Day invasion did not have it as well). The very notion that invading of the UK in 1940 (and it is well known in what shape and form the UK land forces were at the time) takes MORE men than invading whole Europe where 1.500.000 Germans are dug in... I do not even know what to say.

And about the surrender - no. First, Axis would not stand for it, it was a fight to the death. Second, Allies would not stand for it. Churchill first then Roosevelt second said that there was not going to be ANY negotiations with Germany as early as 1942-43.

Are you including airborne divisions? We're talking about sea transport. Even if you include the Ranger battalion at Point du Hoc the Germans were planning to land more.

Also, the Allies landed heavy weapons immediately. I met a guy once who was a crewman in a Sherman that landed on Omaha in the first wave. The rest of his platoon was knocked out but they landed more tanks.

The very notion that invading of the UK in 1940 (and it is well known in what shape and form the UK land forces were at the time) takes MORE men than invading whole Europe where 1.500.000 Germans are dug in... I do not even know what to say.

Neither do I. Even cursory wikipedia research shows that you're wrong. The only notable defense was at Omaha Beach, the rest of the initial resistance faced was made up of maybe second-line troops.

And about the surrender - no. First, Axis would not stand for it, it was a fight to the death. Second, Allies would not stand for it. Churchill first then Roosevelt second said that there was not going to be ANY negotiations with Germany as early as 1942-43.

I'm not saying it was going to happen, I'm saying it was possible if cooler heads prevailed. The Axis failed to capitalize on its early successes, which it could have easily done with a negotiated settlement.

Also, rhetoric and action are two very different things. Do you really think the Allies wouldn't jump at the chance for Axis surrender, even as late as 1943? They could avoid much of the fighting in Italy, all of Overlord and subsequent operations, and they could secure Europe from Soviet control. Churchill may be reluctant but Roosevelt would be much more amenable to such a solution, at least with Germany. Obviously there would be conditions (Hitler stays in power, probably Germany gets the Danzig corridor and holds on to pre-1939 gains). It's certainly a possible outcome, if not the best one for the world.

 

[Uniform764]

And both Allies and Germany had heavy weapons come in AFTER the initial invasion (so you cannot say that Germany would need more than a D-Day invasion because the D-Day invasion did not have it as well)

The allies had specialised amphibious tanks. They also had tank landing craft able to to deploy armour straight onto the beach, armour that was specifically designed to and overcome the German fortifications. Plus the allies had capital ships anchored off shore and 15" naval gunfire on demand is an asset that equals if not surpasses 2.75" howitzer support. They also had complete air supremacy with roving fighter bombers shooting up anything that moved in daylight. The Germans would have none of those things.

The very notion that invading of the UK in 1940 (and it is well known in what shape and form the UK land forces were at the time) takes MORE men than invading whole Europe where 1.500.000 Germans are dug in... I do not even know what to say.

Nobody is suggesting that a succesful Sealion required more men than liberating Europe. However for the purpose of D Day and the aftermath, 1,500,000 Germans were dug in mostly in the wrong place and spread out across France. D Day pitted about 150,000 allied troops, with overwhelming air/sea control against about 50,000 Germans. By the time the Germans could redeploy to face the invasion properly, the allies had established, secure beachheads, thousands of troops ashore and complete impunity to land more men, vehicles and supplies to continue the offensive.

By the end of July there were about 1,300,000 allied troops ashore, facing at best 400,000 Germans. That's over 3:1 in the allies favour. In your hypothetical Sealion the initial 10 (best case scenario) Germans divisions would be facing about 25 British/Commonwealth divisions, including at least two armoured ones. So the attackers are outnumbereds 2.5:1. Without control of the seas and multiple major ports to continue ferrying in additional men, tanks and supplies there is no second wave and that first wave will be systematically destroyed.

 

[Vukodav]

The allies had specialised amphibious tanks. They also had tank landing craft able to to deploy armour straight onto the beach, armour that was specifically designed to and overcome the German fortifications. Plus the allies had capital ships anchored off shore and 15" naval gunfire on demand is an asset that equals if not surpasses 2.75" howitzer support. They also had complete air supremacy with roving fighter bombers shooting up anything that moved in daylight. The Germans would have none of those things.



Nobody is suggesting that a succesful Sealion required more men than liberating Europe. However for the purpose of D Day and the aftermath, 1,500,000 Germans were dug in mostly in the wrong place and spread out across France. D Day pitted about 150,000 allied troops, with overwhelming air/sea control against about 50,000 Germans. By the time the Germans could redeploy to face the invasion properly, the allies had established, secure beachheads, thousands of troops ashore and complete impunity to land more men, vehicles and supplies to continue the offensive.

By the end of July there were about 1,300,000 allied troops ashore, facing at best 400,000 Germans. That's over 3:1 in the allies favour. In your hypothetical Sealion the initial 10 (best case scenario) Germans divisions would be facing about 25 British/Commonwealth divisions, including at least two armoured ones. So the attackers are outnumbereds 2.5:1. Without control of the seas and multiple major ports to continue ferrying in additional men, tanks and supplies there is no second wave and that first wave will be systematically destroyed.

I just love it how, when the D-Day is in question, we take all of the allied force and assume that all of the German force was spread around and weak, while for the Sea Lion, you assume that 25 British division would be concentrated and all that in one place, and that place would be a landing ground.

As I said, no objective argument to be made here what so ever when the Allies are in question. I am done wasting my time on this subject any more.

 

[hkrommel]

As I said, no objective argument to be made here what so ever when the Allies are in question. I am done wasting my time on this subject any more.

lol, says the guy who claimed the Allies didn't land heavy equipment on D-Day when there were tanks in the first wave .

 

[Uniform764]

I just love it how, when the D-Day is in question, we take all of the allied force and assume that all of the German force was spread around and weak, while for the Sea Lion, you assume that 25 British division would be concentrated and all that in one place, and that place would be a landing ground

We know from historical evidence that the Germans expected the attack to come at Calais from their dispositions on D-day itself and from the unbelievably comprehensive false intelligence that the allies leaked to the Germans to reinforce this belief. On the other hand the British could be pretty certain the landings would be somewhere in the South of England, and there was going to be no surprise assault on Anglesey or Barrow. Also France had a significantly larger interior than the Uk, where nowhere is more than 72 miles from the coast. I'm not for a second claiming that all the British troops would be concentrated at the landing ground, but it seems unlikely the armoured divisions would be guarding against an assault from the Irish Sea

Even if we assume the assault comes as a complete surprise while the most of the army is training up in Northumbria, the reason D-Day was successful is that after the initial waves had secured the beachheads the allies had complete impunity to continue landing more men and equipment, so that within a month they had over 1,000,000 ashore. Even if we assume the Germans land completely unopposed and form up quickly in good order, they're still outnumbered 3:1 and there is no constant stream of reinforcements because the Royal Navy exists.

 

[Swinds]

BANG!!!

(sorry, had to)

that hurt

 

[Henry IX]

The Germans launching Sealion is just possible. If the Germans had invested in building small wooden boats (think lifeboats) they could have built a large number of cheap, shallow draft fairly seaworthy vessels. At least enough to transport a couple of divisions. If everything goes in their favour these can be escorted across the channel. The problem is that there is no conceivable scenario that allows the Germans to support or supply the landings.

There is no scenario that results in the destruction of the RN. This makes long term supply of the landing forces impossible.

The Luftwaffe has too many jobs to do: 1. Control the channel. If the RN can sail down it then its all over 2. Ground attack (the landing forces would have no heavy artillery and would rely on the Luftwaffe to act as artillery). 3. Defence of the ports. If the British can bomb the Dover (or whatever port the Germans posses) docks OR the docks from which the supplies are being loaded then its game over. 4. Protect the German ground forces. If the British can add heavy air attacks to the existing issues then the invasion will fail. All of this needs to be done without the benefit of effective radar, for weeks, with even a single failure costing the Germans their landing forces.

Nothing the Germans possess could have landed armoured vehicles in meaningful numbers until they capture a port. Once they have a port they then need to decide what lands in the second wave: tanks - then you need to land large amounts of fuel, further overloading your supply system, artillery - again this will add a huge burden to the supply system or more infantry, in which case you can neither storm fortified positions nor exploit any gains you do manage.

Overall, 0% chance of success.

I suspect that the preparations for Sealion may have been due to a combination of not wanting to piss Hitler off by saying "We can't invade there", arse covering (I tried/we were ready but the Luftwaffe/KM/Heer were not) and inter service rivalry - progress with the plan, knowing it will not work, and hope that some other service takes the blame for failure (as it turns out the Luftwaffe did). It is worth noting that neither the Heer nor the KM actually did much, just gathered together some of the equipment needed and waited for the Luftwaffe to win, which I feel supports this interpretation. Of course, Hitler was probably trying to keep his options open - try to bluff the British into surrender, or if the Luftwaffe wins the Battle of Britain, try to invade.

 

[Earl Uhtred]

I suspect that the preparations for Sealion may have been due to a combination of not wanting to piss Hitler off by saying "We can't invade there", arse covering (I tried/we were ready but the Luftwaffe/KM/Heer were not) and inter service rivalry - progress with the plan, knowing it will not work, and hope that some other service takes the blame for failure (as it turns out the Luftwaffe did). It is worth noting that neither the Heer nor the KM actually did much, just gathered together some of the equipment needed and waited for the Luftwaffe to win, which I feel supports this interpretation. Of course, Hitler was probably trying to keep his options open - try to bluff the British into surrender, or if the Luftwaffe wins the Battle of Britain, try to invade.

That's pretty succint. Sounds like where I work.

 

[Swinds]

That's pretty succint. Sounds like where I work.

Do we work for the same company

 

[Shade205]

If the battle of Britain was won then maybe MAYBE it was possible. People tend to underestimate the power of air cover over control of coastal waters and tend to over estimate the size of the English Channel.

Feel I should add the disclaimer that this is with proper planning from the get go (planning for such an invasion early on and preparing the proper equipment) the situation the Germans were in after France fell and to all of a sudden spring a "hey lets sealion!" Decisions at last minute it was not possible at that point.

 

[Swinds]

Silly question how many people on this tread have actually been across the English channel?

I have and I will choose not to thank the pretty girl that gave me extra bacon and sausage before we left harbor. I found I don't like larger boats in rough seas. It takes a surprising amount of time to cross!! Cannal barge... Channel.... mmmmm

PS it was early October coming back from Germany after an international walk in Boppard.