Questions Regardin the Sea Mammal That Shall Not Be Named

Kevin C. Smith

Questions Regarding the Sea Mammal That Shall Not Be Named

It is with soft and fearful tread I enter...

Not to suggest that the Nazi invasion of Britain could have succeeded. Many posts on this topic have explained so many aspects of the shortfall of German resources to accomplish the task. But, I'm more curious of just how bad the shortfall was? I know-"a whole lot". But if someone has something more concrete. Imagine yourself, if need be, as a staff officer in OKW getting a memo saying, "We want to invade Britain. What will it take to accomplish this? What do we have of what is needed? How much more should we have?" A snapshot, if you will, of the need vs. ability between Dunkirk and Barbarossa.

For example, air superiority/supremacy is needed. At the loss rates of the LW and RAF, how many more planes (of what kind) are needed-right now-to protect the crossing, landings and advance off the beachheads? Haw many ships will be needed to hold back the RN and keep the invasion force and subsequent supply lines open? How many supply ships are needed to keep going to London? How many parachute troops? Transport planes? How much at the ready to launch the invasion, and what kind of production to stay on track?

I know it is a large and multi faceted exercise. I have read many analyses of different parts of the problem from many posts on other threads but not (and-please-direct me to an existing thread that has asked this already if one exists that I missed) "all in one place".

I'm not looking for what Germany could do but, rather, what Germany needed to do in order to be able to succeed...some sort of quantification of what we already know in general. Revisions to the invasion plan are OK but, please, limit yourselves to only what equipment was actually available for use in the time period (e.g., no nukes, V weapons, jets, etc.).

I know this is a big topic and I scarce expect a definitive answer to all of it but any information from anyone's area of expertise would be helpful.
 
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von Adler

von Adler

The big problem for the Germans is transport capacity and how to protect it.

The Luftwaffe probably could establish temporary air superiority over the landing zones. They probably could keep all but a few destroyers out against the landing fleet.

However, with the barge fleet gathered, the Germans were not only hurting their economy (the barges were needed for riverine transport), they also lacked the ability to get reinforcements and above all supplies across the channel.

The barges were completely dependent on calm weather, and a single MTB or destroyer getting through to the barge fleet would not need to shoot the barges up - it could simply speed past and let its wake waves make the barged capsize and sink.

What the Germans do need for a successful Sea Lion:

1. Fighters with longer range so they can stay over Britain longer (to force the RAF to move their air bases further north and have a slightly longer response time).

2. Radar on par with the British - probably in mobile stations that could be quickly moved to France, which was very rare 1940.

3. Many more air transports and their airborne forces not chewed up in the Netherlands (for dropping two airborne divisions AND supplying the troops).

4. A much stronger navy, especially in mining and transport. The Germans need to be able to drop mines to almost shut the English Channel off. They also need to be able to defend those minefields. They need to be able to transport a strong force across the channel and supply it. That will require purpose-built military transports. The Germans did build quite a few nice landing and transport ships, with the first ones arriving 1941 and used in the Baltic and on the rivers of Europe (the Yugoslav navy continued to use a few up to the 1980s).

http://www.german-navy.de/kriegsmarine/ships/landingcrafts/

The problem with all of these requirements is,

A. They don't happen in a vacuum. The western allies and especially Britain will respond in kind.

B. It requires several years of preparations. No-one expected the French to fall in a few weeks, not even the Germans. And no-one expected the British to carry on fighting if they did. Germany did not have a requirement for naval landing capacity 1935-1940.

C. All resources given to any programs along the note above will be taken from somewhere else, which might weaken the German ability in other fields, which might change history up to 1940.
 

lycan

Gain control of the western Mediterranean--specifically the strait of Gibraltar, and have Vichy France send some of its own vessels through. They might have had better landing craft than the barges Germany planned to use, but I'm not sure.
 

Saphroneth

Banned
lycan said:
Gain control of the western Mediterranean--specifically the strait of Gibraltar, and have Vichy France send some of its own vessels through. They might have had better landing craft than the barges Germany planned to use, but I'm not sure.
Click to expand...

That's unlikely to happen. Vichy France was NOT an Axis co-belligerent - the whole point of the Vichy regime was to negotiate peace with Germany. Not to sign on with the Axis. (Allied invasions of Vichy territory took place some years later, and the forcings which changed attitudes on all sides won't take effect overnight.)

Also, the Brits were paranoid about Vichy ships supplementing the Kriegsmarine. Even OTL, they shot up or otherwise strongarmed Vichy warships.
And if you need to get landing craft into a position to support an invasion of Britain, you don't just need control of the western med. You need control of the western med, the eastern Atlantic Ocean and the Channel Approaches - in other words, you need to gain control of the sea away from the Royal Navy, and you need to do it in an area VERY close to their bases... and on the other side of a narrow strait and a long sail from your own.
 

Shaby

The Germans also needed to have a real experience in the whole 'landing on the enemy shore while being shot at' business. They'd need to adopt an approach tad bit more serious than 'oh, let's treat this as we would the really wide river crossing'.

They would need to have at least a few divisions that are trained and experienced in landing operations, maritime personnel that are able to execute a landing in an orderly fashion, specialized equipment to handle 'supplies over the beach'.

They would need to have something at least remotely approaching effective espionage network on the enemy shore, at least able to provide general data on enemy dispositions in close to real time.

In effect, they would need to have most or at least many of the things the Allies had during the Overlord.

Now comes the tricky part.

First of all, the British would have knowledge that the Germans have these things (though probably not of the 'effective espionage network', if it is effective). So they would either try to create countermeasures. If they are uncertain of victory, the British would most likely surrender. Or to put it more plainly - the situation that makes Sealion likely to succeed, also makes it likely unnecessary.
 

Astrodragon

Problem is, even if we give Germany more advantages it still fails.

The Norway campaign didn't help, it basically destroyed the German navy. But without the Norway campaign, the British have additional strength at home (and fewer damaged ships).

Some idea that they might actually have to attack ships from the air might have helped (I mean, the Luftwaffe is going up against the worlds largest fleet, who'd have thought they needed anti-shipping tech...:eek::p). The Luftwaffe had an abysmal record against ships off Dunkirk, in absolutely the most favourable circumstances for them. Closing off the channel... not going to happen.

Radar wouldn't have done much, the Luftwaffe targets were known and easy to find in daylight. Damaging the UK radar system was possible (and done), but extremely difficult to keep offline (as again was found out), and on the occasion it was offline they kept going on visual. Given that landings require decent weather, that would happen again even with a concerted effort.

Any other advantages require a much earlier PoD (which the British will NOT ignore, it was one of their hot buttons), and reduces spend on something else.
 

Saphroneth

Banned
Shaby said:
The Germans also needed to have a real experience in the whole 'landing on the enemy shore while being shot at' business. They'd need to adopt an approach tad bit more serious than 'oh, let's treat this as we would the really wide river crossing'.

They would need to have at least a few divisions that are trained and experienced in landing operations, maritime personnel that are able to execute a landing in an orderly fashion, specialized equipment to handle 'supplies over the beach'.

They would need to have something at least remotely approaching effective espionage network on the enemy shore, at least able to provide general data on enemy dispositions in close to real time.

In effect, they would need to have most or at least many of the things the Allies had during the Overlord.

Now comes the tricky part.

First of all, the British would have knowledge that the Germans have these things (though probably not of the 'effective espionage network', if it is effective). So they would either try to create countermeasures. If they are uncertain of victory, the British would most likely surrender. Or to put it more plainly - the situation that makes Sealion likely to succeed, also makes it likely unnecessary.
Click to expand...
More to the point, all that extra effort is going to take effort away from something else. Opportunity cost, and all that.
More navy? Less tanks.
More Marines? Well, the training for them is going to take a lot of effort and they might cream off the best soldiers from the regular army.
More Paras? Same again.
Everything has an opportunity cost, and given how close run Sicklecut was it might mean they don't win France so fast... in which case, Britain has many more tanks and aircraft, and even if they have to evacuate it's with more heavy equipment and you lose your chance.
 
Julius Vogel

Julius Vogel

I wonder if it would help if the Germans somehow were required to stage several contested amphibious invasions during their Spanish frolic. Whilst perhaps unlikely, it may at least give them a slightly better idea of how these things work/how to do it better.

Probably wouldn't help a lot
 

Ian Hathaway

von Adler said:
The barges were completely dependent on calm weather, and a single MTB or destroyer getting through to the barge fleet would not need to shoot the barges up - it could simply speed past and let its wake waves make the barged capsize and sink.
Click to expand...
This is a Myth …
von Adler said:
2. Radar on par with the British - probably in mobile stations that could be quickly moved to France, which was very rare 1940.
Click to expand...
The Germans did have radar located on the French coast and in some respects it was more advanced than the British.
von Adler said:
3. Many more air transports and their airborne forces not chewed up in the Netherlands (for dropping two airborne divisions AND supplying the troops).
Click to expand...
There were at least 500 Ju52 available with a handful of other transport aircraft and an undisclosed number of gliders.
Astrodragon said:
Some idea that they might actually have to attack ships from the air might have helped (I mean, the Luftwaffe is going up against the worlds largest fleet, who'd have thought they needed anti-shipping tech.... The Luftwaffe had an abysmal record against ships off Dunkirk, in absolutely the most favourable circumstances for them. Closing off the channel... not going to happen.
Click to expand...
The Germans sank over 200 ships during the evacuation of France, just because not all of these were naval vessels it doesn’t mean they were not useful vessels. Throughout July the Luftwaffe sank or damaged a further 135 ships in British waters … again not all were RN ships however the Luftwaffe’s orders were to target merchant vessels not warships. As far as Dunkerque is concerned people often forget that the British actually had local air superiority during the evacuation which limited the Luftwaffe’s effectiveness greatly. The Germans were at the limit of their range whilst the RAF could fly from bases just 30-40 miles away. Whilst the evacuation started on 26th May it wasn’t until 1st June that the Germans could concentrate on stopping the evacuation due to the weather and other commitments.
 

Saphroneth

Banned
Julius Vogel said:
I wonder if it would help if the Germans somehow were required to stage several contested amphibious invasions during their Spanish frolic. Whilst perhaps unlikely, it may at least give them a slightly better idea of how these things work/how to do it better.

Probably wouldn't help a lot
Click to expand...

Given what Spain is shaped like (basically a square), there's no especial reason for a land-based power like Nazi Germany to be thinking in terms of amphibious operations. Fight your way there by land!
They would have to do river crossing operations, but that wouldn't help here.
 
ScrewySqrl

ScrewySqrl

von Adler said:
The big problem for the Germans is transport capacity and how to protect it.

The Luftwaffe probably could establish temporary air superiority over the landing zones. They probably could keep all but a few destroyers out against the landing fleet.

However, with the barge fleet gathered, the Germans were not only hurting their economy (the barges were needed for riverine transport), they also lacked the ability to get reinforcements and above all supplies across the channel.

The barges were completely dependent on calm weather, and a single MTB or destroyer getting through to the barge fleet would not need to shoot the barges up - it could simply speed past and let its wake waves make the barged capsize and sink.

What the Germans do need for a successful Sea Lion:

1. Fighters with longer range so they can stay over Britain longer (to force the RAF to move their air bases further north and have a slightly longer response time).

2. Radar on par with the British - probably in mobile stations that could be quickly moved to France, which was very rare 1940.

3. Many more air transports and their airborne forces not chewed up in the Netherlands (for dropping two airborne divisions AND supplying the troops).

4. A much stronger navy, especially in mining and transport. The Germans need to be able to drop mines to almost shut the English Channel off. They also need to be able to defend those minefields. They need to be able to transport a strong force across the channel and supply it. That will require purpose-built military transports. The Germans did build quite a few nice landing and transport ships, with the first ones arriving 1941 and used in the Baltic and on the rivers of Europe (the Yugoslav navy continued to use a few up to the 1980s).

http://www.german-navy.de/kriegsmarine/ships/landingcrafts/

The problem with all of these requirements is,

A. They don't happen in a vacuum. The western allies and especially Britain will respond in kind.

B. It requires several years of preparations. No-one expected the French to fall in a few weeks, not even the Germans. And no-one expected the British to carry on fighting if they did. Germany did not have a requirement for naval landing capacity 1935-1940.

C. All resources given to any programs along the note above will be taken from somewhere else, which might weaken the German ability in other fields, which might change history up to 1940.
Click to expand...

I agree with much of this, except that the Luftwaffe could not keep the RN out of the Channel.

If you give the Luftwaffe Stukas the luck of the Americans at Midway, there are literally too many warships in the Royal Navy to get them all before they are in amongst the transports for slaughter. The Navy isn't going to allow the invasion to land to spare ships from sinking.
 

King Augeas

Timing of the attack is a real problem, with regard to military strength. The winter of 1940 get in the way too, because a winter invasion is just insane.

I suspect that waiting to build up invasion strength helps the UK more than Germany, because the UK is making good the Dunkirk losses and regaining political composure. So, with invasion in Octoberish onwards ruled out by weather fears, Germany has to wait until, what, May? I recall a 1941 Sealion story where this was explored - ah here it is - http://warships1discussionboards.yuku.com/topic/22430/Sealion-1941-Part1a

But by Spring 1941 surely the UK is well prepared to stop an invasion, and the gap between defensive capability and invasion strength is only getting larger. So by that logic, time is against Germany and nothing that they can design, plan or build will help. The point is that it isn't about what Germany needs to attack, it's about what the UK has to defend with, so going earlier is better.
 

Astrodragon

Ian Hathaway said:
This is a Myth …

The Germans did have radar located on the French coast and in some respects it was more advanced than the British.

There were at least 500 Ju52 available with a handful of other transport aircraft and an undisclosed number of gliders.

The Germans sank over 200 ships during the evacuation of France, just because not all of these were naval vessels it doesn’t mean they were not useful vessels. Throughout July the Luftwaffe sank or damaged a further 135 ships in British waters … again not all were RN ships however the Luftwaffe’s orders were to target merchant vessels not warships. As far as Dunkerque is concerned people often forget that the British actually had local air superiority during the evacuation which limited the Luftwaffe’s effectiveness greatly. The Germans were at the limit of their range whilst the RAF could fly from bases just 30-40 miles away. Whilst the evacuation started on 26th May it wasn’t until 1st June that the Germans could concentrate on stopping the evacuation due to the weather and other commitments.
Click to expand...


Ian, you wanting it doesn't make it so.

(1) You've obviously never been on a destroyer-sized ship at full throttle. The wake (and the wake disturbance) is impressive. Easily enough for a barge. And even those with enough freeboard have issues, they are going to get tossed around. I have a suspicion the troops untrained in loading ships wont have everything fastened down properly...

(2) With all the destroyer trips to and from Dunkirk, remind me again how many were disabled/sunk at sea (even if we include those stopped taking on troops, its small). The Luftwaffe simply wasn't geared up for naval warfare in the summer of 1940.
And no, they didn't 'just target merchant ships' off Dunkirk. They went for anything afloat (quite sensibly, as all the ships were loading troops)
 

Saphroneth

Banned
ScrewySqrl said:
I agree with much of this, except that the Luftwaffe could not keep the RN out of the Channel.

If you give the Luftwaffe Stukas the luck of the Americans at Midway, there are literally too many warships in the Royal Navy to get them all before they are in amongst the transports for slaughter. The Navy isn't going to allow the invasion to land to spare ships from sinking.
Click to expand...

Ships are there to be used.
Or, as ABC would say, "It takes three years to build a ship. It takes three centuries to build a tradition."
 

Ian Hathaway

Astrodragon said:
Ian, you wanting it doesn't make it so.

(1) You've obviously never been on a destroyer-sized ship at full throttle. The wake (and the wake disturbance) is impressive. Easily enough for a barge. And even those with enough freeboard have issues, they are going to get tossed around. I have a suspicion the troops untrained in loading ships wont have everything fastened down properly...

(2) With all the destroyer trips to and from Dunkirk, remind me again how many were disabled/sunk at sea (even if we include those stopped taking on troops, its small). The Luftwaffe simply wasn't geared up for naval warfare in the summer of 1940.
And no, they didn't 'just target merchant ships' off Dunkirk. They went for anything afloat (quite sensibly, as all the ships were loading troops)
Click to expand...
It's not what I WANT it's what happened. I was trying to point out that the Luftwaffe's task was not as simple as everyone makes out at Dunkerque. The fact they sank as many ships as they did is a miracle considering RAF air superiority, the weather and conflicting priorities for resources. As we know of the destroyers used 45% were sunk or put out of service, which I think is pretty good odds under the circumstances.

Sorry if I caused confusion by the way, when I said they were targetting merchant ships only I meant in July not during the evacuation, I probably should have seperated those sentences.
 
ScrewySqrl

ScrewySqrl

Ian Hathaway said:
It's not what I WANT it's what happened. I was trying to point out that the Luftwaffe's task was not as simple as everyone makes out at Dunkerque. The fact they sank as many ships as they did is a miracle considering RAF air superiority, the weather and conflicting priorities for resources. As we know of the destroyers used 45% were sunk or put out of service, which I think is pretty good odds under the circumstances.

Sorry if I caused confusion by the way, when I said they were targetting merchant ships only I meant in July not during the evacuation, I probably should have seperated those sentences.
Click to expand...

there is also a bit of a difference between standing in a harbour loading troops, and steaming full speed, and maneuvering.

Still even if 45% of the destroyers in the RN's North Sea and channel fleet were sunk, if it prevented an invasion, the exchange would be well worth it. And it would take somewhat more bombs to get the cruisers, battlecruisers, and battleships, plus every plane in the fleet air arm, and all the small ships (escort corvettes and PT boats would be pressed in to stop th invasion)
 
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Gannt the chartist

500 Ju 52 - sounds a lot like total A/C on strength around 10 May 40. I have 225 serviceable as at 17 August. I expect that excludes 50 odd in Scandinavia but still.
 

Ian Hathaway

Gannt the chartist said:
500 Ju 52 - sounds a lot like total A/C on strength around 10 May 40. I have 225 serviceable as at 17 August. I expect that excludes 50 odd in Scandinavia but still.
Click to expand...
It could even be more ... Alfred Price in his book "The Luftwaffe Data Handbook" claims there are 226 servicable transport aircraft in frontline units. However HQ staff were maintained to supplement this with a further four Geschwade drawn from training units at short notice. Each Geschwade had a nominal strength of 90 aircraft giving a total of an additional 360 (max). 226 + 360 = 586 ... so I think I've been conservatively realistic in my estimate of 500.
 
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