ships needed for Sealion

[cavan]

Hello,
I am looking for any information about what ships the Kreigsmarine could have had to increase their chances of success in Sealion. Are there any books out there or websites that talk specifically about the weakness of the Kreigsmarine in this undertaking? (I am trying to write a paper on hypothetical action)
thank you,
Cavan Fitz

[Tiornu]

The Germans did not even approach having the necessary vessels--that includes amphib-warfare vessels, combat ships, and support units. I don't know where you'd start in pinpointing the areas of weakness. Destroyers, maybe? How many destroyers were there in service in the entire KM, ten? How many dozens of destroyers did the RN have operating around the British Isles?

[ptdockyard]

I believe Peter Kemp wrote an excellent book on this. Check Amazon.com.

[Black Baron]

LST's & the fast shallow draft supply boats they had in med which could carry at least one tank would be good adds.

[Paul Lakowski]

The Germans did not even approach having the necessary vessels--that includes amphib-warfare vessels, combat ships, and support units. I don't know where you'd start in pinpointing the areas of weakness. Destroyers, maybe? How many destroyers were there in service in the entire KM, ten? How many dozens of destroyers did the RN have operating around the British Isles?

No disrespect intended but that lack of amphibious ships didn't seem to adversly effect germanies chances to invade Norway.

I find it very disturbing to contrast modern and contemporary views of this event. The people I spoke to [some who were military at the time ],generally knew that nothing could have stopped the nazies if they seriously wanted to invade the UK. NOTHING, not the RN or RAF would have saved them. Once the germans landed britain would have collapsed just like france.

Contrast this with the modern confident view of invulnerablity and its quite sobering. People need to understand how much of a near run thing it really was. I pondered this question back in the 1970s with the Soviets and NATO. IF the soviets could indeed overrun europe, who we seriously have been able to stop them from invading the UK? In my youthly arrogance I believed we could...now I'm not so sure.

[Tiornu]

Fortunately we're not limited to the one-sided knowledge available to the folks at the time. When you read about the Battle of Midway, you'll find Americans worried about a Japanese strike against the US West Coast, something that was far beyond anything the IJN could have pulled off. After Japan's string of brilliant victories, the victims were starting to imagine Japan could do anything it wanted. However, there's little to be learned from looking at Britain's fear while ignoring what the Germans thought. They knew Sealion was hopeless, not even worth serious consideration.
Norway is instructive on the Sealion issue. The Germans were attacking a neutral without warning, a country with minimal military forces and lacking any sort of mine defense. Even so, they suffered extreme ship losses. The contrasts with an attack on Britain are stark. We can note also the difference in delivery of the invasions forces as planned for Sealion.

[Sam H.]

Its important to take the action beyond the landing. Even if the Germans managed to get a few divisions on shore, the enourmous effort required for Normandy shows that the Germans never could have supported those units. So if Britian doesn't collapse like a house of cards, the Germans lose all the troops they land - most likely within a week.

[Black Baron]

An interesting question to be sure. below is what they did put together for a cross channel trip. 140 tons of material is nuttin to sneeze at. Capture of a usable airfield would be essential to fly in extra supplies. I would imagine U-boats would do commando raids on radar installations prior to launch.



The Naval Landing Crafts - called "Marinefahrprahm" in German were the largest landing craft used by the Kriegsmarine. Although required for Operation Sealion (Invasion of England) in 1940, the first of this transport ships were delivered in 1941. The development of this ship went through several Types (A-D), whose size and armament grew from class to class. They were mainly used for transport and supply duties and not for their initial invasion role and could transport 200 Soldiers or 140 tons of equipment, including Tiger tanks. Marinefahrprahme were used in almost all Kriegsmarine operational areas: the British Channel, the North sea, the Baltic, the Mediterranean and the Caspic and the Black sea

Very shallow draft as well which made it impervious to torpedo attack.

Last

[Black Baron]

Here's what the Viking did regarding supplies. I don't know exactly when it became operational, & would be easy target, but with fighter escort, some would get across.


The Viking flying boat weighed 30.659 kg, ( 67.572 lbs ), almost as much as the B-29! By the end of 42 it had carried 1377 tons of cargo, 17.000 troops, & 2400 casualties in the Mediteranean.

[Andy H]

I find it very disturbing to contrast modern and contemporary views of this event. The people I spoke to [some who were military at the time ],generally knew that nothing could have stopped the nazies if they seriously wanted to invade the UK. NOTHING, not the RN or RAF would have saved them. Once the germans landed britain would have collapsed just like france

I'm sorry Paul but I find that statement amazing.
Landing is one thing, actually conquering is another.
The German logistical tail was made of glass.
Germany's best and only real chance of success was a on the hoof attempt after Dunkirk.

[Groscurth]

[quote="Tiornu"] How many destroyers were there in service in the entire KM, ten? [/quote]

Here you haver the answer, great site about the Kriegsmarine Btw.
Greetings,

Groscurth

[Groscurth]

[quote="Tiornu"] How many destroyers were there in service in the entire KM, ten? [/quote]

Here you haver the answer, great site about the Kriegsmarine Btw.
http://www.german-navy.de/kriegsmarine/ ... index.html
Greetings,

Groscurth

[ptdockyard]

Even if the MFPs were available, they would not have ensured success in Sealion. An invasion in 1940, with unpowered, towed barges, few naval assets and dubvious air superiority would have been a disaster.

MFPs were NOT immune to torpedoes. Only Mark VIII US PT torpedoes had singular lack of success and this changed in 1944 with the use of Mark XIII torpedoes. Many were sunk by British submarines and late war British MTBs using surface running torpedoes or magnetic detonators. Soviet subs bagged a few in the Black Sea also.

One interesting twist has been the subject of a novel titled "S-day." The Author, James Thayer, had the Germans delay their invasion of Russia and spend all of 1941 wearing down the UK. In this book the invasion takes place in mid 1942 with limited US assets backing up the British.

Dave G.

[Zebedee]

I go with Churchill on this one (as recounted in Volume 2 of his history of WW2). I will use the information provided by Churchill as the primary source for the following answer.

As far as I can recollect, the Battle of Britain was a serious attempt to remove the RAF as a factor in an invasion. The attempt failed.

With even the German High Command not particularly at ease with Operation Sealion, I can't see any justification in the belief that such an invasion would have been successful beyond a rapidly repulsed landing. (This is, of course, assuming that the Royal Navy had not noticed the invasion force clearing away the minefields).

That the German forces had the shipping to carry out an invasion is beyond a doubt. But the shipping would have just about have carried only the first wave in the plan set out in Sea Lion. Without air superiority over the Channel and beachheads, without removing the considerable factor of the Royal Navy and without being able to rapidly reinforce any footholds, I cannot see how an invasion would have any likely chance of success. As one German general commented upon seeing the plan, "I might as well send those troops directly to the sausage factory".

In answer to Cavan's original question, as Tiornu said, several dozen destroyers would undoubtedly have helped. But the weakness of the plan did not lie with the Kriegsmarine alone. Look at how difficult D-Day (and the breakout) was and the resources available to the Allies to carry it off successfully.

[Paul Lakowski]

You guys are focusing too much on the narrow military application of force here. Had the British army been crushed at Dunkirk instead of escaped, there would have been precious little to stop the Germans once they landed. Without an army to defend , the British moral would have collapsed and the country would have folded. Once an enemy has been defeated in battle , the immediate next step is to exploit , pursuit and roll up the enemies territories, that would have included the UK.

Its one thing to defiantly resist while fighter and bombers duke it out overhead, its quite another thing to resist a combined ground & air assault. Comparisons with Normandy are invalid since the Atlantic Wall was a serious military boundary manned and backed by an organized 'battle hardened armed forces' with years of experience , and time to be ready for war. UK had none of this in the summer of 1940, after the fall of France. In the first phase of BoB , the RAF was fighting for its life and would have been too tied up defending its assets to intervene much or risk losing airbases and squadrons on the ground , thus ensuring RAF defeat. Of course German investment in Strategic bombers would have achieved a similar end too.

Like wise a major ocean sortie of German KM capital ships would have similarly tied up the home fleet , until after the invasion had begun. Concentration of German U-boats utilizing both mining & torpedo attacks, could have erected screens to prevent interference from the local 'anti invasion' RN escorts fleets , especially since these appeared to have been much more effective in the first years of the war.

The Germans could have realistically thrown a division over in each wave plus supplies for several months. When these ran low on fuel & food or vehicles, they could be seized from the locals as they moved along. Any one resisting would be shot....that seems to have worked well in Europe and would have worked just as well in the UK.

Invasion planning envisaged 2 day turnaround between waves of troops landing, but it would be more like a week turn around per wave. There is little doubt they could get the ships across, but there is considerable doubt that the Luftwaffe or RAF could sink that many boats, that’s just wishful thinking.

What ever British ships the Luftwaffe did sink during Dunkirk, was no where near enough to halt the flood of boats each way and neither air power could seriously affect the out come. ...and they enjoyed local air superiority at the time. Bombers of the time had a very hard time sinking ships. The brits got across 400,000 troops in a week during Dunkirk. “Combined arms” is the nature of this type of operation, that’s how it worked in Norway with land sea and air components simultaneously conducted, which would be a closer model than Normandy.

Yes there were only 10 operational KM destroyers /torpedo boats after the Norwegian invasion, but there were dozens of 'channel destroyers too . Had this been a part of the realistic prewar planning of the invasion of France , back in the 1930s, sufficient numbers of escorts and landing craft could have been fabricated in time to suite the mission. Historically as it became apparent that the lack of investment or planning left the KM with insufficient escorts, the burden shifted to a singular one dimensional attack from the air which is always doomed to failure. That was the key failure on the Germans part and probably cost them the war. Germany could realistically defeat the Soviet Union or the western allies sequentially, but not both at the same time.

If your the British or American , you have to seize theater air superiority first since that’s you method of attack. But if you are the Germans you do both a the same time. The Germans didn’t spend weeks defeating the Polish , French or Soviet air forces BEFORE they invaded…they just did it as a part of the ongoing operational plan. Combined arms are the name of the game and if sufficient planning had been invested from the start, it was doable. As it was historically, Hitler 'believed' he would not have to go to war with the UK and could cut a deal when the time came, which is why planning for UK invasion was not included. Clearly this was another one of Hitler strategic blunder.