The Italian Navy and Operation Sealion 1940

[taylorjohn]

Most skepticism regarding the chances of a successful German invasion of the British Isles in 1940 is related to the enormous disparity in size between the RN and the KM.

However, the Italian Navy at this time was the fourth largest in the world.

As an alternative historical scenario, for the period June to Dec 1940, supposing, for the sake of argument, that Hitler had persuaded Franco to allow German forces to enter Spain and capture Gibraltar in the Summer of 1940.

If this had happened the Straits for Gibraltar would have been opened to Axis shipping and this, in turn, would have enabled the Italian Navy to provide the naval protection which the German invasion fleet needed.

If this had happened could operation Sealion have succeeded?

[LWD]

No. Or at least vary unlikely. First of all it is doubtful that the Germans could have gotten the force and plan in place to take Gibralter by the Summer of 1940. If they did then it's still a very short time to plan an invasion as big as Sea Lion (weather alone would make it difficult to impossible by mid October. If Gibralter falls then the force there would at least in part be in Britain as would some of the forces sent to Africa. Also remember that the Germans were loosing the BOB. So with or without the Italians they aren't going to have air superiority. Then while the Italians had a decent size navy many of their ships were rather short ranged. This could be taken care of by resupplying them in France but that requires supply depots to be set up ie more time. As time goes on the RAF becomes relativly stronger than the LW and this will continue through the winter. The British army is also reequiping and building up during this time frame so in order to have any real chance the Germans have to get a bigger force ashore faster than they planned. Note that even the orignal force is marginal in a best case invasion. In the mean time the Italians are still badly outnumbered by the RN and given the vulnerability of their new BBs to torpedos operating near British home waters doesn't sound like a prescription for a long life.

[taylorjohn]

No. Or at least vary unlikely. First of all it is doubtful that the Germans could have gotten the force and plan in place to take Gibralter by the Summer of 1940. If they did then it's still a very short time to plan an invasion as big as Sea Lion (weather alone would make it difficult to impossible by mid October. If Gibralter falls then the force there would at least in part be in Britain as would some of the forces sent to Africa. Also remember that the Germans were loosing the BOB. So with or without the Italians they aren't going to have air superiority. Then while the Italians had a decent size navy many of their ships were rather short ranged. This could be taken care of by resupplying them in France but that requires supply depots to be set up ie more time. As time goes on the RAF becomes relativly stronger than the LW and this will continue through the winter. The British army is also reequiping and building up during this time frame so in order to have any real chance the Germans have to get a bigger force ashore faster than they planned. Note that even the orignal force is marginal in a best case invasion. In the mean time the Italians are still badly outnumbered by the RN and given the vulnerability of their new BBs to torpedos operating near British home waters doesn't sound like a prescription for a long life.

I disagree - I see, no reason, why the Germans, at the beginning of July 1940, could not have thrown together a scratch force to take Gibraltar if they had wanted to do so, provided, Franco had allowed the passage of German ground and air forces through Spain.

The numerous French ports along the Atlantic coast and in Brittany should have been in a position to accommodate the Italian Navy (or at least part of it).

Perhaps, in the above scenario, I should also have mentioned earlier German invasion preparations say around the beginning of July.

In this case, ‘Sealion’ would then have been ready by the beginning of September when the Luftwaffe was starting to gain the upper hand during the BOB.

At this time, the British Army was still in the process of reequipping after its heavy losses in material at Dunkirk and was widely dispersed throughout the British Isles.

If you add in the Italian Navy to the existing the defensive measures the Germans had in place to protect their invasion fleet (mine belts, submarines, the Luftwaffe, coastal guns, KM naval escorts, diversionary measures etc) I believe, Sealion might well have succeeded.

[LWD]

I disagree - I see, no reason, why the Germans, at the beginning of July 1940, could not have thrown together a scratch force to take Gibraltar if they had wanted to do so, provided, Franco had allowed the passage of German ground and air forces through Spain.

Even the Germans were surprised with the speed of their advance across France. So when France falls in late June there will be minimal if any plans in place. Now the Germans have to either negotiate with two "neutral" countries (Vichy France and Spain) to move their forces to Gibralter. It has been mentioned that the supply routes across Spain were not the greatest a sea movement is possible but requires obtaining the shipping and risk interception by the RN. So either you have to hold forces back from the invasion of France or wait until it's over to see who's in shape to attack Gibralter. Then you have to resupply and refit those forces plan and execute thier movement to Gibralter. Now the British are going to see this coming as you simply won't be able to hide this large a troop movement. Once at Gibralter remember it's a fortress and has considerable support from naval gunfire. It's not going to be an easy nut to crack. At the very least the forces used won't be available for Sea Lion at least if its to occur in September and probably not in October. I franly can't see the Germans starting the campaing until August at the earliest.

The numerous French ports along the Atlantic coast and in Brittany should have been in a position to accommodate the Italian Navy (or at least part of it).

The problem is the unique Italian supplies such as ammo and spair parts. You have to figure out where your going to base the ships and send the stuff their in time. In this case you are using a significant amount of logistics assets as historical to prep for Sea Lion. You are also using a bunch more for the Gibralter campaign, now you want to use even more to set up Italian supply dumps in France. I'd have to see some proof that the German/Italian supply system was up to this. Note that the Italians aren't going to be happy about leaveing Italy unprotected from the British forces in Egypt.

Perhaps, in the above scenario, I should also have mentioned earlier German invasion preparations say around the beginning of July.

There is a limited amount of planning you can do before you know what happens in France.

In this case, ‘Sealion’ would then have been ready by the beginning of September when the Luftwaffe was starting to gain the upper hand during the BOB.

But they never were. The LW never gainded the "upper hand" and indeed their postion deteriated as the BOB went on.

At this time, the British Army was still in the process of reequipping after its heavy losses in material at Dunkirk and was widely dispersed throughout the British Isles.

But it was still much stronger than any force the Germans could land. By Setpember a signifcant amount of requipping had already been acomplished.

If you add in the Italian Navy to the existing the defensive measures the Germans had in place to protect their invasion fleet (mine belts, submarines, the Luftwaffe, coastal guns, KM naval escorts, diversionary measures etc) I believe, Sealion might well have succeeded.

The presence of major Italian units would simply have insured that the RN committed major units and proably given some deserving British submariners a lot more allocades. What forces do you propose the Italians send? Have you really looked at what the Germans had? By the way the Germans apparently didn't have any where near enough mines to build the belts required by the plan. By September the KM was already complaining that they were behind schedule in their own anti mine efforts supporting the invasion due to lack of LW support. The British coastal guns were in a much better postion by the way to paly a part than the German ones. Sea Lion was a pipe dream most of the German military knew it from the beginning.

[JonS]

On the other hand, what, really, was in the way of the Italian Navy just blowing through the Straits? I'm genuinely curious about this - all these what if's are founded on the presumption that Gibralter had to be taken in order for the RM to get out into the Atlantic, but is that really the case?

AFAIK there was no mine barrage across the strait, and the RAF presence in Gibralter can't - I think - have been very strong. Useful for recon, but not so great for attacking. OTOH, the RM would have essentially no air cover, so maybe a small RAF/FAA force there could be quite effective.

I suppose the RN units - Force H - would have been a nuisance, but the point isn't to engage and defeat Force H, it would be to get through to the other side and leg it off to France. Besides, how big was Force H in Aug-Nov 1940 anyway? Sure there'd be losses, but in the larger scheme of thinsg the purpose of the Navy is to fight.

I guess, from Italy's POV that approach - blowing through the straits - would be a non-starter since it would denude the Med of RM force, and bring the RM back into the Med in the event that SEALION failed would be a rather more difficult challenge. Also, there isn't a lot of incentive for Italy to risk its fleet in support of a German operation in Britain ... although if successful it would have given them a much freer hand in the Med.

Flip.

Flop.

I don't know.

OTOH, this point ...

The presence of major Italian units would simply have insured that the RN committed major units and proably given some deserving British submariners a lot more allocades. What forces do you propose the Italians send? Have you really looked at what the Germans had? By the way the Germans apparently didn't have any where near enough mines to build the belts required by the plan. By September the KM was already complaining that they were behind schedule in their own anti mine efforts supporting the invasion due to lack of LW support. The British coastal guns were in a much better postion by the way to paly a part than the German ones. Sea Lion was a pipe dream most of the German military knew it from the beginning.

... is granted. Even a successful blow-through wouldn't have mattered. Which also goes to the grave risk that participating in SEALION would have represented to the RM and Italy.

Still would, or perhaps could a blow-through have succeded?

Regards
Jon

[taylorjohn]

The Italian navy was large - they could have commited a large force to support the German invasion of the Britain and still retained enough ships to have covered their own coastline and forces in North Africa.

[JonS]

So you're suggesting that they should keep enough back to ensure SEALION still fails, but not enough to secure the Med (given that in the OT they didn't have enough anyway)?

Interesting strategy, but ok. What is the is the objective of this strategy?

And more to the - well, my - point; could this "large but not large enough force" have gotten through the Straits?

Cheers
Jon

[taylorjohn]

So you're suggesting that they should keep enough back to ensure SEALION still fails, but not enough to secure the Med (given that in the OT they didn't have enough anyway)?

Interesting strategy, but ok. What is the is the objective of this strategy?

And more to the - well, my - point; could this "large but not large enough force" have gotten through the Straits?

Cheers
Jon

I think you are missing my point - I am suggesting that the RM was large enough to have provided Sealion with enough ships to protect the invasion fleet (in addition to what the Germans already had and yes the Germans DID have enough mines) as well covering the Italian coastline and North Africa.

I think it is safe to say that a successful invasion of Britain would have greatly aided the Axis cause in the Med.

If Gibraltar had been captured, yes the RM could have gotten through.

[JonS]

If Gibraltar had been captured, yes the RM could have gotten through.

That much is obvious.

Just as obvious as the fact you didn't read what I wrote but felt compelled to comment on it anyway :roll:

My question was whether the RM could have gotten through the straits without Gibraltar being captured by the Axis.

[taylorjohn]

My question was whether the RM could have gotten through the straits without Gibraltar being captured by the Axis.

The Luftwaffe could have bombed Gibraltar to knock out the British coastal guns covering the Straits and neutralize the RN base.

Not sure, how successful that would have been though.

John

[JonS]

Based from where?

Besides, wasn't the GAF kinda busy at the time, failing to acheive air-superiority over SE England?

[Tim Smith]

As an alternative historical scenario, for the period June to Dec 1940, supposing, for the sake of argument, that Hitler had persuaded Franco to allow German forces to enter Spain and capture Gibraltar in the Summer of 1940.

Do you have any ideas on how Gibraltar could be capured in summer 1940 (July or August?)

I'm thinking that the Fallschirmjager have a) suffered quite heavy losses in their assault on Fortress Holland, and b) need to conserve and prepare their forces for Operation Sealion.

So that means paratroopers may not be available (unless they are Italian paratroopers.)

Gibraltar is a very tough target for a paratroop landing anyway, due to the rocky terrain - the Axis might be better off without them.

Which in turn means that the capture of Gibraltar would have to be done by infantry and artillery. (I'm assuming that Panzers will also have extreme difficulties in that terrain.)

And the British would have been quite well prepared for an infantry assault on the Rock - that's the scenario they would have trained and prepared for.

A swift 'surprise' infantry assault on Gibraltar could well be extremely bloody, and might well be a failure.

The safest way to deal with Gibraltar is to put it under siege and bombard it for several weeks with very heavy siege artillery - as with Sevastapol in 1942 - and only after that send in the infantry. However this strategy might take too much time to set up and implement fully before Sealion is due in September 1940.

[JonS]

... yes the Germans DID have enough mines [to seal the English Channel]

Facts not in evidence, your honour.

Besides, isn't a German mine barrier - at the western end at least - going to make life a little interesting for their Italian Allies?

[Jon G.]

Ah, another deus-ex-machina way of making Seelöwe succeed I think we have been over magic transport U-Boats, magic mileage Ju-52s with magic steel containers, and magically deliberately grounded transport ships.

This scenario is more credible, at least. My problem with this particular scenario isn't that it is unrealistic or impossible, but rather that it pre-supposes a level of Axis cooperation which just wasn't there. Mussolini wasn't privy to Hitler's plans - he was given a starting date for Seelöwe which turned out to be a mere declaration of intent. Mussolini's contribution to ultimate British defeat was to order Graziani to attack Egypt - something the Italian army in Libya was just barely capable of. The comparatively modest task of keeping the supply line to Libya open was difficult for the Italians, not least because their navy was always short on oil.

Probably they could have found the oil for a joint Axis Seelöwe, but it would have been a great gamble, which would have left Italy itself in general and her potential Balkan flank in particular wide open. How, BTW, does the French fleet at Mers-el-Kebir fit into the overall picture? With the Med denuded of Axis ships, would the British have attacked the French ships in North Africa? Would Hitler supply the Italians with the oil they needed assuming the RM offered him naval help which he never asked for?

[Andy H]

Just what is the makeup of this proposed Italian support?

Regards

Andy H