A Midget Submarine Raid On Scapa Flow in 1939

[oldironside]

Okay, I can't believe I'm about to do this, but I'm starting another Scapa Flow thread. At first glance this is slightly more realistic than Ovaron's magnum opus or that current business about gliders.

Whilst back in England last week I was lazing in front of the History Channel with a beer in one hand and a hideous sense of deja vu in my mind. "Oh, they do successful Sealion programmes on here?"

I then came across a half decent doc about the Japanese midget submarines that tried to infiltrate Pearl Harbor on Dec. 7th 1941. The thrust of their argument was that one out of four subs actually made it in and fired its two torpedoes (one of which missed).

Given Gunther Prien's successful infiltration of Scapa Flow in 1939, and the X-Crafts' actions against the Tirpitz, how possible do you board members think that an attacke by four or six or twelve midget subs in 1939 would have been.

On the plus side (from the Kriegsmarine's pov - I'm quite happy that the Allies won the war) the RN didn't expect any sort of sub attack on Scapa Flow, which is how Prien managed to get in. We also know from OTL that it was perfectly possible to smuggle a Type VIIB U-boat in unnoticed, so presumably a group of subs which displaced far less than U-47's 753 tons (for example, the Japanese Type A Ko-hyoteki-class displaced 46 tons).

On the downside, the KM has to face the horrendous unreliability of its torpedoes, the need to smuggle the subs unnoticed across the North Sea (lashed to other larger subs?) and the fact that no one seems to have thought of it until me (I googled it and found nothing).

So, guys, with a POD in 1918, could the KM have launched a successful midget sub raid on Scapa Flow? Knock yourselves out.

 

[Just Leo]

The Italians sank two battleships in Alexandria harbor, plus a tanker. Had the water been as deep as at Scapa, they wouldn't have been repaired in a year. Unlike Japanese midgets at Pearl, and British boats on Tirpitz, all the Italians survived.

 

[oldironside]

The Italians sank two battleships in Alexandria harbor, plus a tanker. Had the water been as deep as at Scapa, they wouldn't have been repaired in a year. Unlike Japanese midgets at Pearl, and British boats on Tirpitz, all the Italians survived.

Hmmm. I'm starting to think this is worryingly plausible.

 

[Just Leo]

Don't worry. The water's too chilly.

 

[hasdrubal barca]

Yippeeee

 

[water123]

I'd be more worried about the Italians up New York Harbour than in Scotland, but I don't see why the Italians wouldn't be able to. They were not good at that much in WWII, but using submarines to sink stuff was one of the things that they were, especially with German help.

Linky about New York: http://www.regiamarina.net/detail_text_with_list.asp?nid=99&lid=1&cid=4

 

[oldironside]

I'd be more worried about the Italians up New York Harbour than in Scotland, but I don't see why the Italians wouldn't be able to. They were not good at that much in WWII, but using submarines to sink stuff was one of the things that they were, especially with German help.

Linky about New York: http://www.regiamarina.net/detail_text_with_list.asp?nid=99&lid=1&cid=4

Scapa Flow would be a far better option than NY for an early chariot/midget sub attack. It's nearer and a successful raid could have shited the balance of power. If they'd got in, any ships sunk would hsve been lost - unlike Pearl or Alexandria.

 

[pdf27]

Didn't Prien have trouble with the currents getting in past the blockships? I half remember reading that he got in through a fairly narrow gap against a strong current - smaller submarines are going to have a much lower top speed and might not be able to make it.

 

[oldironside]

Didn't Prien have trouble with the currents getting in past the blockships? I half remember reading that he got in through a fairly narrow gap against a strong current - smaller submarines are going to have a much lower top speed and might not be able to make it.

It's a fair point, and relevant for putting a Type VII sub through the only feasible gap, but IIRC the map of Scapa Flow defences in 1939 showed multiple gaps to exploit becauye the RN didn't expect a chariot attack. Given that a large number of Reichsmarine officers were 'stationed' there in 1918-19, the KM must have had a decent working knowledge they could fall back on.

I'd post the map, b ut I'm on my phone. :-(

 

[TFSmith121]

Did the Germans HAVE any small submersibles in 1939, however?

Did the Germans HAVE any operational small submersibles in 1939, however?

If not, it's sort of like asking if the anchorage would be vulnerable to an attack by jet-propelled bombers in 1939...well, yes, but...

Given how many torpedoes Prien fired to even get Royal Oak, seems like a better plan would have been to send more than one Type VII submarine in after him...

The other question is that as bad as the loss of one of the RN's 22 capital ships was in 1939, and the fact the RN had to pull out until the base's defenses were improved, would the same resources devoted simply to merchant shipping have more of an actual impact?

Cripes, how many troopships were crossing the Channel with elements of the BEF in 1939?

The thing about special operations of any type is - although they can be useful if integrated into a larger "conventional" campaign - they rarely have the same level of impact on the battlefield that the same resources simply devoted to "typical" targets and/or forces might have...

Just something to keep in mind when it comes to this sort of "what if"...

Best,

 

[oldironside]

Well the answer to that is that the Germans didn't get into midget subs until 1943-44, but also that Italian and Japanese midget subs/chariots came as a nasty shock to their respective opponents. Why shouldn't a KM Streitwagen? The Italians and Japanese had and developed the idea. I do 't think it's a huge lleap for the Germans to have the idea. A more interesting questin would be "Why didn't it occur to the KM and why did they waste effrt on battleships that were strategically useless?" It's not like they didn't know how Scapa low was laid out.

 

[MattII]

If the Italians had midgets early, why couldn't the Germans have borrowed the designs and built their own?

 

[oldironside]

If the Italians had midgets early, why couldn't the Germans have borrowed the designs and built their own?

Or, the technology was so simple for an industrial nation with submarine experience l(I'm looking at you, Germany) that they could have done it with the will. Wether they could have organised the raid to sink enogh ships to make a difference is another question

 

[nbcman]

Or, the technology was so simple for an industrial nation with submarine experience l(I'm looking at you, Germany) that they could have done it with the will. Wether they could have organised the raid to sink enogh ships to make a difference is another question

Germany did develop a prototype 'midget' sub, the V-80, which was completed in 1940. It was a prototype which led to the XVII submarine class, not to a series of midget subs. It was an unarmed prototype so it could not have been used offensively in 1940 without significant modifications or a change to the design criteria before construction began in 1939.

The Germans did produce 'Chariots' or manned torpedoes, but they did not produce them until later in the war.

 

[MattII]

Or, the technology was so simple for an industrial nation with submarine experience l(I'm looking at you, Germany) that they could have done it with the will.

Technology and design are different things, Germany had all the technology to build a decent carrier, but even if the Graf Zeppelin had been completed it wouldn't have been such, because it wasn't a good design.

 

[AdA]

Type IIB Boats, being under 300t, could be an interesting compromise for this kind of mission, being small enough for easier use in confined waters than the Type VII, but a lot less complicated to get to Scotland than really midget submarines.

 

[Detlef]

Well the answer to that is that the Germans didn't get into midget subs until 1943-44, but also that Italian and Japanese midget subs/chariots came as a nasty shock to their respective opponents. Why shouldn't a KM Streitwagen? The Italians and Japanese had and developed the idea. I do 't think it's a huge lleap for the Germans to have the idea. A more interesting questin would be "Why didn't it occur to the KM and why did they waste effrt on battleships that were strategically useless?" It's not like they didn't know how Scapa low was laid out.

Because that war wasn´t supposed to happen (yet)?

Italy had as a serious threat in the Mediterranean the French and British navy so "chariots" to improve the odds make sense. Japan in the Pacific ocean faced the USA and Britain so they designed "midget subs".

Hitler didn´t want a war with Britain and he was perfectly happy with the Anglo-German naval agreement. So the early plans were for a balanced German navy capable of dealing with Poland and France.
It was only in late 1938 that he grasped that Britain was losing "patience" with him. That´s when he demanded a new naval program, the so-called Z-plan for a war with Britain. One group in the German navy wanted to concentrate on cruiser warfare and submarines, the other group supported a large battle fleet. With Hitler of course coming down on the side of gigantic battle ships. And that wasn´t supposed to be a problem because a war with Britain would only start after 1945. According to Hitler.
(Totally overlooked of course, that shiny large 1945 fleet would have needed the total 1939 German oil supply.)

So the German submarine force in 1939 was tiny. 57 submarines, only 22 of them ocean going type VIIAs plus 7 type IXAs. The rest were type II coastal subs. You´d need to modify 2-3 of the ocean going subs in 1937/38 to carry "chariots" in late 1939. Losing essentially 10% of your strength.
(The Japanese "mother" submarines carrying midget subs were with 2500 tons much larger than German ones.)

For your scenario to work you´ll need a change much earlier. And that will be difficult against the opposition of Raeder (balanced navy) and Doenitz (don´t want to lose any ocean going submarine for special operations). You´d need to invent a person in 1935/36 who can convince the navy and/or Hitler that a special operations group with 2-3 subs is a good idea. That would give you enough time for construction and training.

 

[TFSmith121]

The Type IIs are an interesting idea; the only

Type IIB Boats, being under 300t, could be an interesting compromise for this kind of mission, being small enough for easier use in confined waters than the Type VII, but a lot less complicated to get to Scotland than really midget submarines.

The Type IIs are an interesting idea; the only question being the quality issues in the German torpedoes in 1939-40, it would probably take at least a couple to get the results Prien's single Type VII did...

Best,

 

[I want to learn]

I think it's within the realm of plausibility for Nazi Germany to use submarine-based special forces to attack Scapa Flow, but I don't see how they could accomplish more than what Prien did. He permanently sank a capital ship with no losses. British attacks only damaged the Tirpitz, same as Italian attacks on Queen Elizabeth and Valiant. Decima Flottiglia MAS in particular had experience from several failed attempts before their success at Alexandria. A bungled German frogman attack could be less productive while still alerting the British to their insufficient submarine defenses. There's also the question of where these elite German forces and their expensive fancy gizmos would come from, and why it's worthwhile to develop those while a standard U-boat did the job perfectly fine.

 

[I want to learn]

I think it's within the realm of plausibility for Nazi Germany to use submarine-based special forces to attack Scapa Flow, but I don't see how they could accomplish more than what Prien did. He permanently sank a capital ship with no losses. British attacks only damaged the Tirpitz, same as Italian attacks on Queen Elizabeth and Valiant. Decima Flottiglia MAS in particular had experience from several failed attempts before their success at Alexandria. A bungled German frogman attack could be less productive while still alerting the British to their insufficient submarine defenses. There's also the question of where these elite German forces and their expensive fancy gizmos would come from, and why it's worthwhile to develop those while a standard U-boat did the job perfectly fine.