Possible Submarine carriers & submersible smallcraft.

For a timeline outline I am working on:
I'm looking for alternative submersible smallcraft, to be carried to sea by, launched from (and recovered by), a 'mother ship' submarine. Missions types would include:

Alexandrian/Scappa Flow raiders. Small submersible craft attacking major fleet units at anchor - because smaller is better when trying to penatrate the anti-submarine defenses, and plan to have several infiltration mini subs involved in the effort-all of which are expendable. Mother ships supporting them until harbour is filled, then go in...
{This type needs no high speed, nor extended range, nor extensive weapons load} Size medium.

Anti Anti-Submarine ship. Very fast submerged speed w/powered mines that get to target depth for pattern detonation.
{This type needs (underwater) speed as its prime requirement, along with enough weapons load to make repeated runs} Size small.

Submersible torpedo rack. A submersible that is essentially just a bunch of torpedo tubes that can all be launched at once, for saturation attacks upon a convoy.
{This type needs a large weapons load w/total launch capability. Just enough speed to get into position, but a long enough range/duration to permit usefull station keeping} Size large.

As always, the PoD is that of a 1919 Germany, with a group of rich military/industrialists leading the charge to develop new weapons of war to enable Germany to fight and win a revenge war against the UK & France. This thread is for the undersea portion.

If you have any ideas for designs, doctrines, secret weapons development strategies etc...

Looking forward to your input folks.
 
Aircraft need to be light to be able to take off, submarines need to be strong to resist water pressure. Try to mix the two functions and you end up with a machine that is absolutely crap at both.
 
OOOpppsss!!!

Seems I did it again. The time frame is uspposed to be in line with otl WWII, with the beginning of R&D taking place in 1919.

OTOH, in the line with previous offerings:

Skydiver.jpg_2D00_675x550.jpg
 
Seriously though, I am looking for some ideas along the lines posted in OP. Give me some feedback on possible designs for the missions listed there, as well as other missions that one could reasonably expect to be able to pull off with the right custom designed submersibles.
 

BlondieBC

Banned
Use a disguised freighter/AMC to sneak the ships into range. It will largely be a one way mission anyway, so why bother with all the bizarre designs. A crane capable of lowering a midget submarine and a cargo hold that can hold them is all that is required.
 
Use a disguised freighter/AMC to sneak the ships into range. It will largely be a one way mission anyway, so why bother with all the bizarre designs. A crane capable of lowering a midget submarine and a cargo hold that can hold them is all that is required.
Interesting idea, that. I have to admit that I had not thought previously about combining a 'Q' ship with the submersible smallcraft. I'll have to give that some thought. On the other hand, once a war breaks out, I fear that the 'Q' ships would be soon dispensed with upon being boarded and inspected. Still, the same might be said for any AMC no matter what it's design or configuration.

My curiousity was peaked some time ago when I read about the time it took between shots, and I thought to myself "What if a submarine didn't have to try and get a really good shot in, but could instead just spray a large number of torpedoes into the path of an oncoming convoy?" Then I thought about having say 1/2 dozen small submersible craft that were mainly just torpedo tubes (in trainable housings) that could be rapidly fired. And further, what if you had 6 'mother ships' each with 6 such craft?

The idea here is to launch a massive number of torpedoes, and let nature take it's course.

Could it be possible to have a turntable type of torpedo tube setup on such a craft? What about a 5/6/5 triple, with it being on a submersible I would think this might be possible. What if each such craft had three of these launchers on it's centerline?

A wolfpack of 6 such submarines would thus be able to deploy 36 of the submersibles, each of whom could potentially salvo 48 torpedoes during an attack.

Anyway, the TL outline I am working on is going to have efforts made to 'work out' some alternate designs/tactics, even if they decide not to build them, it should still be fun writing about the attempt.:D
 

BlondieBC

Banned
Interesting idea, that. I have to admit that I had not thought previously about combining a 'Q' ship with the submersible smallcraft. I'll have to give that some thought. On the other hand, once a war breaks out, I fear that the 'Q' ships would be soon dispensed with upon being boarded and inspected. Still, the same might be said for any AMC no matter what it's design or configuration.

It is a one time trick. For examples of others look at Italy in WW2. The used a old rusty freighter that was run aground in Spain to attack Gibraltar. At night, divers left a small hidden door at the water line and attached mines to UK shipping. The mines were set to go off after the ships had traveled 10's of miles, so the UK just thought it was mines floating in the Straights.

My curiousity was peaked some time ago when I read about the time it took between shots, and I thought to myself "What if a submarine didn't have to try and get a really good shot in, but could instead just spray a large number of torpedoes into the path of an oncoming convoy?" Then I thought about having say 1/2 dozen small submersible craft that were mainly just torpedo tubes (in trainable housings) that could be rapidly fired. And further, what if you had 6 'mother ships' each with 6 such craft?

The idea here is to launch a massive number of torpedoes, and let nature take it's course.

Could it be possible to have a turntable type of torpedo tube setup on such a craft? What about a 5/6/5 triple, with it being on a submersible I would think this might be possible. What if each such craft had three of these launchers on it's centerline?

A wolfpack of 6 such submarines would thus be able to deploy 36 of the submersibles, each of whom could potentially salvo 48 torpedoes during an attack.

Anyway, the TL outline I am working on is going to have efforts made to 'work out' some alternate designs/tactics, even if they decide not to build them, it should still be fun writing about the attempt.:D

I am not sure spraying torpedoes helps. You want to get close and fire an good aimed shot, which a regular submarine does fine.

Also another gimmick is just to preposition a freighter is some small anchorage somewhere that would be a mobile base for submarines. It is what I used in my TL for WW1. It has some limited potential without a permanent base, which my TL had ,but yours will not.

You will find getting in torpedo range is more of an issue than the spread. Unless you have a Jutland like battle in WW2, and you will not, then mass attack does not mater much. You real issue will be bringing the capital ships to an area to attack. For example if you had U-boats that were faster than the Bismark, you could have them form a bubble around the Bismark, and make the UK life quite hard. The issue is you can't build a 35+ knot U-boat. You should probably focus on how to do a mass attack on something like Scapa Flow. I think you will find the Italian attack on Alexandria to be about the ideal method. The problem is that once used, the UK likely puts in enough security to counter, so you will need several methods to have a major impact, and I don't see what the extra methods would be.
 

Cook

Banned
Alexandrian/Scappa Flow raiders. Small submersible craft attacking major fleet units at anchor - because smaller is better when trying to penatrate the anti-submarine defenses...
By this, do you mean something other than the highly successful Italian manned torpedoes that carried out the raid on Alexandria?
 
Look at Italy in WW2. They used an old rusty freighter that was run aground in Spain to attack Gibraltar. At night, divers left a small hidden door at the water line and attached mines to UK shipping. The mines were set to go off after the ships had traveled 10's of miles, so the UK just thought it was mines floating in the Straights.
I forgot about that one. Wasn't there some problem with the current in the straights for the divers to swim through or something?


I am not sure spraying torpedoes helps. You want to get close and fire a good aimed shot, which a regular submarine does, fine.
6 X 48 = 288 per mothership's contingent. Have a 6 mothership wolfpack, and that becomes 1728 torpedoes running all over the place. Even the best aimed torpedoes will miss if the target(s) have a chance to take evasive action, but if the seas are filled with torpedoes (some of which are aimed right on) then there is a good chance that a ship that evades it's intended torpedoe might just blunder into another torpedoe's path.


Also another gimmick is just to preposition a freighter is some small anchorage somewhere that would be a mobile base for submarines. It is what I used in my TL for WW1. It has some limited potential without a permanent base, which my TL had ,but yours will not.
Dang it!
Now I will have to go and read your TL. Nooooo.......:D


You will find getting in torpedo range is more of an issue than the spread. Unless you have a Jutland like battle in WW2, and you will not, then mass attack does not mater much. You real issue will be bringing the capital ships to an area to attack. For example if you had U-boats that were faster than the Bismark, you could have them form a bubble around the Bismark, and make the UK life quite hard. The issue is you can't build a 35+ knot U-boat. You should probably focus on how to do a mass attack on something like Scapa Flow. I think you will find the Italian attack on Alexandria to be about the ideal method. The problem is that once used, the UK likely puts in enough security to counter, so you will need several methods to have a major impact, and I don't see what the extra methods would be.
What I have in mind is a ToT (Time on Target) assualt upon all the major fleet bases of both the UK and French navies. By whatever means needed.:eek:

As for the multiple submersible method, that is what I call the 'Convoy Crushers' for use against massed merchantmen out in the mid atlantic.
 
By this, do you mean something other than the highly successful Italian manned torpedoes that carried out the raid on Alexandria?
Yes and no. Were a pair of these divers not caught and taken down into the depths of the very ship they rigged? I don't have a problem with using divers to deliver the charges, but would want to have a means for them to exit the area if for no other reason than to avoid giving away the operation.
 

BlondieBC

Banned
I forgot about that one. Wasn't there some problem with the current in the straights for the divers to swim through or something?

The used a small device like you would find in a bond movie. Basically a submergable jet ski or manned torpedo, depending upon how you look at it.

6 X 48 = 288 per mothership's contingent. Have a 6 mothership wolfpack, and that becomes 1728 torpedoes running all over the place. Even the best aimed torpedoes will miss if the target(s) have a chance to take evasive action, but if the seas are filled with torpedoes (some of which are aimed right on) then there is a good chance that a ship that evades it's intended torpedoe might just blunder into another torpedoe's path.

There will be not reason to have that many UK ships in one location at any given time.

Dang it!
Now I will have to go and read your TL. Nooooo.......:D

You can basically read the first few years combined with the day in the life posts. But you can get to your concept. Imagine a freighter that is common looking loaded up with Japanese midget subs the Germans bought. It is in a remote Japanese port somewhere. When the war starts, it sails to near the main Indian Ocean UK base, and off loads 12-15 midget submarines, who then try to attack the harbor. I doubt it works that well based on Pearl Harbor attack, but with a little luck combines with some security issue at the UK base, it might sink a few capital ships. I don't see how the midget subs get away, so I guess you just scuttle them and have the navy guys surrender.

What I have in mind is a ToT (Time on Target) assualt upon all the major fleet bases of both the UK and French navies. By whatever means needed.:eek:

As for the multiple submersible method, that is what I call the 'Convoy Crushers' for use against massed merchantmen out in the mid atlantic.

I just don't see that working. These small subs will be too slow, too short ranged. The Oceans is a big place, hard to get your sub carrier near the convoy.
 
One idea I've considered and used on the old Red_Tide 1945 group was the use of WWII era subs as platform for luanching the tactical battle field rockets of the day. Rather than send a whole task force to hit a Japanese held island and its airfield one or two Gato class subs each with around 100 6" rockets being sent out on raids. When the raids are completed they proceed with a normal patrol. I really don't think the waterproofing issues would be that hard to deal with infact the whole rocket carrying assembly could be expendable
 

BlondieBC

Banned
One idea I've considered and used on the old Red_Tide 1945 group was the use of WWII era subs as platform for luanching the tactical battle field rockets of the day. Rather than send a whole task force to hit a Japanese held island and its airfield one or two Gato class subs each with around 100 6" rockets being sent out on raids. When the raids are completed they proceed with a normal patrol. I really don't think the waterproofing issues would be that hard to deal with infact the whole rocket carrying assembly could be expendable

The Germans experiment with a submerged towed rocket launcher that a U-boat sub towed. I don't see it really working well, but I could see the wonder weapon being used, and who knows, it might get lucky.
 
But, realistically, the manned torpedo was the best you could do at the time. And it was pretty effective, actually. You could try more, like at Gibraltar as well.

And, high speed in a sub was out at the time, unless you wanted a sub too small to carry actual people to know when to let go the mines. And, there's nothing you could do about the most effective ASW element, planes, other than the Luftwaffe, because they were more than 10x as fast.

And, like they said, aim is more important than saturation. A MG going full blast is, they, say, generally just a waste; and why would it be different in the water? And, the most effective weapon of today is the self aiming smart missile / bomb / torpedo. Aim is vital.

There was another even bigger RN fleet concentration, at Scapa Flow. But, it seems to've become practically unavailable to subs by the end of WW1. I don't think any U Boats killed anything there in WW2. That was partly shallow water, and partly netting and other obstacles that were easy to lay all around there.
 

BlondieBC

Banned
But, realistically, the manned torpedo was the best you could do at the time. And it was pretty effective, actually. You could try more, like at Gibraltar as well.

And, high speed in a sub was out at the time, unless you wanted a sub too small to carry actual people to know when to let go the mines. And, there's nothing you could do about the most effective ASW element, planes, other than the Luftwaffe, because they were more than 10x as fast.

And, like they said, aim is more important than saturation. A MG going full blast is, they, say, generally just a waste; and why would it be different in the water? And, the most effective weapon of today is the self aiming smart missile / bomb / torpedo. Aim is vital.

There was another even bigger RN fleet concentration, at Scapa Flow. But, it seems to've become practically unavailable to subs by the end of WW1. I don't think any U Boats killed anything there in WW2. That was partly shallow water, and partly netting and other obstacles that were easy to lay all around there.

No, one very daring captain got inside and sank at least one ship. If a full size U-boat could make it inside, a team of 10 of the Italian style micro-U-boats could make it inside. The trick is getting a mother ship close enough to Scapa Flow undetected, then it is just a larger version of the Alexanderia attack. Since it probably butterflies away the attack in the Med, it has a small impact in the war, but it could be an interesting TL to read. Maybe timed with the Norway operation, it could make a difference.
 
No, one very daring captain got inside and sank at least one ship. If a full size U-boat could make it inside, a team of 10 of the Italian style micro-U-boats could make it inside. The trick is getting a mother ship close enough to Scapa Flow undetected, then it is just a larger version of the Alexanderia attack. Since it probably butterflies away the attack in the Med, it has a small impact in the war, but it could be an interesting TL to read. Maybe timed with the Norway operation, it could make a difference.
Günther Prien with U-47, sinking the Royal Oak, an R class battleship.
 
Günther Prien with U-47, sinking the Royal Oak, an R class battleship.




Yes, this is the kind of thing I am wanting, but on a far larger scale. In my TL, the Germans will be looking for ways to 'even the odds' by unconventional thinking at the grand strategic level. This means building specialized forces to get the job done.

What if the U-47 had been one of a flotilla of submersible small craft designed and built to lay off Scappa flow (or any other RN naval base within their range), and been provisioned to await a proper time to launch a mass attack. IIRC, the U-47 feared to remain in the harbor for a prolonged time, and was thus forced to 'make due' with a single obsolete Battleship. OTOH, had a major contingent of the Home Fleet been present, and the attack carried out by a small craft flotilla....

For instance, your scouting the enemies fleet base's anti-submarine defences, and once you have found/made a way inside, you then mass your surface fleet for a breakout attempt, which causes the RN to mass for the block.....
 
A small sub will only have a limited air supply, surfacing is obviously out of question, and snorting, even at night, will be rather risky. So they won't be able to wait for too long.
 
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