What was the maximum launch depth in wwii era subs?

[EmotionallyBroken]

steamdemandsspamtopost

[athenian]

What is a launch depth?

[Grumpy Old Dude]

he's asking for the max depth at which torpedoes could be reliably fired

[nihilcat]

In VIIC torpedoes were launched with the compressed air at 10,5 atmospheres. This means that the launch depth had to be considerably below 95 meters, to make it work, because the external water pressure reaches this value at that depth.

The second part is the inner tube door resistance, which was quite low from what I've read. I can't find the exact depth, but if I would have to guess... 30 meters or so would be the top depth they could risk, I think.

[EmotionallyBroken]

Originally posted by nihilcat:

In VIIC torpedoes were launched with the compressed air at 10,5 atmospheres. This means that the launch depth had to be considerably below 95 meters, to make it work, because the external water pressure reaches this value at that depth.

The second part is the inner tube door resistance, which was quite low from what I've read. I can't find the exact depth, but if I would have to guess... 30 meters or so would be the top depth they could risk, I think.

Thanks for such detailed on topic, and accurate information information nihilcat :)

Inner? You mean outter? I thought the sliding panels were just there for flow purposes and the loading hatch did all the pressure handling? (though I admit that is mostly speculation on my part because they slide I figure theyre not very "solid and water tight") Is it really the outter doors that did most of the pressure holding?


Reason Im asking is I remember launching torpedos down at 50 meters in silent hunter, where its much safer, and wondering why this game basically has you do it at the surface, and "Whats even realistic for a limit?"

*****************************************************************************
.Maybe we could put in "realistic consequences" for pushing the limit like springing leaks, :) What do you think of that idea? :)

[wolf310ii]

Originally posted by EmotionallyBroken:

Inner? You mean outter? I thought the sliding panels were just there for flow purposes and the loading hatch did all the pressure handling?

The outer torpedo tube doors are not the sliding panels, the sliding panels arent even water tight and without the outer doors, reloading the tubes would be impossible.

[nihilcat]

Originally posted by EmotionallyBroken:

Thanks for such detailed on topic, and accurate information information nihilcat :)

Inner? You mean outter? I thought the sliding panels were just there for flow purposes and the loading hatch did all the pressure handling? (though I admit that is mostly speculation on my part because they slide I figure theyre not very "solid and water tight") Is it really the outter doors that did most of the pressure holding?

No, I meant the inner doors, it wasn't a mistake 😉 The inner doors were exposed to external pressure immediately after launching a torpedo.

The outer doors were exposed to it all the time, but they were much more resistant, as they were opening outside. As wolf310ii pointed out, the outer torpedo doors are behind the sliding panels and normally are not visible.

Originally posted by EmotionallyBroken:

Reason Im asking is I remember launching torpedos down at 50 meters in silent hunter, where its much safer, and wondering why this game basically has you do it at the surface, and "Whats even realistic for a limit?"

I think there were reworked launchers on Type XXI that allowed for launching torpedoes from a much higher depth, but I haven't researched yet how it worked.

I also have to admit that the 30 meters estimation that I posted for VIIC is mostly a guess, although somewhat educated one as other, similar pressure-proof hatches had such design pressure according to VIIC manual. If there would be someone having raw numbers or examples from historical sources that would tell a different story, we may rework it appropriately sometime in the future.

[El Rushbo]

I read that they could fire as deep as 50m. However, a larger amount of compressed air would be required, plus at that depth you would have no periscope to rely on for targeting.

[[STW] cavour]

For U-Boot Type XXI, if I'm not wrong, maximum depth for launching torpedoes is about 45 meters, using sonar guidance only (obviously); that's what we can read from Dr. Eberhard Rössler's books

[THADDEUS MAXIMUS IV]

yes, GRAND ADMIRAL and FUHRER KARL DOENITZ said in his Memoirs that the XXI could fire twice as deep as the Type VII that they were to replace.......and I heard Israel's Diesel Coastal Subs were almost the same as the Type XXIII or whatever the WALTHER Sub was

[EmotionallyBroken]

Originally posted by El Rushbo:

I read that they could fire as deep as 50m. However, a larger amount of compressed air would be required, plus at that depth you would have no periscope to rely on for targeting.

I dont see why any compressed air is needed at all, the torpedos have their own propulsion.
I think I remember doing it around 50 meters in SH (Was that the limit there? its been some years)

Originally posted by nihilcat:

Originally posted by EmotionallyBroken:

Thanks for such detailed on topic, and accurate information information nihilcat :)

Inner? You mean outter? I thought the sliding panels were just there for flow purposes and the loading hatch did all the pressure handling? (though I admit that is mostly speculation on my part because they slide I figure theyre not very "solid and water tight") Is it really the outter doors that did most of the pressure holding?

No, I meant the inner doors, it wasn't a mistake 😉 The inner doors were exposed to external pressure immediately after launching a torpedo.

The outer doors were exposed to it all the time, but they were much more resistant, as they were opening outside. As wolf310ii pointed out, the outer torpedo doors are behind the sliding panels and normally are not visible.

Originally posted by EmotionallyBroken:

Reason Im asking is I remember launching torpedos down at 50 meters in silent hunter, where its much safer, and wondering why this game basically has you do it at the surface, and "Whats even realistic for a limit?"

I think there were reworked launchers on Type XXI that allowed for launching torpedoes from a much higher depth, but I haven't researched yet how it worked.

I also have to admit that the 30 meters estimation that I posted for VIIC is mostly a guess, although somewhat educated one as other, similar pressure-proof hatches had such design pressure according to VIIC manual. If there would be someone having raw numbers or examples from historical sources that would tell a different story, we may rework it appropriately sometime in the future.

Thanks for a beautifully detailed, thorough, honest, and humble input of information as well as having an open mind to improving based on such information. If only politicians were all this way, imagine how much fairer things would be :)



It sounds like there's an inner hatch door, and outer hatch door, and then sliding panels outside that? (I suppose I should look at some diagrams sometime,haha)

The inner doorss had a pressure limt estimated to be around 30 m, or as Rushbo has recalled reading , they could be fired as deep as 50 meters. This being withthe outer door(And panels) open, and the inner door closed to keep things at a more pleasant dryness level :)

Cavour mentions Eberhard Rosslers books statingthe 21 could launch at 45,......

New to me. Is that a historical author, fiction writer, biographer?

Seems like word on the street (at least here) is 45 m, at least for the later subs.

[wolf310ii]

Originally posted by EmotionallyBroken:

I dont see why any compressed air is needed at all, the torpedos have their own propulsion.

The torpedo tube are too thight for that.
Today there are submarines that can do that, but they have much wider torpedo tubes, with rails to keep the torpedo centered in the tube, so the water can flow around the torpedo and it can leave the tube under own propulsion.

Cavour mentions Eberhard Rosslers books statingthe 21 could launch at 45,......

New to me. Is that a historical author, fiction writer, biographer?

Its Rössler (or Roessler if you dont have a ö), he wrote technical books about u-boats and books for modell making (from the original to the modell)

[[STW] cavour]

Originally posted by wolf310ii:

Originally posted by EmotionallyBroken:

I dont see why any compressed air is needed at all, the torpedos have their own propulsion.

The torpedo tube are too thight for that.
Today there are submarines that can do that, but they have much wider torpedo tubes, with rails to keep the torpedo centered in the tube, so the water can flow around the torpedo and it can leave the tube under own propulsion.

Cavour mentions Eberhard Rosslers books statingthe 21 could launch at 45,......

New to me. Is that a historical author, fiction writer, biographer?

Its Rössler (or Roessler if you dont have a ö), he wrote technical books about u-boats and books for modell making (from the original to the modell)

Originally posted by STW cavour:

For U-Boot Type XXI, if I'm not wrong, maximum depth for launching torpedoes is about 45 meters, using sonar guidance only (obviously); that's what we can read from Dr. Eberhard Rössler's books

However, Dr. Eberhard Rössler is the leading expert on German submarines and underwater technology; he is the author of many technical and historical books on the subject
​

[FirestormMk3]

Originally posted by wolf310ii:

Originally posted by EmotionallyBroken:

I dont see why any compressed air is needed at all, the torpedos have their own propulsion.

The torpedo tube are too thight for that.
Today there are submarines that can do that, but they have much wider torpedo tubes, with rails to keep the torpedo centered in the tube, so the water can flow around the torpedo and it can leave the tube under own propulsion.

All accurate. Just to elaborate, torpedoes that use their own propulsion to launch are swim-out torpedoes, and a lot of the early examples that pop up after WWII were also early electric anti-submarine torpedoes. The early ones from the USN tended to be pretty slow and you had to slow to like 5kts to launch them. This was important for sub-to-sub torpedoes because you need *a lot* of compressed air to launch when running deep due to the pressure, plus they are much noisier when launched that way.

Swim-out torpedoes are really a creation of the Cold War, much like dedicated submarines. In the first two world wars submarines were really more torpedo boats that could briefly submerge, where the Cold War saw submarines with underwater endurance limited only by crew supplies and maintenance, and subs that were actually faster and more stable fully submerged than surfaced. True submarines rather than submersible boats. Torpedoes would also be shared back then - you'd find the same steam-powered torpedoes on a uboat as on a kriegsmarine destroyer, which would of course use a compressed air launcher to fire the torpedo off of a deck-mounted launch system into the water.

It's also worth remembering that torpedoes were not the only things a Type VII would be launching from its tubes, and things like mines definitely do not have their own propulsion.

You have to remember that proper submarine warfare was still in its infancy, and in many ways so was the supporting tech.

[EmotionallyBroken]

Originally posted by FirestormMk3:

Originally posted by wolf310ii:

The torpedo tube are too thight for that.
Today there are submarines that can do that, but they have much wider torpedo tubes, with rails to keep the torpedo centered in the tube, so the water can flow around the torpedo and it can leave the tube under own propulsion.

All accurate. Just to elaborate, torpedoes that use their own propulsion to launch are swim-out torpedoes, and a lot of the early examples that pop up after WWII were also early electric anti-submarine torpedoes. The early ones from the USN tended to be pretty slow and you had to slow to like 5kts to launch them. This was important for sub-to-sub torpedoes because you need *a lot* of compressed air to launch when running deep due to the pressure, plus they are much noisier when launched that way.

Swim-out torpedoes are really a creation of the Cold War, much like dedicated submarines. In the first two world wars submarines were really more torpedo boats that could briefly submerge, where the Cold War saw submarines with underwater endurance limited only by crew supplies and maintenance, and subs that were actually faster and more stable fully submerged than surfaced. True submarines rather than submersible boats. Torpedoes would also be shared back then - you'd find the same steam-powered torpedoes on a uboat as on a kriegsmarine destroyer, which would of course use a compressed air launcher to fire the torpedo off of a deck-mounted launch system into the water.

It's also worth remembering that torpedoes were not the only things a Type VII would be launching from its tubes, and things like mines definitely do not have their own propulsion.

You have to remember that proper submarine warfare was still in its infancy, and in many ways so was the supporting tech.

Thanks for clarifying how things worked out historically and how things were for the situations in game that are meant to be simulated