Alternate German submarine developments.

Reply to @McPherson .
The current Japanese Soryou (sp?) Class has an aip range of 6100 nautical miles, according to Wiki. That's an ample sufficiency. Still modern, true, but they do have 8 in service.
 
Just how many miles submerged are we talking in a 1920's-1940's trans polar transit, anyway? I'm under the impression that the polar caps have shrunken much in the last century, but how much? Anyone got this information?
 
Reply to @McPherson .
The current Japanese Soryou (sp?) Class has an aip range of 6100 nautical miles, according to Wiki. That's an ample sufficiency. Still modern, true, but they do have 8 in service.

Book range is not endurance, nor is it hover time, power to run a navigation sonar system, or other necessary tools to navigate under ice. Remember that under the icepack you are limited to creep speed and you navigate solely by sound. Open ocean performance at creep speed is not a useful criterion that can be used because a sub can travel into a blind inverted canyon-like ice formation and has to be able to back itself out of such a trap. Atomics are the only current power train that allows this. Three weeks is a useful endurance estimate for a patrolling AIP capable boat that transits from say Halifax to Vancouver as start and endpoints. That seems to work (240 x 21 = 5,040) but that is not enough of a safety cushion to FIGHT under the arctic ice or even transit safely.

The USN has a lot of experience with the problem.
 
Just how many miles submerged are we talking in a 1920's-1940's trans polar transit, anyway? I'm under the impression that the polar caps have shrunken much in the last century, but how much? Anyone got this information?

For an atomic boat, about 4 days. (~120 hours). A long endurance fuel cell boat or other AIP boat? About 2x or 3x as long is very easy to estimate. They are of necessity because of their propulsion plants' limitations, much slower.
 
I think the greatest needs would be broken down into three important groups
a. Detection of potential targets across the ocean distances
b. Make an underwater sub
c. Stealth (U480) & Speed
d. Firepower
e. Production -- (structure the modular sub build)

a. LRMP patrollers. Have to get around Goring.
b. That is a given?
c. You cannot have both. Glue.
d. That is less important than weapons that work.
e. Kaiser is not in Germany.

1. Detection of enemy units -- ie sonobuoy, drone (perhaps short flight rocket with camera etc), German underwater sonar
2. Air Defense - Wasserfall
3. Sub to Ship guided weapon,
4. Anti sonar coating U480 : https://en.wikipedia.org/wiki/German_submarine_U-480
The U-boat was laid down in the Deutsche Werke in Kiel as yard number 311 on 8 August 1942, launched on 14 August 1943 and commissioned on 6 October 1943 under Oberleutnant zur See Hans-Joachim Förster. U-480 carried out three war patrols, all under Förster's command. Because of its coating, the boat was sent to the heavily defended English Channel. The Alberich worked; U-480 was never detected by sonar.
5. Streamlining - Like electroboat (for faster underwater speeds)
6. Battery increases in boat -- longer duration under water
7. Dutch Snorkel
8. Japanese Long lance Torp
9. German zig zag Torp

1. Has to await either better vacuum tubes (Americans will develop in 1943 and British will deploy sonobuoys.) Short flight rocket? Telemetry and launch problems. GsG already exists. Unless one means SOSUS and that requires 1950s signals processing at least.
2. Not possible.
3. Hunh? Wire guidance? Difficult.
4. See c. above.
5. Doable.
6. Doable.
7. See above about German troubles with induction valves. Their ingestor design was "problematic".
8. Japanese "oxygen boosted" torpedoes come with a host of problems (corrosion, leaks, explosive gas mixing, intensive maintenance.) that the Japanese learned to live with. Will the Germans do the same? Anyway, the Japanese were better craftsmen than either the Germans or the Americans when it came to torpedoes and they tested the things to an extent that neither the Germans or the Americans would be expected to do. So I do not see this happening.
9. FAT torpedoes are a given.
 
There are a number of WW2 weapon systems I am fascinated by. One such is the Italian Cagni-class submarine, a relatively conventional design, but with extreme range, a mind-numbing load of torps (albeit smallish and only suitable for escorts and civvy-type constructs), and two, count 'em, two, 100mm deck guns. Always wondered what a few dozen of those in German hands might have produced, specially operating from Dakar and Madagascar...
 
So, looking at the USS Nautilus' trans polar voyage, she was submerged for 1,590 miles, and did this in 96 hours. Averaging this to apx 16 kn submerged, we now have some concrete numbers to start with.

US submarine commanders are crazy, not insane, but definitely crazy. They do things that not even a Russian would contemplate.


And if one does not understand it, then one does not understand WHY the USS Nautilus' achievement is unique or how extraordinary it is. Anderson was running bat blind at 2/3 speed through uncharted and unknown hazard-infested shallow (in some places less than 100 meters vertical clearance from ocean floor to estimated ice shelf underside) with a submarine that was at least 1/5 that thick; sail to keel. Some of the ice was deeper than originally estimated. And you might be interested to know that Nautilus had to surface some times to take readings among the ice floes. So some of the bat blind run was at flank.
 
Regarding the Walter submarines, I Can see the Crew reluctance, bit actually quite a few were build. They were used quite extensively in trials. They didn’t blow up.
They were cancelled eventually because of nuclear submarines.
And as said before. Same Technology were used in torpedoes for decades more.
 
Gentlemen,

Some thoughts on WW2 U-Boat design and desired capabilities:

I'd hate to be in a U-boat under surface attack with no capable means of defense. A few vertical tubes and (acoustic) homing short range torpedoes. Primercord/rope with drag detonaters at each end (run into it and it could drape along the waterline, then Bang!

Another possibility would be an unpowered buoyancy glider. Here an unpowered buoyant homing attack device, fitted with small upsidedown wings could develop substantial speed over a horizontal distance equal to perhaps 12-15 times submerged release depth. If I recall correctly a group of Rutgers University / ONR experimenters paced such a device over a very long distance (transAtlantic?). Power was required only to alter buoyancy to permit the glider to climb and descend, moving forward all the while.

Possibly the technique described above could be employed to extend range under the Arctic ice cap if sufficient clearance is available between the bottom of the ice and the sea bed.

Depending on ice cap thickness (measured acoustically), shaped charge mines could open holes sufficient for a snorkel or the entire boat to surface and charge batteries.

More later, Dynasoar
 
The British experimented with HTP/Diesel fuel subs. The first was a recovered German boat renamed HMS Meteorite. In the mid fifties two smaller boats were converted to this propulsion. As I recall they were referred to as the "Blonde" class. The official names escape me, but to their crews they were the HMS Exploder and HMS Excruciating. Swear I remember a British movie about them with some Hollywood types.

Dynasoar
 
Regarding the Walter submarines, I Can see the Crew reluctance, bit actually quite a few were build. They were used quite extensively in trials. They didn’t blow up.
They were cancelled eventually because of nuclear submarines.
And as said before. Same Technology were used in torpedoes for decades more.

The British experimented with HTP/Diesel fuel subs. The first was a recovered German boat renamed HMS Meteorite. In the mid fifties two smaller boats were converted to this propulsion. As I recall they were referred to as the "Blonde" class. The official names escape me, but to their crews they were the HMS Exploder and HMS Excruciating. Swear I remember a British movie about them with some Hollywood types.

Dynasoar

The Germans had no success that was operationally credible.

HMS Excalibur and HMS Explorer; (HMS Excruciating and HMS Exploder). The "Blondes" derogation was in reference to hydrogen peroxide used in hair dyes that turned brunette hair blonde.
 
Gentlemen,

Some thoughts on WW2 U-Boat design and desired capabilities:

I'd hate to be in a U-boat under surface attack with no capable means of defense. A few vertical tubes and (acoustic) homing short range torpedoes. Primercord/rope with drag detonaters at each end (run into it and it could drape along the waterline, then Bang!

Drag lines and trackable objects pulled along the surface mean ASW mortars have visual cues at where to drop their charges. BOOM!

Another possibility would be an unpowered buoyancy glider. Here an unpowered buoyant homing attack device, fitted with small upsidedown wings could develop substantial speed over a horizontal distance equal to perhaps 12-15 times submerged release depth. If I recall correctly a group of Rutgers University / ONR experimenters paced such a device over a very long distance (transAtlantic?). Power was required only to alter buoyancy to permit the glider to climb and descend, moving forward all the while.

THIS is another visual cue and is actually used as an ASW weapon with mixed results. Fouling and own goal (BOOM!) hits on own forces has relegated the devices to moored mine cutters and snag drags in mine clearing operations.

Possibly the technique described above could be employed to extend range under the Arctic ice cap if sufficient clearance is available between the bottom of the ice and the sea bed.

No! Think about why this is a horrible idea? It is like locking oneself in a safe and playing cat fishing with a live grenade.

Depending on ice cap thickness (measured acoustically), shaped charge mines could open holes sufficient for a snorkel or the entire boat to surface and charge batteries.

More later, Dynasoar

Again... No! (Same safe, but this time, one hugs the live grenade.)
 
The Germans successfully launched rockets from the U-511 while submerged in 1942 but never followed up on it, the rockets were the same type used by the army and were plentiful. What if they had pursued this idea more fervently?
https://en.wikipedia.org/wiki/German_submarine_U-511

hfdYIUx.jpg
 
The Germans successfully launched rockets from the U-511 while submerged in 1942 but never followed up on it, the rockets were the same type used by the army and were plentiful. What if they had pursued this idea more fervently?
https://en.wikipedia.org/wiki/German_submarine_U-511

hfdYIUx.jpg

The U-boat in question.

US knowledge about the 30 cm (11.9 in) Nebelwerfer used in the test.

Summary, these are slow burn rate nitrocellulose solid fuel rockets. These can be insulated and adapted to launch at sea from a modified Nebelwerfer, bolted to the Type VII C (see illustration above). Therefore this is not a viable operational example of a useful missile firing submarine such as

tunnywregulas.jpg


this example. Note the rather bodged and extraordinary efforts that were needed to turn a Balao (GUPPY included) into a barely viable cruise missile launching submarine?
 
A very little digging makes me believe that not only would a trans-polar submarine route be possible, but surely successful if it was properly funded, the only question now is how much would it cost in time, money, and lives to achieve? In the OP I laid out that we need not be limited in our thinking to conform to a Nazi-German effort, that couldn't really even be properly started until herr Hitler gains the power to do this. I also said that we would be needing separate threads for some of the more specialized discussions/ideas, and I think that we are fast approaching that point now.

I'm seeing many thoughts being aired, for and against, the concept of submarine passage beneath the north polar cap, and the hidden link puts paid to the idea that it couldn't be done.

I'm also looking for original ideas for alternative weapons and equipment, and some have been posted upthread. Hoping to get this thread going good sometime this week...
 
The U-boat in question.

US knowledge about the 30 cm (11.9 in) Nebelwerfer used in the test.

Summary, these are slow burn rate nitrocellulose solid fuel rockets. These can be insulated and adapted to launch at sea from a modified Nebelwerfer, bolted to the Type VII C (see illustration above). Therefore this is not a viable operational example of a useful missile firing submarine such as

tunnywregulas.jpg


this example. Note the rather bodged and extraordinary efforts that were needed to turn a Balao (GUPPY included) into a barely viable cruise missile launching submarine?
I think with a little work they would've been useful for launching hit and run raids on coastal targets but only for a limited time, once the element of surprise was expended and the enemy came up with counter measures they would be vulnerable but for a short time, coastal cities would be vulnerable.
Would've been a nasty surprise for US cities on the eastern coast.
 
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