Alternate German submarine developments.

*High Tea = early sonarbuoys for radionavigation
*FIDO (navy) = Mark 24 homing torpedo applying similar principles to track and kill enemy
 
So was Fido...most air attacks Vs subs was with 'sticks' of bombs and only useful against surfaced and the 40 seconds of diving....otherwise useless.

On the other hand an attacking ASW vessel could use Fido in conjunction with sonar to attack all subs ....provided the subs were only managing 3-7 knots. Using that as a guide line to catch 12 knot sub you need torpedo of 19-20 knots DASH speed.


type 21 might have been anticipated but don't expect any operational mk 34 before end of decade in peace time or the end of the war in real time.



no idea what that means?
Most air attacks is not all air attacks;
The following is from "US Navy Torpedoes" by Frederick J. Milford:

"340 [Fido] torpedoes [were] dropped in 264 attacks of which 204 were against submarines. In 142 attacks US aircraft sank 31 submarines and damaged 15; in 62 attacks against submarines other Allies, mainly British, sank six and damaged three. Most of these submarine sinkings were German U-boats in the Atlantic, but five Japanese submarines were sunk by Fidos, one, I-52, in the Atlantic and four in the Pacific. OEG Study No. 289, 12 August 1946, is the main source for this conclusion."
Fido was first used successfully by a British B-24 Liberator defending Convoy HX 237 on 12 May 1943, sinking U-456. This was followed by a USN PBY-5A from VP 84 which sank U-640 on 14 May 1943

There are no stats given for ship launched attacks; the device is described as an aircraft launched weapon; I've personally never head of a ship launch and that don't seem too smart to me, anyhow...
 
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Ian_W

Banned
Yet a sane risk taker would arm to defend themselves within treaty limitation. Britain and France could not afford to occupy the Ruhr all the time. This is why it was left demilitarized rather than occupied before. You don't want to build up your defence industries there anyway. Too close to East Anglia, let alone France.

I'd really like to know why the Royal Navy would care, given that a reoccupation of the Rhine leads to a new German government in short order.

If you want a quick British rearmament, build lots of submarines.
 

perfectgeneral

Donor
Monthly Donor
I'd really like to know why the Royal Navy would care, given that a reoccupation of the Rhine leads to a new German government in short order.

If you want a quick British rearmament, build lots of submarines.
Britain was rearming anyway. The point of the naval treaty with Hitler was to limit and steer German rearmament in ways that made the German fleet less of a threat. They had drawn the line OTL. Keep within that and they are not surprised/alarmed. Permission to build aircraft carriers was an invitation to waste resources. Sensible priorities within agreed limits shouldn't incur wroth, only disappointment.

These are lots of small submarine boats, within acceptable tonnage compared to RN submarines. Small boats don't have the range to threaten her empire. It is the type VII that will ring alarm bells.

If you are saying that Germany should, ideally reoccupy the Rhineland before building a fleet (even on a defensive posture) then I can "get on board" with that. Although I'm still sceptical that allied reoccupation was on the cards. Even if it happened in such circumstances, it need not be the political demise of this hypothetical German government.
 
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Ian_W

Banned
Britain was rearming anyway. The point of the naval treaty with Hitler was to limit and steer German rearmament in ways that made the German fleet less of a threat. They had drawn the line OTL. Keep within that and they are not surprised/alarmed. Permission to build aircraft carriers was an invitation to waste resources. Sensible priorities within agreed limits shouldn't incur wroth, only disappointment.

These are lots of small submarine boats, within acceptable tonnage compared to RN submarines. Small boats don't have the range to threaten her empire. It is the type VII that will ring alarm bells.

Go look at a map of Europe.

Germany has three potential enemies - France, Russia and Britain.

Two of them have land borders with Germany. One nearly got strangled by a blockade by German submarines in the last war.

A type IIB coastal boat has a range of 3100 nautical miles, which is easily enough to patrol the Irish Sea from Germany.

Again, the RN is very very sensitive to certain sorts of threats. They are the sort of threats that go on, or under, water.
 
So was Fido...most air attacks Vs subs was with 'sticks' of bombs and only useful against surfaced and the 40 seconds of diving....otherwise useless.

On the other hand an attacking ASW vessel could use Fido in conjunction with sonar to attack all subs ....provided the subs were only managing 3-7 knots. Using that as a guide line to catch 12 knot sub you need torpedo of 19-20 knots DASH speed.


type 21 might have been anticipated but don't expect any operational mk 34 before end of decade in peace time or the end of the war in real time.



no idea what that means?

Successful hammer and anvil tactics or Able baker hunts require sonar fences. High Tea (HT) was what the British called the "navigation" sonar buoys they employed that were American invented. ^^^^^^^^^^^^^^^. That was the point of the history lesson. How does one think the Americans knew where to drop FIDO on a submerged boat? Sometimes visual on surface, sometimes radar, sometimes escort pingers or sometimes sonobuoys. It was American ASW doctrine to drive the U-boat down underwater, force it on the battery to slow it, by using depth charges, strafing or bombs; then drop FIDOs (if available) to chase it, fore and aft lead and lag. FIDO was relatively silent. The U-boats thus never knew what killed them.
 
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perfectgeneral

Donor
Monthly Donor
Go look at a map of Europe.

Germany has three potential enemies - France, Russia and Britain.

Two of them have land borders with Germany. One nearly got strangled by a blockade by German submarines in the last war.

A type IIB coastal boat has a range of 3100 nautical miles, which is easily enough to patrol the Irish Sea from Germany.

Again, the RN is very very sensitive to certain sorts of threats. They are the sort of threats that go on, or under, water.
Well the type II clearly exceeds the requirement if the range is that high. A Baltic training submarine and coastal defence U-boat need not have such a threatening range and can concentrated more on speed and batteries. The type IIa was almost half that range (1,600 nm) and development need not have gone in that direction. Perhaps the range extension was kept secret on the type IIb? I don't know how much these boats were subject to inspection, but that does seem needlessly provocative.
 
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Successful hammer and anvil tactics or Able baker hunts require sonar fences. High Tea (HT) was what the British called the "navigation" sonar buoys they employed that were American invented. ^^^^^^^^^^^^^^^. That was the point of the history lesson. How does one think the Americans knew where to drop FIDO on a submerged boat? Sometimes visual on surface, sometimes radar, sometimes escort pingers or sometimes sonobuoys. It was American ASW doctrine to drive the U-boat down underwater, force it on the battery to slow it, by using depth charges, strafing or bombs; then drop FIDOs (if available) to chase it, fore and aft lead and lag. FIDO was relatively silent. The U-boats thus never knew what killed them.
WOW basic tactics , glad the Americans figured it out, - took them long enough.

Son-buoys were pretty useless and the number of U-Boats sunk by air was ehhhh 213 sunk by air + 36 sunk cooperating with ASW Vessels. So the FIDO accounted for maybe 15-17% of U-Boats sunk. Mostly by bombs and mostly when the subs were on surface or crash diving.

Sonobuoys & ASW torps were post war weapons.
 
WOW basic tactics , glad the Americans figured it out, - took them long enough.

Son-buoys were pretty useless and the number of U-Boats sunk by air was ehhhh 213 sunk by air + 36 sunk cooperating with ASW Vessels. So the FIDO accounted for maybe 15-17% of U-Boats sunk. Mostly by bombs and mostly when the subs were on surface or crash diving.

Sonobuoys & ASW torps were post war weapons.

FIDO could hunt German subs slowed to battery power. German subs could theoretically outrun the fat FIDO torpedoes when surfaced (if only to die by other means). German engineers might have progressed further via their partner programs in Finland, the Netherlands, and Italy et al (bring in Japan if able too...) with testing of individual achievements on different submarines for different countries. Bring them together as isolated single prototypes only on secure inland rivers/lakes for shaking out some of the bugs and transitioning from theoretical to practical. Build en masse only after the war starts. Ideally do so with a working oxygen-driven torpedo.
 
I'd really like to know why the Royal Navy would care, given that a reoccupation of the Rhine leads to a new German government in short order.

If you want a quick British rearmament, build lots of submarines.

If the argument is rearmament early to promote industrial expansion and development as well as project authority, there is a logic to perfectgeneral's argument. Czechloslovakia might not have fallen if the Germans were slightly less well armed than they were, even if their best tanks were already beginning to be obsolete.
 

Ian_W

Banned
Well the type II clearly exceeds the requirement if the range is that high. A Baltic training submarine and coastal defence U-boat need not have such a threatening range and can concentrated more on speed and batteries. The type IIa was almost half that range (1,600 nm) and development need not have gone in that direction. Perhaps the range extension was kept secret on the type IIb? I don't know how much these boats were subject to inspection, but that does seem needlessly provocative.

And you really expect the RN doesnt think the Germans are building a future model with extended range fuel tanks ?

Just how gullible do you think the RN is ?
 
WOW basic tactics , glad the Americans figured it out, - took them long enough.

Son-buoys were pretty useless and the number of U-Boats sunk by air was ehhhh 213 sunk by air + 36 sunk cooperating with ASW Vessels. So the FIDO accounted for maybe 15-17% of U-Boats sunk. Mostly by bombs and mostly when the subs were on surface or crash diving.

Sonobuoys & ASW torps were post war weapons.

HUSL (love puns) and before the British did. But for sonabuoys, one must look to Columbia University.

Some history.

As you can see....

Son-buoys were pretty useless

pps. 324-330 and specifically pps. 329-330 USS Bogue HK group.

The I-52 was just one example of USN sonobuoy use with FIDO. A classic HAMMER and ANVIL attack.

The sonobuoys were not useless.
 
And you really expect the RN doesnt think the Germans are building a future model with extended range fuel tanks ?

Just how gullible do you think the RN is ?

a quick glance (at 1940) shows the Italians, Japanese, and Soviets with 350 submarines and Germans with 50-odd more, considering the global responsibilities of the RN what difference would 25-odd MORE German submarines make? seriously, and not disputing your view of their diligence.

thought their primary aim (regarding Germany) was to end building of hybrid Panzerschiffe?
 
a quick glance (at 1940) shows the Italians, Japanese, and Soviets with 350 submarines and Germans with 50-odd more, considering the global responsibilities of the RN what difference would 25-odd MORE German submarines make? seriously, and not disputing your view of their diligence.

thought their primary aim (regarding Germany) was to end building of hybrid Panzerschiffe?

1. Japan and Italy are German "friends" and allies. Russia is geographically null at sea, and not a factor in RN planning.

2.
northsea.gif


3. Alfred Thayer Mahan.

In his memoirs, From Sail to Steam, Mahan credited his reading of Theodore Mommsen’s six-volume History of Rome for the insight that sea power was the key to global predominance. In The Influence of Sea Power Upon History, Mahan reviewed the role of sea power in the emergence and growth of the British Empire. In the book’s first chapter, he described the sea as a “great highway” and “wide common” with “well-worn trade routes” over which men pass in all directions. He identified several narrow passages or strategic “chokepoints,” the control of which contributed to Great Britain’s command of the seas. He famously listed six fundamental elements of sea power: geographical position, physical conformation, extent of territory, size of population, character of the people, and character of government. Based largely on those factors, Mahan envisioned the United States as the geopolitical successor to the British Empire.

Now, note who are at opposite ends of the North Sea? At one time it was the Vikings who were Britain's nemesis, then Spain and then France, and Holland and then France again, but in the 20th century, that nemesis was/were the nations who could put submarines to the immediate west of the British Isles. Germany first, and then after WW II when the Russians built their own submarine fleet, the Red Navy.

Better map.

800px-Ocean_dumping_of_radioactive_waste_in_Atlantic_Ocean.png


The Germans and the Russians have to get past Great Britain to use the Atlantic. The Russians were in a better position pre WW II but lacked the skills. The Germans, who had the skills, lacked the geography until they took Norway and France. However, the Germans could shoot Type II subs through the North and Norwegian Seas, passing the Shetlands, Faeroes, Iceland gap and operate off the Western Approaches and Irish Seas. This is not good.
 
1. Japan and Italy are German "friends" and allies. Russia is geographically null at sea, and not a factor in RN planning.

The Germans and the Russians have to get past Great Britain to use the Atlantic. The Russians were in a better position pre WW II but lacked the skills. The Germans, who had the skills, lacked the geography until they took Norway and France. However, the Germans could shoot Type II subs through the North and Norwegian Seas, passing the Shetlands, Faeroes, Iceland gap and operate off the Western Approaches and Irish Seas. This is not good.

got it! (hence my fixation on speculative German operations from Greenland)

was questioning the marginal numbers of German submarines, when they build any it is a BFD, if they look set to build only subs? super BFD, but what is the difference between 50, 60 , 70? as against the 400-odd subs from potential enemies they were already facing?

(of course this is a thread on submarine developments, my view they were deficient to greater degree in S-boats, numbers and development)
 
First, the British are not facing 400 subs from "enemies" at the start of WW II. They are facing ~ 25 U-boats deployable from Germany. Using the rule of thirds, where 1/3 are going to and from stations, 1/3 are on station and 1/3 are refitting, that actually means 8 or 9 U-boats patrolling. So 40 U-boats means 13-14 on station, 50 means about 16-17, 60 ='s 20 on station, 70 U-boats ='s 23-24 on patrol. At it's peak, the U-boat arm with ~ 350 boats operationally was never able to put more than ~ 120-160 at sea at maximum at any one time.

By contrast, the US subs, which have twice the ocean area to cover at max strength and only about 200 subs available at that peak strength in the Pacific; was able to station and patrol about 80 subs consistently during the halcyon years of *44 and *45.
 
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HUSL (love puns) and before the British did. But for sonabuoys, one must look to Columbia University.

Some history.

As you can see....



pps. 324-330 and specifically pps. 329-330 USS Bogue HK group.

The I-52 was just one example of USN sonobuoy use with FIDO. A classic HAMMER and ANVIL attack.

The sonobuoys were not useless.



They were pretty useless, since most subs were destroyed because they were spotted on the surface and attacked there after. When sonobuoys were used they were difficult in localizing target and any interception of target relied on lucky ASW TORPEDO, They are only comparable to early sonar if the target subs are recharging with diesels, The expected sweep rate is 15 nm^2 per hour compared to MAD which is 15-20nm^2 per hour. ASDIC were only marginally more effective @ 15nm ^2 per hour , however the difference is the ASDIC ship can search for days, while any ASW planes can't carry enough sonobuoys to cover more than a hour.

However the above sweep rates for MAD & SONOBUOYS are iffy at best anyway- since they are based on trials. As a rule combat results are 1/3 as effective as trails.

SEE PAGES 140-142

http://navgunschl2.sakura.ne.jp/tenji/oeg_asw/OEG_No51_E.pdf
 
The I-52 was not recharging with diesels. It was killed, along with 36 + Germans using the PIM target (PROJECTED INTENDED MOTION) tactics that caught it.

For if the base start position of a sub is known, sonobuoys can isolate the baseline course and put ASW forces into position to corral the submerged sub. That is the whole point of the cloverleaf drops which form the sonar fence.

Your 1946 citation is therefore somewhat misleading as to how sonobuoys are used and what the function of the things is supposed to be. Refer to the 2013 document for better information as to the actual tactical employment.
 
The I-52 was not recharging with diesels. It was killed, along with 36 + Germans using the PIM target (PROJECTED INTENDED MOTION) tactics that caught it.

For if the base start position of a sub is known, sonobuoys can isolate the baseline course and put ASW forces into position to corral the submerged sub. That is the whole point of the cloverleaf drops which form the sonar fence.

Your 1946 citation is therefore somewhat misleading as to how sonobuoys are used and what the function of the things is supposed to be. Refer to the 2013 document for better information as to the actual tactical employment.


The sample is too small to reliably predict anything. Its anecdotal at best.
 
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