Did Gemans invent...

Originally Posted by CCIP

It's also worth mentioning that hydrophones were never a primary detection method for submarines in WWII. Everybody at the start of WWII relied on submarines to hunt down their prey by first spotting it on the surface, either by periscope or by lookouts on the bridge. This was especially true of the Germans, and all their successful tactics (most notably the wolfpack) relied on submarines being able to keep visual contact with their prey, without diving.

With all respect I don't think that is entirely accurate since as I understand it, American pre-war submarine doctrine included provisions for submerged detection, approach and attack by passive sonar alone with active sonar just used for getting the final bearing and firing range.

The problem was that without the computer support for solving the target motion analysis problems that were developed post-war, the technique was theoretically sound but practically useless. As far as I know not one submerged sonar attack was successful, at least in the Pacific.

[CCIP]

Originally Posted by Randomizer

With all respect I don't think that is entirely accurate since as I understand it, American pre-war submarine doctrine included provisions for submerged detection, approach and attack by passive sonar alone with active sonar just used for getting the final bearing and firing range.

The problem was that without the computer support for solving the target motion analysis problems that were developed post-war, the technique was theoretically sound but practically useless. As far as I know not one submerged sonar attack was successful, at least in the Pacific.

Ah yeah, fair enough, I had heard of that, although this is why I also point out "successful german tactics" in the same paragraph later. I'm definitely talking about practice more than theory - a tactic in the books doesn't mean a successful tactic. I don't doubt that theories about making submerged-only approaches have been floating around since sonar was first invented, and might have even been in doctrine and on the books. However like you say, without more sophisticated TMA among other things, these were not a practical success.

I'm sure many a useful contact was picked up by hydrophone first, too. But all in all, I think all successful uses of WWII-era large submarines capitalized on them being able to survey the surface by eyeball or radar. As soon as they were unable to do that (like u-boats were unable to do once the Allied radar got sophisticated and widespread enough), these submarines became instantly obsolete along with their whole doctrine. Attempts to work around that with things like snorkels were marginally successful at best.

Originally Posted by CCIP

...this is why I also point out "successful german tactics" in the same paragraph later. I'm definitely talking about practice more than theory - a tactic in the books doesn't mean a successful tactic. I don't doubt that theories about making submerged-only approaches have been floating around since sonar was first invented, and might have even been in doctrine and on the books. However like you say, without more sophisticated TMA among other things, these were not a practical success.

This is very true and one should never forget that military theory all too often fails when confronted by military fact. According to RN pre-war ASW theory, ASDIC rendered the submarine essentially harmless. How did that prediction turn out for them?

[NightCrawler]

So, that's means that German U-boots are far advantage than the American submarine i mean in 1939?

I think Germans was pretty advantage not only in U boots, but also in planes, machine guns, tanks.

Even if you want to compare with VII class and Gato or Class SS33...

I think VII class u boots are tights, compare with the Gato class, nice and spacey...

please correct me if I'm wrong.

[Yoriyn]

You right.

But pacific war do not force americans to build smaller submarines. The bigger distances between the patrol-home and weaker japanese ASW tactic give them bigger construction tolerance ratio.

From the other hand WWII is a example when quantity is more important then quality.

Originally Posted by NightCrawler

So, that's means that German U-boots are far advantage than the American submarine i mean in 1939?

I think Germans was pretty advantage not only in U boots, but also in planes, machine guns, tanks.

Even if you want to compare with VII class and Gato or Class SS33...

I think VII class u boots are tights, compare with the Gato class, nice and spacey...

please correct me if I'm wrong.

My take is that it is futile to compare the 1939 U-Boat waffe with the submarine force of the USN. There only similarities is that both used diesel-electric submersibles designed to perform certain duties.

The former was created specifically for war on commerce and in the North Atlantic. All equipment, doctrines and training focused on that operational goal. When war came, they were ready and subject to politically imposed restrictions that eventually fell away, were generally able to fight the war that they had prepared for. When the U-Boats had to act in conjunction with the surface forces as in Norway during 1940 and in support of the Bismarck sortie and with surface forces in the Arctic, they can be judged an epic failure as is only reasonable to expect.

The USN's submarine force was trained and equipped to act in concert with the Battle Force's aim of fighting and winning a decisive battle using battleships supported by aircraft carriers. Their role was scouting and their targets exclusively enemy warships. Hence the large long-ranged, fast and well armed Fleet Boat had evolved to fill this particular tactical niche. America had totally rejected commerce war using submarines, the U-Boat campaign in 1917 had brought the USA into WW1 and in 1939 acting in a like manner was unthinkable. Pearl Harbor changed all that and over night the US submarine arm had to switch gears and fight the kind of war that was unanticipated and for which they lacked even basic doctrinal and training preparation.

It says a great deal for the overall flexibility of the USN that they were able to become as effective as they were, despite huge and painful errors of which the 1941-43 MkXIV torpedo crisis was only one. The Fleet Boats proved to be superb commerce destroyers in the vastness of the Pacific. Had the USN gone the route of the KM pre-war (and there were some on the Navy General Board who advocated smaller submarines), the story of the only successful unrestricted submarine campaign may have been written differently.

Many people around here like to compare the Type VII with the Fleet Boats but they are similar only in that they represented what their respective navy's considered to be the ideal weapon for their specific tactical role. The only U-Boat that was similar in size and capabilities to the Fleet Boat was the Type IXD2 U-Cruiser and it was inferior in speed, torpedo armament and habitability.

As for pre-war aircraft, it is good to remember that with only a few exceptions, every USAAF aircraft was a pre-war design. Thunderbolt, Mustang, Hellcat, Avenger, Lightning, B17, B-29, B-24, B-25, B-26, Dauntless and others, all pre-war designs and all equal or superior to anything of pre-1941 design flown by the Luftwaffe.

Can already feel the flames approaching for posting this so it's on with the NOMEX and apologies for droning on...

[Yoriyn]

You not correct about this some of the aircraft. Maybe they pre-war designed but build later. First Mustang flight in Oct1940 but introduced 1942, lightning introduced in 1941. Same situation was in germany and other countries. FW190 pre-war design introduced in 1941, even jetengine Me262 disigned in april 1939 (still pre-war) introduced in 1942.

Originally Posted by Yoriyn

You not correct about this some of the aircraft. Maybe they pre-war designed but build later. First Mustang flight in Oct1940 but introduced 1942, lightning introduced in 1941. Same situation was in germany and other countries. FW190 pre-war design introduced in 1941, even jetengine Me262 disigned in april 1939 (still pre-war) introduced in 1942.

I said designed and meant designed. Virtually every belligerant fought primarily with weapons that were built or on the drawing boards before they entered the war. That many of these changed beyond recognition (the BF-109 being an good example) indicates a soundness of design that allowed later versions to incorporate wartime improvements. As for the ME-262 it was certainly a pre war design but you reject the P-38 Lightning and it was in squadron service fully two years before the Messerschmidt; You cannot have it both ways.

I never said there are not exceptions, there are always some and a number of them were significant.