The XXI was not the fastest sub during WWII!

[USS Drum]

http://en.wikipedia.org/wiki/I-201_class_submarine

[iambecomelife]

4 torpedo tubes and 10 torpedoes is a very impressive armament for such a fast submarine. Also impressive that they managed to complete it long before the Type XXI and Type XXIII subs were built in Germany.
If the Japanese had gotten their act together and conducted a full-blown submarine campaign against shipping in the Pacific, WWII would have been quite different.

[USS Drum]

If only the Japanese had a better sub campaign although I know one sub with a spread of six torpedoes sank the carrier Wasp sank a destroyer and damaged the North Carolina.

[Hinrich Schwab]

Some of the submarine tech the IJN had was pretty amazing and contained the potential to change the war. Unfortunately for those elements of the IJN who wanted to focus on submarines, the IJN had its hands full with its Pro-Carrier and Pro-Battleship elements as well as being at constant loggerheads with the IJA. The sheer variety in Japanese submarines is respectable, including a submersible seaplane carrier, the I-400. Also, their torpedoes were much more reliable than either the German or the deeply flawed American torpedoes.

If Japan had adopted a similar attitude towards subs as Germany and America and followed through, it would have been very bad for the United States.

[USS Drum]

They also had a few other variants that could carry planes.

[CCIP]

Another important thing about the Japanese is that they had the best torpedoes of the war, hands down. They were many years ahead of both the Allies and the Germans in that, and had a weapon on their hands that was far more effective than anything else fielded throughout the war. The Long Lance and its derivatives were faster, longer-ranged, stealthier and more reliable than what the anybody else had to offer, even at the end of the war - main drawback being its complexity of course. And they had it from the start. It's a good thing for us, I guess, that the Japanese doctrine prevented it from being used to its true potential.

Originally Posted by iambecomelife

4 torpedo tubes and 10 torpedoes is a very impressive armament for such a fast submarine. Also impressive that they managed to complete it long before the Type XXI and Type XXIII subs were built in Germany.
If the Japanese had gotten their act together and conducted a full-blown submarine campaign against shipping in the Pacific, WWII would have been quite different.

Not quite so. By Feb 1945 over 100 advanced Type XXI were commissioned, training or running trials. The Japanese completed two. Although only one Type XXI, U-2511 actually conducted a war patrol, none of the advanced Japanese subs managed to do so.

Besides 14 torpedoes was the capacity of the Type VII and generally analysed as being woefully inadequate for commerce warfare. Fleet boats carried 24 and Type XXI, 23. Nothing to see here.

Japan was cursed by geography, there were no American strategic maritime choke points for merchant shipping that could not be dominated by US air power. Therefore the IJN would have had all of the operational problems faced by the U-Boats exacerbated by much greater distances, a lack of doctrine and training coupled with submarines ill-suited to commerce warfare. There was never any real prospect of an effective Japanese tonnage war.

Cdr Paul Schratz, USN in his book Submarine Commander devotes an entire chapter to the I-201 class, he commanded one of the two captured boats on a one-way trip to Pearl Harbor where it was studied and then expended as a target. Having first hand experience with the class, his impressions are far less gushing and awe-struck than those here.

The Long Lance was a 24" surfaced launched torpedo, they were not used in submarines. The submarine Type 95 was O2 powered like the Long Lance but packed far less punch due to its smaller diameter (21"). The single salvo from I-19 that sank Wasp, O'Brian and damaged North Carolina was undoubtedly the most damaging single torpedo salvo of all time.

However since neither O'Brian or North Carolina were actually intended targets, it says more about sheer luck than any inherent Japanese weapon, fire control or training superiority.

One thing about the Internet is that people tend to go gaga over military technology for its own sake without ever considering the economic, operational, doctrinal, logistical and even cultural aspects of introducing that technology into service.

[CCIP]

Yeah, and I think there's no better reminder of the impossibility of a Japanese submarine campaign than the fate of the far better-positioned German one.

By the same token, speed, performance or armament actually don't mean a thing. That's a common mistake made by sensationalist history. That's why something like the Yamato looks impressive in numbers, but was a stunning waste of resources in reality. Subs of all nations in WWII all had their own pluses and minuses, and in the end none of them was a perfect weapon. In fact if anything, WWII proved that the submarine as it existed up to then was doomed when faced with determined ASW. It took some time to reinvent the sub for the modern world, and the XXI or I-201 were just baby steps in getting there.

[vanjast]

If the IJN had a determined sub campaign.. they would caused crippling losses to the pacific task forces and invasion forces.
the wouldn't have to build their own subs, just buy them from the germans.

All they had to do is wait a few miles out from important target islands for the US fleet. This would have a heavy impact on Nimitz's and others campaign plans if not crippling it all together.

US ASW probably would have been ineffective as the subs would only be operation a few miles from their own home bases, well within their own ASW/patrol umbrella.

Sensationalist history is a good term but I think that ignorance history is more accurate. People merely parrot what they read or worse, see on TV. There is no attempt at critical analysis, no examination of cause and effect and no attempt to place the technology into context.

An example argument goes something like this:

If Hitler had not delayed the ME-262 in 1943, Germany would have won the War!

This ignores a number of inconvenient factors for the Jet Fighter Fanboy Club:

- Switching to jets would have had a major impact on the production of single-seat fighters needed for the defence of the Reich just as the Allied strategic bombing offensive was getting into stride;

- The year's production delay allowed continual improvement of the engines. In 1943 the service life of the 262's engines was essentially one sortie. By 1944 this had improved to over 12-hours. It also allowed the design to mature somewhat, improving the aerodynamics and structural strength of the airframe.

- Engine production in 1943 could not match even the very modest production of airframes, a problem greatly exacerbated by the short service life and one that was never solved.

- Training of the pilots would have been a formidable drain on resources, by all accounts the ME-262 was difficult to fly and easy to damage through mis-handling. It generally took 3-6 months to properly train a pilot on a completely new type and the 262 experience was like no other aircraft on earth.

- Once the pilots were trained, new combat techniques needed to be created, tested, adapted and incorporated into Luftwaffe doctrine. These sorts of thing take time to do correctly and getting it wrong tends to nullify any technological advantage provided by your "super weapon".

All of the above without even any considerations the unique airfield and maintenance requirements of the 262 that needed to be in place before the aircraft could be operational.

None of these things matter to the parrot lobby, only that the ME-262 had better numbers than anything the Allies had, Hitler was in idiot for delaying production and doing so cost the Nazi's their victory. It has to be true, "they" said so on the History Channel.

Originally Posted by vanjast

If the IJN had a determined sub campaign.. they would caused crippling losses to the pacific task forces and invasion forces.
the wouldn't have to build their own subs, just buy them from the germans.

All they had to do is wait a few miles out from important target islands for the US fleet. This would have a heavy impact on Nimitz's and others campaign plans if not crippling it all together.

US ASW probably would have been ineffective as the subs would only be operation a few miles from their own home bases, well within their own ASW/patrol umbrella.

Nope. The realities of WW2 submarine warfare or why the U-Boat campaign failed while the American submarine war was a success indicate an entirely different conclusion.

They attempted exactly what you suggest and failed totally, losing more boats than targets sunk to radar equipped aircraft, radio location and submarine ambushes. Acting as mobile minefields in defence of every potential island target would have been a desperate strategy, doomed to failure as finite resources required for other vital missions would have necessary and have drawn off the defensive boats. Once the US CVBG's sat over the horizon, there was no more Japanese air cover and the boats would have died, tied to a location they could not possibly defend against an alert, superior ASW force.

The Japanese faced far more formidable problems than the U-Boats, the distances were vast, the air threat unbeatable and they had lost the technology war before firing a shot. Not even their uber-torpedoes could save the day.

[Jimbuna]

Originally Posted by Randomizer

Not quite so. By Feb 1945 over 100 advanced Type XXI were commissioned, training or running trials. The Japanese completed two. Although only one Type XXI, U-2511 actually conducted a war patrol, none of the advanced Japanese subs managed to do so.

Besides 14 torpedoes was the capacity of the Type VII and generally analysed as being woefully inadequate for commerce warfare. Fleet boats carried 24 and Type XXI, 23. Nothing to see here.

Japan was cursed by geography, there were no American strategic maritime choke points for merchant shipping that could not be dominated by US air power. Therefore the IJN would have had all of the operational problems faced by the U-Boats exacerbated by much greater distances, a lack of doctrine and training coupled with submarines ill-suited to commerce warfare. There was never any real prospect of an effective Japanese tonnage war.

Cdr Paul Schratz, USN in his book Submarine Commander devotes an entire chapter to the I-201 class, he commanded one of the two captured boats on a one-way trip to Pearl Harbor where it was studied and then expended as a target. Having first hand experience with the class, his impressions are far less gushing and awe-struck than those here.

The Long Lance was a 24" surfaced launched torpedo, they were not used in submarines. The submarine Type 95 was O2 powered like the Long Lance but packed far less punch due to its smaller diameter (21"). The single salvo from I-19 that sank Wasp, O'Brian and damaged North Carolina was undoubtedly the most damaging single torpedo salvo of all time.

However since neither O'Brian or North Carolina were actually intended targets, it says more about sheer luck than any inherent Japanese weapon, fire control or training superiority.

One thing about the Internet is that people tend to go gaga over military technology for its own sake without ever considering the economic, operational, doctrinal, logistical and even cultural aspects of introducing that technology into service.

^ IMHO a good and accurate post

[Kapt Z]

Originally Posted by Randomizer

Nope. The realities of WW2 submarine warfare or why the U-Boat campaign failed while the American submarine war was a success indicate an entirely different conclusion.

They attempted exactly what you suggest and failed totally, losing more boats than targets sunk to radar equipped aircraft, radio location and submarine ambushes. Acting as mobile minefields in defence of every potential island target would have been a desperate strategy, doomed to failure as finite resources required for other vital missions would have necessary and have drawn off the defensive boats. Once the US CVBG's sat over the horizon, there was no more Japanese air cover and the boats would have died, tied to a location they could not possibly defend against an alert, superior ASW force.

The Japanese faced far more formidable problems than the U-Boats, the distances were vast, the air threat unbeatable and they had lost the technology war before firing a shot. Not even their uber-torpedoes could save the day.

Agreed.

Sure a more aggressive IJN submarine campaign would have hurt the US effort and caused more losses, but like the kamikazes, it would not have changed the final outcome- crushing defeat.

Besides, as Yamamoto knew in 1941. There was no way that Japan could compete with the US once the American industrial base got rolling.

[Hitman]

Of course it wasn't the fastest ... look at my signature

http://en.wikipedia.org/wiki/German_Type_XVII_submarine

[mookiemookie]

Originally Posted by vanjast

If the IJN had a determined sub campaign.. they would caused crippling losses to the pacific task forces and invasion forces.
the wouldn't have to build their own subs, just buy them from the germans.

How would this have worked when German submarine production couldn't even replace their own losses in the Atlantic? How would the subs have been delivered? The only way to get them there would have been sailing them to Japan around Africa. Logistically, the idea would never have worked.