Rn vs IJN (1 Viewer)

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Shortround6 said:
Many of the Japanese escorts or even fleet destroyers did not have radar in the early part of the Pacific war which was more than a bit late by European standards.

The Japanese asdic was several generations behind the British and the gap increased. It also did not not help that some of the late Japanese escorts were noisy.

About as advanced as the Japanese got for ahead throwing weapons was a single 80mm army mortar mounted ahead of the Bridge. This arrived late and obviously was not very effective.
While the British Hedgehog showed up in late 1942 poor training delayed it's use for quite a number of months. Crews did not have confidence in it's ablities or proper training in use. There as a lot more too it than point the ship at the suspected area and fire away.

However the Japanese never even got close even in 1945.

A lot of British or American hunter teams used one or more ships to 'fix' the subs (locate and track) and would then use the radio to coach the firing ship into position. The ships own asdic would not point down enough and the target would be lost on the attack runs. If the first run did not work they would often swap and one of the trackers would make an attack run while the first attacker reloaded it's launcher/s while providing asdic support for the new attack ship.

However this also needs practice, training and good voice radios. This was also going into 1944.

The Japanese in late 1941 were behind, well behind, where the RN was in late 1939 as far as ASW.

However in a somewhat similar historical pattern the numerous (by Japanese standards) escorts don't show up until 1944-45, leaving most of the early war work to be done by a few handfuls of converted destroyers, steam torpedo boats and patrol boats. And in 1942 few had radar, not all had Asdic, DC storage was small and so on.
Much of the ASW was done by fleet destroyers "on loan" in the first part of the war as they didn't have enough escort ships.
In April of 1942 the were only two escort groups (this is after all of the early conquests')
The 1st escort group had 10 old destroyers, two torpedo boats and 5 converted gun boats for the Japan to Singapore route.
The 2nd escort group had 4 old destroyers, two torpedo boats and 1 converted gun boat for the Japan to Truk route.

There were a few other odds and sods but obviously they needed fleet destroyers to fill in. And that leads to poor training or team work. The Japanese never had a ASW school. In fact some of their escort commanders (late in the war?) were from the merchant marine academy and not the Naval Academy and we can imagine how well that worked in mixed groups.
The RN was not perfect but the distinction between the regular navy and "wavy navy" was probably the least marked in any navy.
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That's all very interesting, considering the US lost 41 submarines in the Pacific Theater. Did they all sink themselves with defective torpedoes?
 
Wild_Bill_Kelso said:
That's all very interesting, considering the US lost 41 submarines in the Pacific Theater. Did they all sink themselves with defective torpedoes?
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Even a blind pig finds an acorn once in while?


Might help to actually compare the record.

Japan started the war with 64 boats and added 126 boats and lost 129 boats. 66.8% losses
US started the war with 112 boats and added 203 boats and lost 52 boats world wide. Only 28 of the new boats were lost. Overall loss rate 16.5%

It would seem that being an American submariner was much safer than being a Japanese submariner.
But that can't be right because the Japanese were technologically more advanced, right?
 
Shortround6 said:
Kind of gets us into another thread ;)

As we know the Japanese planned for two more Yamatos.
The Design work for the Iowa's was started in 1938 with rumors of Japanese 46,000 ton BBs.
4 were ordered before 1940.
In the massive naval bill of July 19th 1940 there were another two ordered and five Montana class (Twelve 16in guns) and they may have decided on the Twelve 16in gun option as taking less time than designing/developing/building the 18in gun option.

It would have been very messy but the Yamato's were never going to be facing US 16in BBs one to one. It was always going to be 2.5-4 to 1.
The US could afford to lose ships, the Japanese could not.
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But the problem with that formula, at least in the real world as distinct from planning, that the US (or say, UK) warships were highly vulnerable to torpedo attacks by not just the ostensible fleet subs, but smaller Japanese surface warships like DDs and CLs, and even CAs. Not to mention aircraft.
 
Shortround6 said:
It would seem that being an American submariner was much safer than being a Japanese submariner.
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We had cracked the IJN codes and the Japanese subs were careful to radio their positions and plans.
Were that not enough to reveal their movements, when they were moving out of a patrol area they liked to surface and shell whatever the could find to shoot at.
And, of course, RADAR.
Meanwhile, the Germans lost 500 plus boats.
 
Wild_Bill_Kelso said:
But the problem with that formula, at least in the real world as distinct from planning, that the US (or say, UK) warships were highly vulnerable to torpedo attacks by not just the ostensible fleet subs, but smaller Japanese surface warships like DDs and CLs, and even CAs. Not to mention aircraft.
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All warships were highly vulnerable to big explosey thingies. What's your point? All the big navies had some things that were better, sometimes substantially so, than the equivalent things in other navies. Like the Japanese Long Lance torpedoes, yes. But were they some kind of wunder weapon that would have decided a fleet battle? Most likely not.

In any case the point is moot, as the USN were never going to be suckered into some kind of Mahanian ultimate fleet battle early in the war where losing it might have forced them to the negotiation table. Strategically, they were happy to hold the line while the war industry at home went BRRRT.
 
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z42 said:
All warships were highly vulnerable to big explosey thingies. What's your point? All the big navies had some things that were better, sometimes substantially so, than the equivalent things in other navies. Like the Japanese Long Lance torpedoes, yes. But were they some kind of wunder weapon that would have decided a fleet battle? Most likely not.
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Well, the Japanese torpedo was considerably better than those of the Americans, of course, and also a good bit better (as in twice or three times) than the British torpedoes. And the neither the Americans nor the British were aware of it's true capabilities until quite late in the war.

This remarkable capability, and the lack of awareness of it's deadly range and speed by Anglo-American navies, contributes substantially to lopsided Japanese victories in several naval battles, both with the USN and RN, during the early part of the Pacific War.

z42 said:
In any case the point is moot, as the USN were never going to be sucked into some kind of Mahanian ultimate fleet battle early in the war where losing it might have forced them to the negotiation table. Strategically, they were happy to hold the line while the war industry at home went BRRRT.
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I don't posit any theoretical grand battle of entire fleets, but in many smaller scale but still telling surface and air to surface engagements, the Japanese type 91 and type 93 torpedoes won the day for the Japanese. In the real, historical IJN vs USN matchups, this made a difference, and certainly prolonged the war. In an ostensible RN vs. IJN war, as in the subject of this thread, I think it is likely that it would be telling. The Yamato class and other earlier IJN battleships would not be on their own, and the (literal and figurative) impact of their torpedoes would have helped even the balance between numbers of surface ships, or even help to tip them over the edge into victory.
 
3 times the range does not equal 3 times the effectiveness. Better yes.

I have posted diagrams of Japanese cruisers earlier. You usually cannot hit what you can't see, accidents do happen though, including own goals. Destroyers have lower bridges/fire control positions than cruisers with less visual range. Each ship needs to work out their own firing solution. No data sharing ;)

Japanese torpedoes were faster, faster gives shorter time to impact which is better, What is 20% worth? what is 15% worth and so on.

Torpedo warheads varied, a lot. Japanese torpedoes used heavy warheads, The Allies got better explosives later on, 1941-42 was pretty much TNT.

All Three navies used 3 different torpedoes (at a minimum).
All three used a different aerial torpedo than most surface ships/subs.
All three used different sub torpedoes than surface torpedoes.
and for torpedoes 4 and 5 (and 6/7) all three used different different sub and surface torpedoes depending on the age of the the ships.

For the US this meant that the S type subs used different torpedoes than the new boats (not problem free but fewer) and that the old 4 stack destroyers used different torpedoes than the newer destroyers. Granted a lot of the old stuff disappeared in the first 3-6 months of the Pacific war.

Trying to do long range torpedo shots on a 5-9 ship formation doing 24+ kts is different than trying to do long range shots at 15-20 ship formation (or 30 including destroyers?) doing 18kts. The old American battlefleet was NOT going to do 21 kts even in battle (actual shooting) do to slightly different speeds and turns/maneuvering needing a margin for formation keeping. Besides, 21kts was with clean bottoms.
 
Shortround6 said:
3 times the range does not equal 3 times the effectiveness. Better yes.

I have posted diagrams of Japanese cruisers earlier. You usually cannot hit what you can't see, accidents do happen though, including own goals. Destroyers have lower bridges/fire control positions than cruisers with less visual range. Each ship needs to work out their own firing solution. No data sharing ;)
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Japanese ships did have radios, and they did coordinate attacks. They also used seaplane scouts for targeting, including at night in some of the battles in the Solomons for example. My point is that Japanese light cruisers and destroyers were quite formidable weapons in the first two years or so of the war, and continued to be a threat almost to the end. Definitely a force multiplier for the heavier Japanese ships. They clearly outfought USN heavy cruisers in several engagements basically on their own, even though the latter considerably outgunned them.

Shortround6 said:
Japanese torpedoes were faster, faster gives shorter time to impact which is better, What is 20% worth? what is 15% worth and so on.
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Japanese torpedoes were either faster or much longer ranged. Depending on the setting. They were used both ways historically, often resulting in sunk enemy ships.

Shortround6 said:
Torpedo warheads varied, a lot. Japanese torpedoes used heavy warheads, The Allies got better explosives later on, 1941-42 was pretty much TNT.

All Three navies used 3 different torpedoes (at a minimum).
All three used a different aerial torpedo than most surface ships/subs.
All three used different sub torpedoes than surface torpedoes.
and for torpedoes 4 and 5 (and 6/7) all three used different different sub and surface torpedoes depending on the age of the the ships.
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My understanding is that all types of the Japanese torpedoes - air launched, surface launched, and submarine launched, were exceptionally good.

Shortround6 said:
For the US this meant that the S type subs used different torpedoes than the new boats (not problem free but fewer) and that the old 4 stack destroyers used different torpedoes than the newer destroyers. Granted a lot of the old stuff disappeared in the first 3-6 months of the Pacific war.
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Yes if I am understanding you correctly, the very early war US torpedoes (early 1942) worked better than what came after (mid 1942-late 1943)

Shortround6 said:
Trying to do long range torpedo shots on a 5-9 ship formation doing 24+ kts is different than trying to do long range shots at 15-20 ship formation (or 30 including destroyers?) doing 18kts. The old American battlefleet was NOT going to do 21 kts even in battle (actual shooting) do to slightly different speeds and turns/maneuvering needing a margin for formation keeping. Besides, 21kts was with clean bottoms.
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Well I'm not sure what is your point here but we know historically IJN surface ships very effectively launched spreads of torpedoes that wrought great havoc on Allied warships in the actual battles. We actually got lucky with the Washington. IJN submarines also sunk a few CVs as I remember...
 
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Wild_Bill_Kelso said:
Yes if I am understanding you correctly, the very early war US torpedoes (early 1942) worked better than what came after (mid 1942-late 1943)
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They crossed over. The S boats in the Philippines used the older torpedoes which had one common flaw with the MK 14s, not 3.
Sort of the same for the old destroyers, which used MK 11 (?) or mk 12 torpedoes instead of MK 15s. However the old torpedoed used rather light warheads.
Wild_Bill_Kelso said:
Well I'm not sure what is your point here but we know historically IJN surface ships very effectively launched spreads of torpedoes that wrought great havoc on Allied warships in the actual battles.
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The point is that the Japanese never used the type 93 in it's intended role of attritting the main US Battle fleet. Things had changed in the years between the adoption of the torpedo and actual war. Long range shots at a Jutland style/size fleet never happened, in part because of the Japanese success at Pearl Harbor. There was no US battle fleet of 10-12 BBs and associated CAs and Cls traveling together with DDs screening them. The Actual actions involved mush smaller numbers of ships which which means smaller target area which usually called for closer ranges. Yes the Japanese fired at longer ranges than the Allies did and took them by surprise but the over 30,000meter range may neve have been used in practice?
Wild_Bill_Kelso said:
My understanding is that all types of the Japanese torpedoes - air launched, surface launched, and submarine launched, were exceptionally good.
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They were all good but in different degrees.
Japanese 18in aerial torpedoes don't seem to have much advantage over British 18in Torpedoes for most of the war. Both types were modified several times during the war so let's make sure we are comparing the correct versions and not comparing 1944 specs for earlier battles, for both sides.
Wild_Bill_Kelso said:
Japanese ships did have radios, and they did coordinate attacks. They also used seaplane scouts for targeting, including at night in some of the battles in the Solomons for example
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two different types of coordination, having flotilla flagship signal "attack enemy at bearing 115" is not giving firing solutions. A destroyer 4 ships back from the flagship is going to have a range 2000-4000yds different and a slightly different bearing. Same for float plane/s. The firing ship/s need to work out the exact range and correct bearing for the torpedoes to run at to hit the target or target area when the torpedoes get there. No two ships will fire at the exact same bearing because of their own locations in the formation.
A simultaneous launch rarely happened, there were often ripple launches or launches in turn as the firing fleet turned away. A lot depends on the bearing the enemy is at and the maneuver (turn) needed to clear the tubes to launch.
Now find an account that ship XXX fired their torpedoes on bearing 115 without seeing an enemy ship because the Flotilla commander said "fire torpedoes on bearing 115!"

They didn't fire guns that way, they at least fired at gun flashes.
 
The Japanese Long Lance torpedoes not only had longer range and more of a punch than US torps, but also they were much more RELIABLE.

The US torps were built by the USN owned and operated Goat Island facility in Rhode Island, which proved to be the equivalent of having your local Dept of Motor Vehicles design and build your car. The US torps suffered from totally inadequate testing and reliance on a magnetic exploder designed to explode the warhead as the torp passed under the ship, theoretically enabling a single torp to sink a ship by breaking its back. But the magnetic exploder proved to be very unreliable due to varations in the Earth's magnetic field. Also, in order to save money so they could hire more govt civilian workers the contact detonater was not thoroughly tested and proved to be unreliable as well. And the Federal Civilian Workers used a craftsman approach rather than mass production methods in order to ensure they could not be fired. They were very proud of the fact that by really working hard they could produce as many as 50 torpedoes a month. The actual USN WW2 combat requirements proved to be 1500 torpedoes a month. To complaints of an inadequate supply of torps they responded that the incompetent sub skippers were wasting them.

And of course the command of the RI torpedo factory was a coveted assignment reserved for only the USN's top officers, those headed for flag rank - and once at the top they KNEW their fine torpedoes were superb.

Ironically the secret of the Long Lance was simply using O2 rather than air to supply the engine, and that was inspired when a IJN officer noted O2 equipment on board a RN ship, which led to the IJN assuming it was a good idea since the RN obviously was using it. But that was just test equipment for the RN, which had abandoned the idea before it went operational.

The sad story of the USN torps is well covered in "Silient Victory" by Clay Blair and "Hellions of the Deep" by Robert Gannon. They USN finally fixed the problems when they had a Harvard/GE team develop the acoustic homing torpedo and when that proved to be an outstanding success from the Gitgo gave them the job of fixing the existing torps. Meanwhiile, when the RI factory proved to be totally incompetent at duplicating captured German electric torps, they gave gave that job to Westinghouse.
 
MIflyer said:
The Japanese Long Lance torpedoes not only had longer range and more of a punch than US torps, but also they were much more RELIABLE.

The US torps were built by the USN owned and operated Goat Island facility in Rhode Island, which proved to be the equivalent of having your local Dept of Motor Vehicles design and build your car. The US torps suffered from totally inadequate testing and reliance on a magnetic exploder designed to explode the warhead as the torp passed under the ship, theoretically enabling a single torp to sink a ship by breaking its back. But the magnetic exploder proved to be very unreliable due to varations in the Earth's magnetic field. Also, in order to save money so they could hire more govt civilian workers the contact detonater was not thoroughly tested and proved to be unreliable as well. And the Federal Civilian Workers used a craftsman approach rather than mass production methods in order to ensure they could not be fired. They were very proud of the fact that by really working hard they could produce as many as 50 torpedoes a month. The actual USN WW2 combat requirements proved to be 1500 torpedoes a month. To complaints of an inadequate supply of torps they responded that the incompetent sub skippers were wasting them.

And of course the command of the RI torpedo factory was a coveted assignment reserved for only the USN's top officers, those headed for flag rank - and once at the top they KNEW their fine torpedoes were superb.

Ironically the secret of the Long Lance was simply using O2 rather than air to supply the engine, and that was inspired when a IJN officer noted O2 equipment on board a RN ship, which led to the IJN assuming it was a good idea since the RN obviously was using it. But that was just test equipment for the RN, which had abandoned the idea before it went operational.

The sad story of the USN torps is well covered in "Silient Victory" by Clay Blair and "Hellions of the Deep" by Robert Gannon. They USN finally fixed the problems when they had a Harvard/GE team develop the acoustic homing torpedo and when that proved to be an outstanding success from the Gitgo gave them the job of fixing the existing torps. Meanwhiile, when the RI factory proved to be totally incompetent at duplicating captured German electric torps, they gave gave that job to Westinghouse.
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Yes I think most people here are aware of this but it bears repeating.

The US mark 13, mark 14 and mark 15 also had a lot of other problems. In one test of the (air launched) Mark 13, 36% "ran cold", 20% just immediately sank, 18% ran too low in the water to hit a ship, and only 31% even finished their run at a depth that they could hit a target (which in combat then often failed due to the magnetic detonator you mentioned). The (submarine launched) mark 14 also often ran too deep, had major issues with the magnetic detonators, and had the additional nightmarish quality of running in a big circle and hitting the submarine that launched them (apparently the Grunion and Tullibee were sunk this way, and the Sargo was almost sunk. The replacement Mark 18 did the same thing and sank the Tang).

The (surface ship launched) Mark 15 had some kind of 'collar' which prevented the circular run at least, but had most of the same other problems of running too low, sinking, running on the surface, and failed magnetic detonator. One of the first effective uses of these during the war was at the Battle of Vella Gulf in August 1943, during which the commander of the US force personally made the (correct) decision to disable his magnetic detonators and adjust the running depth against regulations. Until that point, the Mark 15s were basically useless in combat, with very rare exceptions. They often even failed in scuttling attempts.
 
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Shortround6 said:
They crossed over. The S boats in the Philippines used the older torpedoes which had one common flaw with the MK 14s, not 3.
Sort of the same for the old destroyers, which used MK 11 (?) or mk 12 torpedoes instead of MK 15s. However the old torpedoed used rather light warheads.
Click to expand...

Better to hit with the light warheads than have it fail altogether, or circle back and hit the launching submarine.

Shortround6 said:
The point is that the Japanese never used the type 93 in it's intended role of attritting the main US Battle fleet. Things had changed in the years between the adoption of the torpedo and actual war. Long range shots at a Jutland style/size fleet never happened, in part because of the Japanese success at Pearl Harbor. There was no US battle fleet of 10-12 BBs and associated CAs and Cls traveling together with DDs screening them. The Actual actions involved mush smaller numbers of ships which which means smaller target area which usually called for closer ranges.
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As we know, there were quite a few of the smaller battles though with one or two BBs and / or a handful of CAs escorted by a dozen or two destroyers. And the Japanese torpedoes were quite telling in these.

Shortround6 said:
Yes the Japanese fired at longer ranges than the Allies did and took them by surprise but the over 30,000meter range may neve have been used in practice?
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We did a fairly thorough deep dive into this in this or one of the other threads as you probably remember. This, for me at any rate, showed that while 30,000 yard torpedo attacks may have been rare (not missing mind you, but yes rare), but what seemed to be the case was that all of the torpedoes were used at some fraction of their maximum range, normally, but the fraction for the IJN was much higher.

I recently watched a few videos on surface battles in the Pacific. One in particular by "Kings and Generals" had a very detailed and extremely interesting overview of naval, air and amphibious / land combat actions post Guadalcanal. They showed how the Japanese used patterns in their torpedo attacks and were still successfully surprising the Americans in several small engagements (this was in 1943) in which the Americans were still badly underestimating the effective range of the Type 93s.

The idea that they couldn't hit targets at extended range, or that they couldn't effectively shoot spreads of these based on limited sighting data, or that radar ended their advantages in night combat, or that they didn't still ad up to a major advantage for the IJN even this late in the game is I think, clearly a gross oversimplification.

Shortround6 said:
They were all good but in different degrees.
Japanese 18in aerial torpedoes don't seem to have much advantage over British 18in Torpedoes for most of the war. Both types were modified several times during the war so let's make sure we are comparing the correct versions and not comparing 1944 specs for earlier battles, for both sides.
Click to expand...

I won't debate the point on the air launched torpedoes, as I know the British were of good enough quality, but I would point out that most of the Japanese aircraft capable of delivering torpedoes were much better, in particular had much better range, than the FAA equivalents. The IJN also (arguably) had more effective long range land based aircraft for torpedo strikes, G3M and G4M bombers, though eventually the torpedo carrying Beaufighters would fit very well into this niche for the British.

Shortround6 said:
two different types of coordination, having flotilla flagship signal "attack enemy at bearing 115" is not giving firing solutions. A destroyer 4 ships back from the flagship is going to have a range 2000-4000yds different and a slightly different bearing. Same for float plane/s. The firing ship/s need to work out the exact range and correct bearing for the torpedoes to run at to hit the target or target area when the torpedoes get there. No two ships will fire at the exact same bearing because of their own locations in the formation.
A simultaneous launch rarely happened, there were often ripple launches or launches in turn as the firing fleet turned away. A lot depends on the bearing the enemy is at and the maneuver (turn) needed to clear the tubes to launch.
Now find an account that ship XXX fired their torpedoes on bearing 115 without seeing an enemy ship because the Flotilla commander said "fire torpedoes on bearing 115!"

They didn't fire guns that way, they at least fired at gun flashes.
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I can't say as I haven't read sources with that much granularity, though of course ripple launches, launching while turning etc. were all very common. The bottom line though is that the IJN clearly made it work over and over and over again.
 
Also Japanese DDs were not always way behind the BBs, BCs or heavy CAs, to the contrary the DDs and CLs were often far out front of the bigger ships with the big guns engaging the enemy fleets (task forces) with torpedoes.
 
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