Debate on the IJN type 93 torpedo

[Lecivius]

As I wander about the net, I came across what to me appears to be 2 different views on the type 93 'Long Lance' torpedo.

In one http://www.navweaps.com/index_tech/tech-067.htm it is noted...

"The first is a review of the Type 93 torpedo by range fired, and speed setting employed. The dismal performance in such long-range actions as Java Sea and Komandorski Islands, and the relative success in the close-range actions of the Solomons Campaign, imply that the weapon’s speed was a greater asset than its range. It may be that the Japanese misappreciated their own weapon and would have been better served by a plan which eschewed “long-range concealed firing” in favor of short-range attacks that offered the enemy less time to evade.

The second is a review of Type 93 dud and depth control problems. Numerous Type 93s failed to explode, many others ran under their targets and others prematured in the wake pattern of the target ship. Without detailed information on impact angles, Type 93 fuze characteristics, and the number of weapons which passed harmlessly beneath their targets, reliable observations regarding these factors (so famously poor in US submarine and aerial torpedoes) are impossible. What little information I have on these phenomena suggests the Type 93 was not immune to these banes of the torpedo designer and employer. "

This implies the torpedo did experience some ( though nowhere near all) of the issues the US Navy had with theirs. Yet a counterpoint can be found at http://www.combinedfleet.com/torps.htm

"Designing and perfecting the Long Lance required solving some extremely difficult technical problems, most of which centered around the usage of pure oxygen as a fuel (rather than compressed air). Compressed air is nearly 77% nitrogen, which is useless for combustion, and also contributes to the visibility of the torpedo by leaving a bubble track on the surface. The usage of pure oxygen promised far greater power and propulsive efficiency, but it came with certain costs. The most glaring of these was how to use pure oxygen safely aboard a ship or submarine, given its inherently inflammable nature. Premature detonation of the torpedo upon firing was also a problem. However, the Japanese overcame these hurdles. Further, through meticulous live-testing of their weapons against ship targets, they perfected a warhead detonator that was rugged and reliable (The U.S. Navy's BuOrd could certainly have taken a lesson or two here). The resulting weapon, the Type 93 torpedo, was fantastically advanced in comparison with its Western counterparts, possessing an unequaled combination of speed, range, and hitting power. This weapon, coupled with the flexible battle tactics practiced by Japan's cruisers and destroyers, led to victory after victory in the early stages of the war. Only as American radar and gunfire control became increasingly sophisticated would the Japanese advantage in night battles begin to disappear, and even then a Long Lance-armed Japanese destroyer was still a thing to be feared."

While not exactly specific to the actual efficiency of the type-93, it does indicate it was relatively bug free. Also, the Long Lance was not that effective in anything other than (relatively) close combat. It was not the range, but the speed, that was the deciding factor in hits scored. To me this appears to be in conflict.

Does anyone have thoughts or valid opinions? Perhaps other sources?

[Lecivius]

Found http://forum.worldofwarships.com/index. ... o-type-93/

Nothing about the potential defects, but interesting article anyways.

<edit>

http://pwencycl.kgbudge.com/L/o/Long_Lance.htm

PWE seems to indicate that the depth & exploder issues were resolved prior to war's outbreak. But it still appears speed and power, not range, were the major causes for success.

<re-edit>

http://www.ww2pacific.com/torpedo.html

Nothing on the T 93, but a wealth on the US Torpedo woes. Reading this, it appears the game developers were actually pretty generous with the successful hit ratio of allied torpedoes [X(]

[spence]

The type 93 was a ship killer but not all the ships it killed were Allied. Any fire in the vicinity of the torpedo tubes of an IJN warship was almost certain to cause the oxygen propelled torpedoes to both detonate and feed the fire to such an extent as to seriously imperil the ship. The experiences of the two sister ships Mogami and Mikuma when hit by bombs at Midway is illustrative: after both ships suffered bomb hits midships and consequent fires near the torpedo tubes the Damage Control Officer on Mogami jettisoned his torpedoes and his ship survived. The DCO on Mikuma did not and his torpedoes exploded dooming his ship. The fire danger posed by one's own torpedoes was the principle reason that they were removed from (or omitted from the design of) USN heavy cruisers.

By no means was Mikuma the only IJN ship killed by its own torpedoes...IIRC 3 CAs and 2CLs and several DDs were effectively destroyed by the sympathetic detonation of their own torpedoes.

[Rising-Sun]

Hard to believe those thing can fire and forget at night, traveling at high speed up to 40,000 yards. Believe that what USN got hit the most in the Solomon Islands near Guadalcanal or down the Slot. The two kuma class Kitakami and Oi is nasty during night naval engagement.

[spence]

Hard to believe those thing can fire and forget at night, traveling at high speed up to 40,000 yards. Believe that what USN got hit the most in the Solomon Islands near Guadalcanal or down the Slot. The two kuma class Kitakami and Oi is nasty during night naval engagement.

_____________________________

Neither of those two ever engaged in a surface battle. The IJN modified both of those cruisers by removing their torpedo tubes (TROMs from CombinedFleet.com). Hmmmm?

[Lecivius]

Also, they had a 2 step launch sequence. The initial launch was done using standard compressed air, with oxygen taking over from a separate single piece machined bottle (from armor grade steel no less) a few moments after motor ignition. It was this 2 step process that gave it the range and bypassed a lot of the British problems, from what I can find so far.

Interesting stuff out there.

[Rising-Sun]

ORIGINAL: spence

Hard to believe those thing can fire and forget at night, traveling at high speed up to 40,000 yards. Believe that what USN got hit the most in the Solomon Islands near Guadalcanal or down the Slot. The two kuma class Kitakami and Oi is nasty during night naval engagement.

_____________________________

Neither of those two ever engaged in a surface battle. The IJN modified both of those cruisers by removing their torpedo tubes (TROMs from CombinedFleet.com). Hmmmm?

I know those two never took place in the Solomon, but I just realize this only ship was in the Solomon had type 93 TT mounts (Chokai) others are Aoba Class. But imagine having Kita and Oi with those 93s it would been a wall of steel heading their way.

http://en.wikipedia.org/wiki/Japanese_c ... h%C5%8Dkai

http://en.wikipedia.org/wiki/Type_93_torpedo

[wdolson]

I recall posting the original article a while back. I did find it interesting.

The problem with the Oi and Kitikami would have been whether they had been hit by gunfire before launching or not. Even 5 inch fire on the run in may have set off one of more torpedoes with catastrophic results, the Mikuma was done in by exploding torpedoes and she was a much larger and more modern ship than the Oi class. But as the navweapons article points out that Japanese torpedoes weren't as good as they were advertised to be. In action they only achieved about 1/3 the results pre-war planning said they had to achieve.

Bill

[Hyacinth]

ORIGINAL: wdolson

I recall posting the original article a while back. I did find it interesting.

The problem with the Oi and Kitikami would have been whether they had been hit by gunfire before launching or not. Even 5 inch fire on the run in may have set off one of more torpedoes with catastrophic results, the Mikuma was done in by exploding torpedoes and she was a much larger and more modern ship than the Oi class. But as the navweapons article points out that Japanese torpedoes weren't as good as they were advertised to be. In action they only achieved about 1/3 the results pre-war planning said they had to achieve.

Bill

Launched in large salvoes at night and undetected they should work as advertised, do they?

[Hyacinth]

Also targets being mainly capital ships, they where not ment to catch small fish.
Radar made this tactic only possible in confined waters, totally plausible in Solomons, dont think the game engine can model this.

[wdolson]

The navwespons site goes over every time Japanese surface ships used the type 93. At the Battle of the Java Sea 167 were launched with a hit rate of 1.8%. At the Battle of Vella Lavella, 48 were launched with a 4.1% hit rate. The Battle of Biak had 42 launched, no hits. Empress Auguta Bay, 44 launched, 0 hits.

The Oi and Kitikami could only launch half their load in a salvo, the tubes were half to a side, which meant 20 per side. But we will never know if the concentrated salvo would do any good. 20 torpedoes launched from one point is probably not as dangerous as 20 launched from multiple points. And there are 4 instances where the Japanese managed to get 40 or more fish in the water and managed 167 in one instance early in the war (when the Allies didn't have radar) and the results were pathetic.

Torpedoes are devastating when they hit, but the results in the war showed surface launched torpedoes were more effective at throwing off the aim of ships firing guns than actually doing much damage.

Bill

[Dili]

Hit rate is not relevant if we don't get a hit rate from a comparable range from other torpedo models - and also night/day. So like in ship gunnery we have very low samples to judge.
But nevertheless it was very rare for any torpedo to hit at more than 3-4km.
So that part of Japanese doctrine was wrong, it could turn right if the enemy was forced to split their forces while maneuvering from torpedoes, but that wasn't the idea behind Japanese long range request.

[Hyacinth]

ORIGINAL: wdolson

The navwespons site goes over every time Japanese surface ships used the type 93. At the Battle of the Java Sea 167 were launched with a hit rate of 1.8%. At the Battle of Vella Lavella, 48 were launched with a 4.1% hit rate. The Battle of Biak had 42 launched, no hits. Empress Auguta Bay, 44 launched, 0 hits.

The Oi and Kitikami could only launch half their load in a salvo, the tubes were half to a side, which meant 20 per side. But we will never know if the concentrated salvo would do any good. 20 torpedoes launched from one point is probably not as dangerous as 20 launched from multiple points. And there are 4 instances where the Japanese managed to get 40 or more fish in the water and managed 167 in one instance early in the war (when the Allies didn't have radar) and the results were pathetic.

Torpedoes are devastating when they hit, but the results in the war showed surface launched torpedoes were more effective at throwing off the aim of ships firing guns than actually doing much damage.

Bill

It is a good analysis but it fails little short in comparing battles that where not fought as defined in the IJN doctrine.

None fit doctrine perfectly, most dont at all.

In Java Sea for instance IJN was defending a landing, not charging suicidally at capital ships.
They did sink two light cruisers, with torpedoes.

In some they where on a supply run and ambushed, not ambushing themselves.

Some are late war battles that have the suicidal part correct and a technological revolution happening inside the past few years.

With different samples the percentages go up.



http://www.navweaps.com/index_tech/tech-067.htm

[wdolson]

The history of torpedo attacks underlines the fallacies underlying the strategy. The conditions under which their ships were designed to fight rarely came close to reality and they never saw the exact kind of condition their ships were designed to fight.

Overall I think USN doctrine was probably better. It was more flexible to conditions (especially early war) and ships were more readily refitted to fight the kind of war they were facing rather than trying to create the conditions that would best fit their designs.

The changes on US DDs demonstrated this the best. When ASW assets proved inadequate, the DDs got a lot more ASW. To deal with air threats, the AA was upgraded, many Fletchers even lost a 5 inch gun to get an extra pair of 40mm tubs. As the war went on many US DDs also traded in their torpedoes for more AA. In 1945 a lot of DDs were being refitted for minesweeping. Some Gearing class DDs were refitted before going to the Pacific for the first time.

The Japanese too refitted ships as the war went on, but they were slow to add AA and ASW and their AA was never as effective as USN AA. The Japanese were slow to remove torpedoes from their ships, and the practice of carrying reloads made them more vulnerable when hit near torpedo mounts. Even the Japanese must have seen something wrong with the loadout of the Oi and Kitikami because they didn't keep the torpedo cruiser layout for all that long. They were converted to transports only a year or so after the torpedo cruiser conversion.

Japan had a critical shortage of cruisers throughout the war. These two would have been much more useful in their original layout. As it was they were eventually converted to semi troop transports.

Bill

Bill

[Hyacinth]

ORIGINAL: wdolson

The history of torpedo attacks underlines the fallacies underlying the strategy. The conditions under which their ships were designed to fight rarely came close to reality and they never saw the exact kind of condition their ships were designed to fight.

Overall I think USN doctrine was probably better. It was more flexible to conditions (especially early war) and ships were more readily refitted to fight the kind of war they were facing rather than trying to create the conditions that would best fit their designs.

The changes on US DDs demonstrated this the best. When ASW assets proved inadequate, the DDs got a lot more ASW. To deal with air threats, the AA was upgraded, many Fletchers even lost a 5 inch gun to get an extra pair of 40mm tubs. As the war went on many US DDs also traded in their torpedoes for more AA. In 1945 a lot of DDs were being refitted for minesweeping. Some Gearing class DDs were refitted before going to the Pacific for the first time.

The Japanese too refitted ships as the war went on, but they were slow to add AA and ASW and their AA was never as effective as USN AA. The Japanese were slow to remove torpedoes from their ships, and the practice of carrying reloads made them more vulnerable when hit near torpedo mounts. Even the Japanese must have seen something wrong with the loadout of the Oi and Kitikami because they didn't keep the torpedo cruiser layout for all that long. They were converted to transports only a year or so after the torpedo cruiser conversion.

Japan had a critical shortage of cruisers throughout the war. These two would have been much more useful in their original layout. As it was they were eventually converted to semi troop transports.

Bill

Bill

Early war there was no battle line to send forward for the USN or to engage at for the IJN.

It could have been a blessing in disguise..
If politicians would have forced the USN to try and relieve the Philippines it could have ended with much worse losses (the carriers) that resulted from Dec 7.

IJN got sucked in to an attritional piece meal campaign of no strategic value in the Solomons and went to the "decisive battle" in Midway weakened by that and OPSEC breached.

[crsutton]

Massed torpedo attacks were obsolete by the middle of 43. Improved radar and fire control widened the range of engagement to the point where surface gunnery could neutralize Japanese ships well outside of effective range successful torpedo attacks. Oddly enough the situation was reversed for the Americans. Improved American torpedoes along with the Japanese failure to produce radar effective enough to reliably detect surfaces ships allowed the Americans to have some success long after torpedoes had lost their sheen. Torpedoes did not become much of a threat again until homing and guided torpedoes became more reliable after the war.

[Rising-Sun]

Actually Japan was short on escorts and DDs to support the screen of capitol ships.

During engagements, when torpedoes are in the water, I believe the system will check to see if this is night or day. Night time would be almost impossible to see the torpedoes coming, but during the day, believe the system will check to see if the torpedoes have been spotted and trying to maneuver them, the smaller ships would have better chance to maneuver than larger ships. Radars would have no effects on this situations, pretty much there not much you can do while these torpedoes in the water. Now the percentage of moonlight during night engagement, I believe there small chance to spot them.

[wdolson]

I don't know exactly what the code does, but in the real war, Allied crews knew what a torpedo run looked like on radar and would know to be alert for torpedoes in the water when they saw smaller ships charging towards them at flank speed then suddenly turning to expose the torpedo racks.

Bill

[Dili]

ORIGINAL: wdolson

The history of torpedo attacks underlines the fallacies underlying the strategy. The conditions under which their ships were designed to fight rarely came close to reality and they never saw the exact kind of condition their ships were designed to fight.

Overall I think USN doctrine was probably better. It was more flexible to conditions (especially early war) and ships were more readily refitted to fight the kind of war they were facing rather than trying to create the conditions that would best fit their designs.

The changes on US DDs demonstrated this the best. When ASW assets proved inadequate, the DDs got a lot more ASW. To deal with air threats, the AA was upgraded, many Fletchers even lost a 5 inch gun to get an extra pair of 40mm tubs. As the war went on many US DDs also traded in their torpedoes for more AA. In 1945 a lot of DDs were being refitted for minesweeping. Some Gearing class DDs were refitted before going to the Pacific for the first time.

The Japanese too refitted ships as the war went on, but they were slow to add AA and ASW and their AA was never as effective as USN AA. The Japanese were slow to remove torpedoes from their ships, and the practice of carrying reloads made them more vulnerable when hit near torpedo mounts. Even the Japanese must have seen something wrong with the loadout of the Oi and Kitikami because they didn't keep the torpedo cruiser layout for all that long. They were converted to transports only a year or so after the torpedo cruiser conversion.

Japan had a critical shortage of cruisers throughout the war. These two would have been much more useful in their original layout. As it was they were eventually converted to semi troop transports.

Bill

Bill

I think was more the benefit of having no doctrine. That is better in a situation where technology evolves fast.

The Oi,Kitakami case maybe that they were lousy ships with short range and not much speed, eventually dubious stability.

ORIGINAL: wdolson

I don't know exactly what the code does, but in the real war, Allied crews knew what a torpedo run looked like on radar and would know to be alert for torpedoes in the water when they saw smaller ships charging towards them at flank speed then suddenly turning to expose the torpedo racks.

Bill

Yes, but could be a feint attack.

[Rising-Sun]

ORIGINAL: wdolson

I don't know exactly what the code does, but in the real war, Allied crews knew what a torpedo run looked like on radar and would know to be alert for torpedoes in the water when they saw smaller ships charging towards them at flank speed then suddenly turning to expose the torpedo racks.

Bill

Didn't think the radars could pick them up, sonar perhaps?