Long lance torpedoes

[Troy Tempest]

A mate posted this on an IMDb board, and not knowing anything about Japanese torpedoes, I thought I'd post it here so see what you guys thought:

It's well-known that the Japanese Type 93 torpedo used compressed oxygen instead of compressed air as the oxydizer for its wet heater engine. This, combined with its immense size (nearly 3 tons), gave it exceptional range and speed, even while carrying the largest warhead of its day. What is not as well-known is the price the Japanese paid for this performance.

Six Japanese cruisers were sunk due, at least in part, to fires and/or explosions among their oxygen torpedoes.

6 June 1942: Mikuma is hit by bombs, fire breaks out among the torpedoes, torpedoes explode, ship sinks. (Sister Mogami, also bombed that day, has already jettisoned her torpedoes and survives.)

11 October 1942: Furutaka hit by American naval gunfire at night, fires almost immediately break out among her torpedoes, illuminating the ship, apparently drawing more gunfire. Ship is sunk.

3 April 1943: Aoba is hit by bomb from a B-17, torpedoes explode, ship is beached to avoid total loss. Later salvaged.

25 October 1944: Mogami hit by two American 8-inch shells. Fire breaks out, she collides with Nachi (her third collision of the war), then her torpedoes explode. She is bombed and torpedoed again by American aircraft, and finally must be scuttled.

25 October 1944: Suzuya is missed by bombs, but fragments from near misses ignite fires among her torpedoes, torpedoes explode, ship sinks.

25 October 1944: Abukuma is hit by 3 bombs dropped by B-24s. Fires detonate 4 Type 93 torpedoes, ship sinks.

Now I ask, were these torpedoes really the best? It turns out that few hits were obtained by oxygen torpedoes from Japanese cruisers that could not have been managed by regular compressed-air torpedoes. The damage listed above exceeds the total of that extra damage due the the performance of oxygen torpedoes. It's a net loss.

There's more. On one occasion, some Japanese torpedoes missed their intended targets (Allied cruisers USS Houston and HMAS Perth) and went far into the distance to hit some Japanese transports. There may be such a thing as too much range in an unguided weapon.

Troy

[Eugen Pinak]

And "the funniest" thing is that the risk of damage from your own torpedoes was perfectly known to the Japanese (creator of "standard" Japanese heavy cruiser design - Hiraga, was strong opponent of such design feature) - but they choose to take the risks

[ChristopherPerrien]

Now I ask, were these torpedoes really the best? It turns out that few hits were obtained by oxygen torpedoes from Japanese cruisers that could not have been managed by regular compressed-air torpedoes. The damage listed above exceeds the total of that extra damage due the the performance of oxygen torpedoes. It's a net loss.

.
Troy

The problems you site are not because of the torpedoes themselves, rather the doctrine of arming heavy cruisers with torpedoes. The Long lance was by far the best torpedo in the war and if you are going to pile torpedoes on the deck of ship, you might as well use the best. This " fire/explosion hazard" was a problem for any ship that carried torpedoes or depth charges of any nation in WWII.

Your examples make note of this, however the incidences you cite of exploding torpedoes only caused "fires" on these ships and the sinking of the ship in most of these cases cannot be attributed primarily to these. I will side with you as to saying torpedoes on heavy cruisers is not a good idea , but it is not because of the design/capabilities of the Long Lance torpedo.

There's more. On one occasion, some Japanese torpedoes missed their intended targets (Allied cruisers USS Houston and HMAS Perth) and went far into the distance to hit some Japanese transports. There may be such a thing as too much range in an unguided weapon.

You are ignoring the whole forest for a "shrub".

Incidents of friendly fire , could be used to disparage every weapon of war since man started fighting wars, including "rocks". The range of the Long Lance was something every nation and combatant in WWII would have wished for their own torpedoes.

What the Japanese should have done given the range of the Long Lance was to program a "circling" function in the guidance system if the torpedo exceeded the range to target.

Chris

[cstunts]

Hello,

IIRC the USN made a decision to remove torpedo tubes or not include them at all on CAs under construction or in planning because we foresaw little tactical use for them, as well as the dangers they posed to their own ships.

And make no mistake, the Japanese were quite worried about the lethality of these weapons and their potential dangers in restricted waters -- as at Bantam Bay. Oddly enough the day before they had experienced many problems with these torpedoes due to premature detonations during the Battle of the Java Sea.

FWIW

[Peter H]

"The Performance of Japanese Surface Forces in Torpedo Attack versus the expectations of the Decisive Battle Strategy"

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

[Wargames]

The "long lance" torpedo was a superior torpedo to the American torpedo. To argue IJN ships should not have carried them is to argue US ships should not have carried torpedoes either. In ship to ship combats, the Japanese were at a significant advantage to US ships, owing in a large part, to their torpedoes.

The argument that IJN ships were at risk from their own torpedoes while under air attack is meaningful only if US ships were not at risk from their own torpedoes while under air attack. Otherwise, a torpedo is a torpedo. Set a ship on fire carrying torpedoes and you can expect them to explode regardless of what country they were built in.

The subject here is either IJN damage control or IJN torpedo value. If Japanese ships were sunk by their own torpedoes exploding then they should have been jettisoned as part of damage control procedure versus designing the ship without them. Air attack has nothing to do with the value of the weapons themselves. As for IJN torpedo value, it was the best in the world.

And, so far as placing them aboard CA units, the ships so equipped benefitted from it, particularly in night actions. The argument of whether a ship should be equipped with torpedoes or not is directly related to expected combat ranges. Clearly, HMS Hood had no use for torpedoes and they proved a liability and not an asset. Since Japanese CA units were without radar, their night combat ranges included Japanese torpedo ranges.

[donsor]

Us torpedoes during much of the war used flasks charged with 3k pounds of compressed air. when launched, there is an alcohol fueled igniter which heats up the compressed air to increase expansion allowing higher air pressure to drive the turbine that drives two counter rotating propellers. How was the Japanese torpedo propelled?

[LWD]

The "long lance" torpedo was a superior torpedo to the American torpedo.

At the beginning of the war this is clearly the case. By the end it is at least arguable. While late war US torpedos didn't have the range they and warheads that were approaching that of the long lance (at least early versions) and in a smaller package so more could be carried.

The argument that IJN ships were at risk from their own torpedoes while under air attack is meaningful only if US ships were not at risk from their own torpedoes while under air attack. Otherwise, a torpedo is a torpedo. Set a ship on fire carrying torpedoes and you can expect them to explode regardless of what country they were built in.

Par tof the problem here is the nature of the Japanese torpedos. ie it is not correct to say "a torpedo is a torpedo" . The long lance relied on compressed oxygen. In the pressence of pure oxygen most things on a ship become flamable. Furhtrermore the oxygen could not be stored in the torpedos indefinitily so facilities had to be on board ship to recharge it. The oxygen may have been a more serious threat in many ways than the warhead. One of the outstanding successes of Japanese damage control occured at Midway (on the Tone ?) where the Japanese damage control officer took the unusual initiative to jettison the torpedos after the ship was damaged. Had these been on board when the ship was hit later in the day she woulld very likely have been lost at that point.

...

And, so far as placing them aboard CA units, the ships so equipped benefitted from it, particularly in night actions....

And they also clearly had problems because of it. Note that the Japanese DD's were more successful with their torpedos than the CAs

The argument of whether a ship should be equipped with torpedoes or not is directly related to expected combat ranges. Clearly, HMS Hood had no use for torpedoes and they proved a liability and not an asset. Since Japanese CA units were without radar, their night combat ranges included Japanese torpedo ranges.

No it is not the expected combat ranges but the expected mission. The long lance had a range similar to that of battle ship guns (although few if any hits could be expected at that range). The rational for including them on the Japanese CAs was that they were to be used to attrit the US battle line prior to it being engaged by the Japanese battle line in the planned "decisive battle". For this reason it was rational to include the long lances on the CAs.

[donsor]

From my vague memory of chemistry, oxygen it itself is not combustible. Its one of the three elements for combustion (explosion, oxidation to occur) the other would be fuel and temperature. In case of an explosion, I can see it "fanning" the fire but other than that it shouldn't be that dangerous.

Further, as opposed to the present wire guided, sound, proximity, and other good things regarding modern torpedoes, WWII torpedoes were usually fired in a spread hoping that one will hit the target. That is, once the gyro angle and depth are set, once it leaves the tube, it's on it's own. Thus the farther away the target, a fast moving target at that, the less likely that it will get hit. So, of the 21 odd torpedoes most subs carry (US), firing a spread of six is only "cost-effective" when directed towards a large target such as a CV or BB.

[Troy Tempest]

Thanks again for all your input, as I re-posted this thread question from another site, as I had no idea of the answers, here is the original post on the Saving Private Ryan IMDb board if you want to see some other answers that have come through since I posted it here ;

http://www.imdb.com/title/tt0120815/boa ... 4#64162094

Thanks again for your help!

Troy

[OHara]

Best torpedo or the torpedo with the most impressive characteristics? I think the Type 93 had several faults that limited it effectiveness. It had a large wander value - something to consider when used at long ranges and it had overly sensitive detonators. But, you have to think what the Japanese intended it for and how they used it. It was a secret weapon designed to seize a long range advantage in a specific type of surface engagement. Moreover, what other nation saturated the water with salvos of one hundred or more torpedoes?

Vince

[ChristopherPerrien]

Thanks again for all your input, as I re-posted this thread question from another site, as I had no idea of the answers, here is the original post on the Saving Private Ryan IMDb board if you want to see some other answers that have come through since I posted it here ;

http://www.imdb.com/title/tt0120815/boa ... 4#64162094

Thanks again for your help!

Troy

Your welcome,

However your link is SPAM, as it asks for all kinds of info to read the posts. I was sort of suprised for me on personal note since I think I have an account at IMDb already. Anyway it made me go back and look at your first post , and although I missed it on your first post, you should have put the comments of your "mate" in quotes. Rarely will I reply to something that someone else just "heard' , as it is not debating "first person" and you cannot really debate a third person idea/theory, I missed this on your first post because of my own oversight and the lack of "quotes".

Chris

[Troy Tempest]

Sorry Chris!

Troy

[LWD]

From my vague memory of chemistry, oxygen it itself is not combustible. Its one of the three elements for combustion (explosion, oxidation to occur) the other would be fuel and temperature. In case of an explosion, I can see it "fanning" the fire but other than that it shouldn't be that dangerous.
....

In the presence of pure oxygen or even purer oxygen it takes only a little heat and a carbon containing material to start a fire. A common example of this in chem labs it to melt potassium nitrate and drop in some carbon containng item such as sugar or wood. Things like paint, rubber, oil, wood, etc take little more than a spark to start on fire in the presence of pure oxygen and extinquishing the fire becomes more problematic as the fires are hotter and it is harder to seperate the combustables from the oxygen. Even if you can seperate the two there may be enough heat left in the metal to reignite combustion once the foam, co2, or water are gone. Pure oxygen can also be quite corrosive especially where metals are concerned rust is afterall iron oxide.

[cstunts]

Hello,

Campbell has a brief section decribing the safety measures adopted by the IJN when these systems were in operation. Pure oxygen such as used in the Type 93 was remarkably dangerous, as a chemical engineer said to me once with a shuddder, "Man, you wouldn't want that stuff getting loose anywhere!" It may be of interest to note that the technology for the oxygen plants installed on the CAs and DDs came from cooperation with French firms (in the late Twenties, early Thirties, IIRC) including Air Liquide.


Regards