Slitherine

quote:

ORIGINAL: anarchyintheuk


All true, but among those materials listed only torpedoes combine explosiveness, an open placement and a lack of armor.

quote:


Maybe chicken v. egg. Thinking those jettisons occurred after the Mikuma, which set the doctrine to jettison in case of danger.

quote:

ORIGINAL: Nikademus

quote:

ORIGINAL: anarchyintheuk


All true, but among those materials listed only torpedoes combine explosiveness, an open placement and a lack of armor.

and Depth Charges, and ready AA ammo. While not "open" some HA/secondary ammo spaces were also unarmored, or lightly armored in similar respect to the light armor protecting the torpedo warheads.

quote:


Maybe chicken v. egg. Thinking those jettisons occurred after the Mikuma, which set the doctrine to jettison in case of danger.

Possibly, but I found no such indication of any change after Mikuma. It appeared to be standard response, similar to the flooding of threatened magazine spaces. My main focus was to point out if the danger was great enough, the Japanese could and did jettison their torpedoes as a matter of procedure. It had been suggested in the past that they would not and that Mogami was an aberation. I found this not to be the case.

quote:

ORIGINAL: Ryvan

quote:

ORIGINAL: Nikademus

quote:

ORIGINAL: Ryvan


Which didn't prevent 2 of the 4 Mogami class ships from being sunk by their own torpedoes. Mikuma was destroyed when fire reached her torpedoes. Suzuya was sunk by a bomb that never struck the ship, but the concussion of the miss caused her torpedoes to denotate and sink her. Mogami herself was scuttled after being crippled by her own torpedoes exploding due to a fire caused by Nachi ramming her. Chokai, of the Takao class, was also crippled by explosion of her own long lances.

A ship that stores explosive weapons is always subject to the risk of explosions. Torpedoes are no different than heavy shells or depth charges in this respect. Operationally speaking, the storage and use of o2 torpedoes was no more dangerous than the other types of weapons. It was operational accidents that made the British abandon o2 torpedoes but not torpedoes in their entirety. The Japanese suffered no operational accidents either during peacetime or in wartime.

It is true that the Japanese navy suffered torpedo explosions in combat. Unsuprising given the ahilating battle that they faced vs the US air and sea power. However in a study conducted on damage to Japanese cruisers in total, i found the incident rate involving torpedoes only constituted 5.5% of the total damage suffered. Eric Lacroix's definitive and exhaustive study of IJN cruisers takes a netural stance on the issue of torpedo armed cruisers (and battleships). Note that he says "torpedoes", not "Type 93 Long Lance torpedoes". In accessing the danger, he points out that it was the large warhead sizes of the various torpedo models, not o2, which presented the danger, as shown in the Tosa experiment. He concludes that wartime experiences supported both Hiraga's and the General Staff's views on torpedo armament. (Hiraga - against/General Staff - for) Torpedoes were used successfully in several occasions during the war but in the debit side, the loss of Mikuma, Furutaka, and Suzuya could be directly attributed to explosion of on-board torpedoes, while two others, Mogami and Aoba were damaged severely by explosions. There is no conclusive evidence that Chokai was the victim of a torpedo expolsion. Only the Combined Fleet "TROM" (Table of Organized Movement) describes her as a victim of a torp explosion but Neither Lecroix, Cuttler, or Hornfischer can confirm it though the latter author "suggests" that a secondary explosion may have been a torpedo. Given Lecroix's analysis is the most detailed i put the greatest weight with this author over an online TROM.


My personal take on it....the Japanese navy was built to fight a surface action against a superior numbered foe, hence torpedoes were part of that solution. However the emergence of the airpower as the dominant tool made torpedoes less useful (and potentially more dangerous) as a result. By 45, even USN DD's were removing torpedo mounts in favor of additional AA. Air attack accounted for 4 of 6 confirmed incidents of torpedo ignition/detonation. (there were also 4 incidents involing torpedo/torpedo mounts where no ignition or explosion occured)

Other negating factors - While Mikuma's loss was ensured by torpedo detonation, it was not due to the nature of the Type 93 nor of torpedoes in general...it was due to the negligence of the ship's DC officer who refused in the face of highly probable air attack to jettison his clutch of torpedoes. Given Mogami's experience the ship might have been lost anyway but this act more than anything doomed the ship. Mogami's DC did jettison the torpedoes per doctrine and while close....did survive. She would later be badly damaged by a torpedo explosion in 1944 before a jettison order could be carried out but in the end she was ordered abandoned by her captain after serious fires were started by two 500lb bomb hits well after the incident. Aoba was severely damaged by air attack, while in port and stood down.

In conclusion, I don't personally consider the destruction of the British DD Khartoum by a torpedo explosion nor the self torpedoing of the British cruiser Trinidad, along with the above experiences of the IJN to be proof that torpedoes were more a danger to the operating ships than to the enemy. Ordinance is always potentially dangerous. In *game terms*, the possibility of catastrophic explosion is already in the game at 4% chance per penetration. (Tower armor Hit location excluded). So 5.5% vs. 4%. Not signifigant in my opinion.

I take no position on whether the warheads or the O2 was responsible for the damage. The facts show that the long lance seems to have been significantly more dangerous to carry than other types. I can't think of any other cruiser class ships that were destroyed by their own torpedoes onboard, (although I will grant that often they are simply listed as having had "secondary explosions" which may or may not have involved their torpedo ammo.) I also can't think of situations where cruiser crews purposely jettisoned weapons overboard when air attack was expected other than long lance armed ships. I certainly don't know of any other ship sunk by her own ammo, of any type, cooking off after the ship was missed by a bomb. Is this a significant enough history that it should be modeled in game? That's open for debate. Personally, I think it pretty much already is modeled by the Allied Damage Control option. The only thing that would be "more realistic" would be to have long lance equiped ships have a chance to jettison their torpedo ammo if brought under air attack. I don't think it's a significant enough issue to worry about though.

quote:

ORIGINAL: Ryvan


Which didn't prevent 2 of the 4 Mogami class ships from being sunk by their own torpedoes. Mikuma was destroyed when fire reached her torpedoes. Suzuya was sunk by a bomb that never struck the ship, but the concussion of the miss caused her torpedoes to denotate and sink her. Mogami herself was scuttled after being crippled by her own torpedoes exploding due to a fire caused by Nachi ramming her. Chokai, of the Takao class, was also crippled by explosion of her own long lances.

quote:

ORIGINAL: Ryvan
Was it a matter of procedure in case of air attack? Or procedure in case of fire on board in the area of torpedoes? There really isn't a lot of information available on this that I can find. One thing you didn't mention as being unprotected would be refueling hoses on carriers. There were indeed a ton of unprotected things that could explode on pretty much any combat ship.

quote:

but was it because the torpedoes were inherently more dangerous due to their oxygen use, or was it because the Japanese ships came under effective air attack more often than any other navy in the war

quote:

ORIGINAL: Nikademus

quote:

ORIGINAL: anarchyintheuk


All true, but among those materials listed only torpedoes combine explosiveness, an open placement and a lack of armor.

and Depth Charges, and ready AA ammo. While not "open" some HA/secondary ammo spaces were also unarmored, or lightly armored in similar respect to the light armor protecting the torpedo warheads.

quote:

ORIGINAL: mdiehl

quote:

but was it because the torpedoes were inherently more dangerous due to their oxygen use, or was it because the Japanese ships came under effective air attack more often than any other navy in the war

Both the oxy use and the size and greater instability of Japanese explosives esp as when exposed to heat. And no, other navies did not have that problem. The USN, Kriegsmarine, and RN all worked experimentally in the 1920s with oxy-driven torpedoes and all of them rejected the designs on account of the hazard they posed.

quote:

ORIGINAL: bklooste

Speaking of which why was the Japanese Fire DC so poor , they seem to recover from hits pretty well and flooded well but rarely fire ? I couldnt imaging there ships having many creature comforts steel , steel and more steel.

quote:

ORIGINAL: Shark7

quote:

ORIGINAL: bklooste

Speaking of which why was the Japanese Fire DC so poor , they seem to recover from hits pretty well and flooded well but rarely fire ? I couldnt imaging there ships having many creature comforts steel , steel and more steel.

The decks of some of the destroyers were linoleum. So basically a highly flammable material covered the entire topside of the ship. Could be a source of the fires.

quote:

ORIGINAL: bklooste

quote:

but was it because the torpedoes were inherently more dangerous due to their oxygen use, or was it because the Japanese ships came under effective air attack more often than any other navy in the war

That was the hazzard fueling them, not once fueled, anyway Oxgen is not an issue on the open deck of a ship as it is not a confined space any fire will get plenty of Oxygen and cant be starved. The 2-3 tons of fuel *5-6 does make a pretty big fire whether you have Oxygen or not.

quote:


Speaking of which why was the Japanese Fire DC so poor , they seem to recover from hits pretty well and flooded well but rarely fire ? I couldnt imaging there ships having many creature comforts steel , steel and more steel.

quote:

ORIGINAL: Nikademus

quote:

ORIGINAL: bklooste

quote:

but was it because the torpedoes were inherently more dangerous due to their oxygen use, or was it because the Japanese ships came under effective air attack more often than any other navy in the war

That was the hazzard fueling them, not once fueled, anyway Oxgen is not an issue on the open deck of a ship as it is not a confined space any fire will get plenty of Oxygen and cant be starved. The 2-3 tons of fuel *5-6 does make a pretty big fire whether you have Oxygen or not.

Hi,

The degree of air attack was a major contributing factor. 4 of 6 incidents involving torpedo explosions was due to air attack. The large warhead sizes and numbers did make for a higher degree of hazzard, not 02 or any issue with the type of explosive used. The Japanese, as cited earlier, suffered no operational accidents while handling/refueling their torpedoes, o2 or otherwise. They had solved the potential problems that bedeviled British and US efforts to deploy similar 02 torps. (Lecroix - Japanese Cruisers of the Pacific War)

quote:


Speaking of which why was the Japanese Fire DC so poor , they seem to recover from hits pretty well and flooded well but rarely fire ? I couldnt imaging there ships having many creature comforts steel , steel and more steel.

DC in the Japanese navy was not as well focused on vs. the US navy which improved drastically as the war progressed. While not universally poor in all instances, I did note a good number of cases involving Japanese cruisers whereby progressive flooding and firefighting proved exceedingly difficult to control which led to additional problems....including secondary explosions (some involving the torpedoes naturally). While the British and Americans had some issues, particularily the former (such as the Southhamptom incident....a reletively lightly damaged cruiser of which the fires could not be brought under control forcing the ship to be scuttled eventually), overall their DC efforts produced better results and I feel that had some of these incidents occured in the USN in particular the fires and flooding would have been brought under control quicker, at least from late 42 onward as USN DC procedures sharpened and improved through wartime experience.

quote:

ORIGINAL: bklooste

I feel the same i think in 4 of the 5 cases with Western DC those torpedos would not have been lost. As a comparison Depth Charges caried the same explosive type as the torps and in much greater quantities. eg 48 depth charges would be 9000-20000 lbs. Yet few people think haveing these as a big issue .

quote:



I see very few Allied DDs lost to Depth charges ot Torpedos despite the much greater explosive than the Japanese Cruisers. Speaking of which why werent many Japanese DDs lost for the same reason "? Did armouring the torps make it worse ?

quote:

ORIGINAL: bklooste

quote:

ORIGINAL: Shark7

quote:

ORIGINAL: bklooste

Speaking of which why was the Japanese Fire DC so poor , they seem to recover from hits pretty well and flooded well but rarely fire ? I couldnt imaging there ships having many creature comforts steel , steel and more steel.

The decks of some of the destroyers were linoleum. So basically a highly flammable material covered the entire topside of the ship. Could be a source of the fires.

Was this on the other ships ? It seems to be all the ships CVs , CAs especially the BBs seemed to have faired better for fires though the Kongos were the worst.

quote:

That was the hazzard fueling them, not once fueled, anyway Oxgen is not an issue on the open deck of a ship as it is not a confined space any fire will get plenty of Oxygen and cant be starved. The 2-3 tons of fuel *5-6 does make a pretty big fire whether you have Oxygen or not.

quote:

ORIGINAL: Miller

I have not read this post but I would just like to say in a recent surface combat my fleet of 18 DDs (vs 1 CA, 3 CL and 8 DDs) fired a total of 250 torpedoes and scored no hits....

quote:

ORIGINAL: Panther Bait

Considering that torpedoes and DCs are designed to explode under water (where there isn't a lot of free oxygen), it seems to me that the explosive itself must contain the more than enough oxygen to support the explosion.  Therefore, it's debatable whether extra oxygen  in the area from a ruptured torpedo oxygen bottle (as opposed to extra oxygen in the explosive itself) would make the warhead more dangerous or the explosion of the warhead that much worse.

What the oxygen would possibly do is make any secondary fires started by the warhead explosion worse, and if the oxygen bottle ruptured first, the concentrated oxygen could obviously start fires (with an ignition source, which aren't hard to find in combat).

quote:

Therefore, it's debatable whether extra oxygen in the area from a ruptured torpedo oxygen bottle (as opposed to extra oxygen in the explosive itself) would make the warhead more dangerous or the explosion of the warhead that much worse.

quote:

Do they actually explode underwater

quote:

ORIGINAL: Shark7

quote:

ORIGINAL: Panther Bait

Considering that torpedoes and DCs are designed to explode under water (where there isn't a lot of free oxygen), it seems to me that the explosive itself must contain the more than enough oxygen to support the explosion.  Therefore, it's debatable whether extra oxygen  in the area from a ruptured torpedo oxygen bottle (as opposed to extra oxygen in the explosive itself) would make the warhead more dangerous or the explosion of the warhead that much worse.

What the oxygen would possibly do is make any secondary fires started by the warhead explosion worse, and if the oxygen bottle ruptured first, the concentrated oxygen could obviously start fires (with an ignition source, which aren't hard to find in combat).

Do they actually explode underwater or do they first penetrate the hull and then detonate (seems that they would have a time delayed fuse like an iron bomb). On the other hand, some are designed to explode under water from magnetic proximity fuses, so they either have an explosive that does not require a great deal of oxygen, or there is a lot of dead airspace in the warhead to provide the needed oxygen.

quote:

They explode via contact or magnetic trigger

quote:

ORIGINAL: mdiehl

quote:

They explode via contact or magnetic trigger

Think you meant barometric trigger or something. Pressure triggered, not magnetically triggered. Magnetic trigger sounds good until you remember you fire it from a steel-hulled ship.

I don't recall any DCs with contact triggers. IIRC the only ASW weapons with contact triggers were torpedoes and ahead-thrown rounds like mousetrap and hedgehog.

quote:

ORIGINAL: Ryvan

quote:

ORIGINAL: mdiehl

quote:

They explode via contact or magnetic trigger

Think you meant barometric trigger or something. Pressure triggered, not magnetically triggered. Magnetic trigger sounds good until you remember you fire it from a steel-hulled ship.

I don't recall any DCs with contact triggers. IIRC the only ASW weapons with contact triggers were torpedoes and ahead-thrown rounds like mousetrap and hedgehog.

Nope. Typical torpedoes in WW2 were magnetically triggered.

Here is the Mark 6 trigger for the Mark 14 torp.



edit: Note the "delay device"

quote:

ORIGINAL: mdiehl

quote:

That was the hazzard fueling them, not once fueled, anyway Oxgen is not an issue on the open deck of a ship as it is not a confined space any fire will get plenty of Oxygen and cant be starved. The 2-3 tons of fuel *5-6 does make a pretty big fire whether you have Oxygen or not.

1) No one disputes that an intact torp on an undamaged ship is stable. We're talking, however, about torps that are damaged and exposed to intense heat. So, it wasn't "only when fueling" when the danger was present. It was also present when any Japanese oxy catalyzed torp was exposed to heat. The hazard became extreme when the fuel tank might be ruptured by damage or thermal expansion, because aerosolized fuel meeting pure O2 *is* always a way to explode something real good. 2) There's a cosmos of difference between a fuel spill burning on *air* and a fuel spill that gets a dose of pure O2. The claim that any fuel fire or fire near an warhead full of explosives is no more dangerous when exposed to a jet of bottled O2 than it is when exposed to air is just flat out wrong. Anything exposed to pure O2 burns MUCH hotter.

Yeah, a fuel fire is dangerous. And when that fire cracked an O2 bottle on a Type 93, it was on at least four occasions lethal to the IJN ship carrying the torpedo.