Rodney torpedoes compared to Long Lance?

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Steve Crandell
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Re: Rodney torpedoes compared to Long Lance?

Post by Steve Crandell »

Here is a quote from the Wiki entry about the aforementioned battle:

In spite of their defeat in the battle, the Americans had prevented Tanaka from landing the desperately needed food supplies on Guadalcanal, albeit at high cost. A second Japanese supply delivery attempt by 10 destroyers led by Tanaka on December 3 successfully dumped 1,500 drums of provisions off Tassafaronga, but strafing American aircraft sank all but 310 of them the next day before they could be pulled ashore. On December 7, a third attempt by 12 destroyers was turned back by US PT boats off Cape Esperance. The next night, two US PT boats torpedoed and sank the Japanese submarine I-3 as it attempted to deliver supplies to Guadalcanal. Based on the difficulties experienced trying to deliver food to the island, the Japanese Navy informed Imamura on December 8 that they intended to stop all destroyer transportation runs to Guadalcanal immediately. After Imamura protested, the navy agreed to one more run to the island.[42]

The last attempt to deliver food to Guadalcanal by destroyers in 1942 was led by Tanaka on the night of December 11 and consisted of 11 destroyers. Five US PT boats met Tanaka off Guadalcanal and torpedoed his flagship Teruzuki, severely damaging the destroyer and injuring Tanaka. After Tanaka transferred to Naganami, Teruzuki was scuttled. Only 220 of the 1,200 drums released that night were recovered by Japanese army personnel on shore. Tanaka was subsequently relieved of command and transferred to Japan on December 29, 1942.[43]

On December 12, the Japanese Navy proposed that Guadalcanal be abandoned. Despite opposition from Japanese Army leaders, who still hoped that Guadalcanal could eventually be retaken from the Allies, on December 31, 1942 Japan's Imperial General Headquarters, with approval from the Emperor, agreed to the evacuation of all Japanese forces from the island and the establishment of a new line of defense for the Solomons on New Georgia. The Japanese evacuated their remaining forces from Guadalcanal over three nights between February 2 and February 7, 1943, conceding the hard fought campaign to the Allies. Building on their success at Guadalcanal and elsewhere, the Allies continued their campaign against Japan, ultimately culminating in Japan's defeat and the end of World War II.[44]

end quote

Now, before you complain about Wiki, I recently finished reading the very well researched "Neptune's Inferno" once again, and it's conclusions are similar. If there was no more surface engagements it was because the IJN was defeated and simply didn't try anymore. No more shellings of Henderson field, etc.

And all this in spite of the USN not having functional torpedoes.
Byron Angel
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Re: Rodney torpedoes compared to Long Lance?

Post by Byron Angel »

..... To be more precise (IMO): "All this because the US held Henderson Field."

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KevinD
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Re: Rodney torpedoes compared to Long Lance?

Post by KevinD »

alecsandros wrote:
Byron Angel wrote:The Type 93 "Long Lance" oxygen torpedo was a MUCH more powerful torpedo. Its exact specs (there were several variants) can be found on the web, but, if memory serves, the LL would travel 20,000 yards @ 50 knots while carrying a 50% heavier warhead; its maximum range at reduced speed setting was something on the order of 45-50,000 yards.

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...
As an addition: after the war, a US technical commision invetigated the use of LLs. They were surprised by the weapons capabilities, BUT also noted that: the LL were much more sensitive than normal torpedoes, and required highly skilled operators to transport them into the ship's magazines, and when in combat, to prepare and actualy launch them.

If the slightest mistake was make in their handling and preparation, they would travel erraticaly.

Late to the party, but.......................................re what I have underlined above. I was unaware of 'those' sensitivities you refer to. Do you have a link to that report? My understanding was the 'loading' of - i.e. highly compressing - the oxygen propellent that was the 'sensitive' part, but are you / the report implying that the general 'handling' of the torp itself prior to the oxygen being 'loaded/compressed' could affect its tracking (gyro settings) once in the water?
alecsandros
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Re: Rodney torpedoes compared to Long Lance?

Post by alecsandros »

KevinD wrote:
alecsandros wrote:
Byron Angel wrote:The Type 93 "Long Lance" oxygen torpedo was a MUCH more powerful torpedo. Its exact specs (there were several variants) can be found on the web, but, if memory serves, the LL would travel 20,000 yards @ 50 knots while carrying a 50% heavier warhead; its maximum range at reduced speed setting was something on the order of 45-50,000 yards.

B
...
As an addition: after the war, a US technical commision invetigated the use of LLs. They were surprised by the weapons capabilities, BUT also noted that: the LL were much more sensitive than normal torpedoes, and required highly skilled operators to transport them into the ship's magazines, and when in combat, to prepare and actualy launch them.

If the slightest mistake was make in their handling and preparation, they would travel erraticaly.

Late to the party, but.......................................re what I have underlined above. I was unaware of 'those' sensitivities you refer to. Do you have a link to that report? My understanding was the 'loading' of - i.e. highly compressing - the oxygen propellent that was the 'sensitive' part, but are you / the report implying that the general 'handling' of the torp itself prior to the oxygen being 'loaded/compressed' could affect its tracking (gyro settings) once in the water?
I don't remember exactly, but I have the feeling that yes, the torpedoes themselves had highly sensitive internal equipment, prone to failure or malfunctioning in case of (even slight) miss-handling.

the report (446 pg... 53MB) can be found here:
http://www.fischer-tropsch.org/primary_ ... 0-01-1.pdf
Garyt
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Re: Rodney torpedoes compared to Long Lance?

Post by Garyt »

Biggest negatives I see about the Long Lance was it volatility of the weapon to enemy fire.

I've often wondered if it would have been better for the Japanese Heavy Cruisers to have a less volatile if perhaps less well performing torpedo on deck as opposed to the LL.

On Destroyers and even light cruisers, I'd keep the Long Lance.

But a Long Lance on deck is in essence a magazine on deck with no protection. If one has little or no armor to protect the Magazine, OK, but if one has armor to stop 5" shells or even larger high explosive rounds, you are doing a vessel a disservice by keeping in essence an exposed magazine on deck.

Japanese Heavy cruisers had another issue leaving them vulnerable as well, they had the lightest armored MA turrets of any navy. I guess this was done to keep them from being too top heavy, but 1" turrets can be penetrated even by 5" common rounds at most ranges, which not only knocks out the turret but also creates the possibility of a flash fire getting to the magazines.

But the Long Lance on deck made any vessel carrying it a potential magazine explosion with even small to medium naval cannon fire. Granted a magazine explosion on the outside of the vessel is not as bad as an internal magazine explosion, but it still will likely cripple a vessel.
alecsandros
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Re: Rodney torpedoes compared to Long Lance?

Post by alecsandros »

Garyt wrote:
But the Long Lance on deck made any vessel carrying it a potential magazine explosion with even small to medium naval cannon fire. Granted a magazine explosion on the outside of the vessel is not as bad as an internal magazine explosion, but it still will likely cripple a vessel.
... Wasn't a heavy cruiser lost at Samar because of 5" rounds hiting the Long Lances ?
KevinD
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Re: Rodney torpedoes compared to Long Lance?

Post by KevinD »

Garyt wrote:Biggest negatives I see about the Long Lance was it volatility of the weapon to enemy fire.

I've often wondered if it would have been better for the Japanese Heavy Cruisers to have a less volatile if perhaps less well performing torpedo on deck as opposed to the LL.

On Destroyers and even light cruisers, I'd keep the Long Lance.

But a Long Lance on deck is in essence a magazine on deck with no protection. If one has little or no armor to protect the Magazine, OK, but if one has armor to stop 5" shells or even larger high explosive rounds, you are doing a vessel a disservice by keeping in essence an exposed magazine on deck.

Japanese Heavy cruisers had another issue leaving them vulnerable as well, they had the lightest armored MA turrets of any navy. I guess this was done to keep them from being too top heavy, but 1" turrets can be penetrated even by 5" common rounds at most ranges, which not only knocks out the turret but also creates the possibility of a flash fire getting to the magazines.

But the Long Lance on deck made any vessel carrying it a potential magazine explosion with even small to medium naval cannon fire. Granted a magazine explosion on the outside of the vessel is not as bad as an internal magazine explosion, but it still will likely cripple a vessel.

Any warship of any navy that had torpedoes on deck that were hit by a shell would / could have suffered a catastrophic explosion, not just the IJN. The ‘problem’ (in the situation being discussed) with the Long Lance was that it carried oxygen as propellant (and they had on-board / nearby the necessary equipment for manufacturing and storing high pressure ‘pure’ oxygen). This added dramatically to the resulting conflagration when there was an explosion of the torps.

Other than that fact (the compressed oxygen), lb for lb or kg for kg for the amount of actual explosive content in the warhead, the Long Lance shouldn’t have been any more dangerous on deck than any other nation’s torps.

Please correct me if I am wrong, and if so please contribute to my understanding of why, if the compressed oxygen was removed, the torps were more dangerous than other nations?

Edit: And thanks for the link alecsandros!
Byron Angel
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Re: Rodney torpedoes compared to Long Lance?

Post by Byron Angel »

"... the torpedoes themselves had highly sensitive internal equipment, prone to failure or malfunctioning in case of (even slight) mis-handling."

To put the above comment in perspective, the same was true of radar. But no one advocated that radar be discarded on those grounds; they just worked at providing proper service and care. At the end of the day, approximately two-thirds of the US and Allied ships lost in the Solomons campaign fell victim to torpedo attack. The Type 93 was a highly effective weapon

The risk factor related to the use of pure oxygen was (insofar as my reading has progressed on the topic) was not so much related to an outright explosive burst of the high-pressure flask as it was the piercing of same by fragments. The emitted stream of pure oxygen under high-pressure would greatly intensify any nearby fire upon which it might play.

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KevinD
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Re: Rodney torpedoes compared to Long Lance?

Post by KevinD »

Byron Angel wrote:The risk factor related to the use of pure oxygen was (insofar as my reading has progressed on the topic) was not so much related to an outright explosive burst of the high-pressure flask as it was the piercing of same by fragments. The emitted stream of pure oxygen under high-pressure would greatly intensify any nearby fire upon which it might play.
That is basically correct. Oxygen itself is not combustible on its own per se, but will dramatically increase or enlarge any fire that it is added to; by the release from a ruptured high pressure cylinder inside the torp itself or from the much larger high pressure oxygen storage 'bottles' nearby being ruptured - in the instance we are discussing. (As an example of oxygen dramatically increasing heat one only has to look at the use of oxy-acetylene for the cutting of metal.) However, the cylinders / bottles do not have be punctured to explode; a nearby fire cold heat the oxygen pressure vessels enough, both inside - and the storage bottles outside - the torps, to make them explode simply from overpressure, thus either adding dramatically to any conflagration (as I stated above), or even starting a conflagration inside the torp which in turn could then lead to the explosive warhead overheating and igniting/exploding.

Accidents could also happen when manufacturing the oxygen on-board and transferring it (under high pressure) to the oxygen holding cylinder in the torps if the high pressure oxygen came into contact with a contaminate (grease / oil for example) or some other foreign object (a 'burr' in a metal connection, etc) in the filling ‘system’, i.e. compressor, fill lines, storage bottles, etc, and hence being the cause of, or 'start' of, the fire as it were. (Believe me I know how tricky / dangerous it can be to ‘handle’ high pressure pure oxygen, having worked with / used high pressure oxygen for many many years in the scuba diving world - thankfully without personal incident - I have seen several examples of ‘oxygen fires’.)

So, I am still left wondering why, if oxygen was removed from the Long Lance equation so to speak, then why are Long Lance’s considered any more volatile than any other (IJN or other navies) torpedo? Was the explosive material the IJN used for their LL warhead particularly more volatile than any other torps for instance? Or is it just the presence of high pressure oxygen?
alecsandros
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Re: Rodney torpedoes compared to Long Lance?

Post by alecsandros »

KevinD wrote:

So, I am still left wondering why, if oxygen was removed from the Long Lance equation so to speak, then why are Long Lance’s considered any more volatile than any other (IJN or other navies) torpedo? Was the explosive material the IJN used for their LL warhead particularly more volatile than any other torps for instance? Or is it just the presence of high pressure oxygen?
... If you are reffering to my above comment about "sensitivity", I was not refering to sensitivity of the explosive charge, but of the torpedo equipment. At least this is what I remember from the report - that it took skill to load a torpedo on board, and properly launch it at the right time. [but I don't have the time to re=read the report...]
KevinD
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Re: Rodney torpedoes compared to Long Lance?

Post by KevinD »

alecsandros wrote:
KevinD wrote:

So, I am still left wondering why, if oxygen was removed from the Long Lance equation so to speak, then why are Long Lance’s considered any more volatile than any other (IJN or other navies) torpedo? Was the explosive material the IJN used for their LL warhead particularly more volatile than any other torps for instance? Or is it just the presence of high pressure oxygen?
... If you are reffering to my above comment about "sensitivity", I was not refering to sensitivity of the explosive charge, but of the torpedo equipment. At least this is what I remember from the report - that it took skill to load a torpedo on board, and properly launch it at the right time. [but I don't have the time to re=read the report...]
No, I understood what you were referring to. But my question does not refer to ANY other aspects (handling, loading, etc) of the torp, ONLY to the volatility of the explosive content / composition of the LL warhead; hence let me repeat “leaving the oxygen fuel / oxygen generating and storage facilities OUT OF THE EQUATION, was the explosive material used by the Japanese in the LL warhead any more volatile / unstable / sensitive (shall we say) than any other torpedo”? And my belief is "I dont think so". It is my understanding that it was simply the inclusion of the oxygen that made them 'more' dangerous whilst on-board, under attack, etc.
Steve Crandell
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Re: Rodney torpedoes compared to Long Lance?

Post by Steve Crandell »

That is my impression as well.
KevinD
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Re: Rodney torpedoes compared to Long Lance?

Post by KevinD »

I asked some questions elsewhere and turned up the following info from a Japanese researcher; According to the book Nihon Suirai Senshi (History of Japan´s Torpedoes- published by Rekishi Kanko Kyokai ) <日本水雷史、木俣次郎、歴史刊行会> written by professor Kimata Jiro of Tokyo University, the IJN torp research team aimed at developing an anti-induced explosion characteristic for the ‘powder’ of the Type 93 (Long Lance) so the explosive content in the warhead was less sensitive and more stable.

So, as I thought, it was the propellant fuel that was the culprit, not a warhead that was prone to ‘easily’ explode.
Byron Angel
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Re: Rodney torpedoes compared to Long Lance?

Post by Byron Angel »

The US Technical Mission report (IIRC) cited the Type 93 warhead composition as 60/40 TNT + Hexanite.

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