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Autor Thema: Japanese homing torpedoes  (Gelesen 7358 mal)

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Offline Leandros

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Japanese homing torpedoes
« am: 04 Oktober 2013, 01:32:13 »

In his book "Japanese Destroyer Captain" Capt. Hameichi Hara mentions a homing torpedo for use by destroyers and cruisers. Anybody have a good reference to this? According to him the cruiser he commanded when covering "Yamato" on its last mission had a full load of homing torpedoes. Hara was a torpedo exepert.

Fred
www.fredleander.com - a book on Unternehmen Seelöwe - Operation Sea Lion

Jong

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Re: Japanese homing torpedoes
« Antwort #1 am: 04 Oktober 2013, 13:27:15 »

In his book "Japanese Destroyer Captain" Capt. Hameichi Hara mentions a homing torpedo for use by destroyers and cruisers. Anybody have a good reference to this? According to him the cruiser he commanded when covering "Yamato" on its last mission had a full load of homing torpedoes. Hara was a torpedo exepert.

Fred

There is no other source than the story of homing torpedos on the Yahagi in Tameichi Haras book.
By the way it makes no sense having homing torpedos on a cruiser.

In principle I see no reason why the Japanese could not have either developed a usable homing torpedo guidance system on their own or acquired one with German assistance. But - why would such torpedos be on a cruiser? Homing torpedos of WWII, whether German or American, were low speed affairs designed to attack low speed targets, either a submerged submarine or a slow moving merchant ship. At high speed homing capability would be masked by torpedo's self-noise. In 1944/45 it would be far fetched to imagine Japanese cruisers making surface attacks against slow moving American convoys. I can't believe that cruisers would be used to hunt submerged submarines. So why would cruisers have homing torpedos?

regards
Jong

Jong

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Re: Japanese homing torpedoes
« Antwort #2 am: 04 Oktober 2013, 14:42:21 »
Informations about japanese experiments with homing torpedos you can find in USNTMJ O-O1-1, page 290.
(REPORTS OF THE U. S. NAVAL TECHNICAL MISSION TO JAPAN)

It seems that only electrically driven torpedoes (Type 92 - diameter 533 mm) were used for experiments.
Yahagi had 8 × 610 mm torpedo tubes (4x2) for use of Type 93 torpedo (Long Lance).

regards
Jong


Offline t-geronimo

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Gruß, Thorsten

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Offline kgvm

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Re: Japanese homing torpedoes
« Antwort #4 am: 04 Oktober 2013, 19:41:08 »
"Homing torpedos of WWII, whether German or American, were low speed affairs designed to attack low speed targets"  :?
At least the German T 5 (Zaunkönig) was intended to be used against escorts including destroyers, not really a low speed target!

Offline Spee

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Re: Japanese homing torpedoes
« Antwort #5 am: 05 Oktober 2013, 10:40:33 »
@kgvm,

einen Zerstörer jenseits der 20kn mit einem T5 zu treffen war eine eher unlösbare Aufgabe. Die geringe Eigengeschwindigkeit von 24kn ist wirklich nur etwas gegen "low speed targets".
Servus

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Offline t-geronimo

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Re: Japanese homing torpedoes
« Antwort #6 am: 05 Oktober 2013, 12:36:18 »
War es nicht auch eher gedacht, suchende Geleitschiffe damit zu attackieren, die nicht unbedingt mit 20 kn und mehr durchs Meer pflügen?
Und die Flowers und andere Eskorten, die kleiner als ein Zerstörer waren, kamen ja nicht mal auf 20 kn.
Gruß, Thorsten

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Offline kgvm

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Re: Japanese homing torpedoes
« Antwort #7 am: 05 Oktober 2013, 12:40:55 »
Gut, Zerstörer mit voller Fahrt angreifen war sicher problematisch, aber 15 bis 20 kn sind meiner Ansicht nach keine "low speed targets".

Jong

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Re: Japanese homing torpedoes
« Antwort #8 am: 05 Oktober 2013, 13:30:19 »
:?
At least the German T 5 (Zaunkönig) was intended to be used against escorts including destroyers, not really a low speed target!

Rössler "Die Torpedos der deutschen U-Boote" S.133ff
Einsatz Zaunkönig -->Fahrstufenspanne Gegner 8 - 14 kn sind für mich schon "low speed targets"


Zitat
Gut, Zerstörer mit voller Fahrt angreifen war sicher problematisch
Das war unmöglich und dafür war der Zaunkönig auch nicht konzipiert.

Gruß
Jong

Offline Leandros

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Re: Japanese homing torpedoes
« Antwort #9 am: 10 Oktober 2013, 02:45:29 »
There is no other source than the story of homing torpedos on the Yahagi in Tameichi Haras book.
By the way it makes no sense having homing torpedos on a cruiser.

In principle I see no reason why the Japanese could not have either developed a usable homing torpedo guidance system on their own or acquired one with German assistance. But - why would such torpedos be on a cruiser? Homing torpedos of WWII, whether German or American, were low speed affairs designed to attack low speed targets, either a submerged submarine or a slow moving merchant ship. At high speed homing capability would be masked by torpedo's self-noise. In 1944/45 it would be far fetched to imagine Japanese cruisers making surface attacks against slow moving American convoys. I can't believe that cruisers would be used to hunt submerged submarines. So why would cruisers have homing torpedos?

regards
Jong

Interesting subject. Firstly, the posters here are referring mainly to German torpedo concepts - Japanese torpedo philosophy was somewhat different (as was the Italian and British). That said, that homing torpedoes were meant for slow-moving targets is not my impression but rather that their targets needed to have a minimum speed for the homing torpedoes to "lock on". As I understand it the "Zaunkönig" had a speed in excess of 20 knots.

Also, the German reason for the continuing development of the homing torpedo was to counter the increased Allied escort forces, not the merchants as such.

There was some interchange of information between German and Japanese torpedo specialists. Lauck describes this in his book: Der Lufttorpedo. He also describes the problems of inherent torpedo noise which is mainly created by reflections from the ocean surface or ground. This could be countered by correct depth setting and environmental conditions. Torpedo development also diminished this problem. Finally, even before the war was over the technological development had moved into a combination of passive and active homing technique.

Whether Yahagi had 533 or 610 mm torpedo tubes I find less interresting. Captain Hara was a torpedo specialist who already before the war had influenced on the Japanese Navy's torpedo tactics. At the end of the war he was CO of a torpedo specialist school before being assigned to Yahagi's suicide mission together with the Yamato. Before that Yahagi had been under damage repairs for a long period. If the Japanese homing torpedo experiments had been performed only with 533 (21 in.) torpedoes could the Yahagi have had such mounted for the special occasion? What do we know about that? I find it peculiar if there should be no substance in Captain Hara's mentioning of homing torpedoes.

As for homing torpedoes in cruisers, I find this quite liable under Japanese torpedo tactics. First of all, the Japanese had an excellent torpedo (Long Lance) with better range and speed than the German ones. The torpedo was the Japanese Navy's primary weapon in nightly encounters, cruisers or destroyers. Torpedoes were often fired at distances of more than 10.000 meters. One can easily imagine the advantage of a torpedo that, in the dark, can be fired in the general direction of an enemy unit, thereafter to lock on to the near-missed target. There were many examples of US ships only marginally side-stepping enemy torpedoes fired at them from ranges of up to 10.000 meters.

As for torpedo and ship's speeds, German scientists developed an apparatus that would steer the torpedo towards an expected impact point, avoiding the prolonged dog-leg swerving of the homing torpedo. This would, for a large part, compensate for deficiencies in torpedo speed if combat was given on paralell or decreasing lines.

Fred
www.fredleander.com - a book on Unternehmen Seelöwe - Operation Sea Lion

Offline Leandros

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Re: Japanese homing torpedoes
« Antwort #10 am: 10 Oktober 2013, 03:01:04 »
War es nicht auch eher gedacht, suchende Geleitschiffe damit zu attackieren, die nicht unbedingt mit 20 kn und mehr durchs Meer pflügen?
Und die Flowers und andere Eskorten, die kleiner als ein Zerstörer waren, kamen ja nicht mal auf 20 kn.

This is a good point but also that a tracking, observed, torpedo would pressure the escorts to operate on maximum speed under which they could not search for U-boats. The same thing with the Allied's noise generator. To tow it impeded the movement of the towing vessel, at the same time screening the sonar search.

It would be very interresting to know to what extent the German U-boat crews were trained or briefed on the tactical use of their homing topedoes. Seen from the back-bench there are some very obvious trick that could have been used.

Fred
www.fredleander.com - a book on Unternehmen Seelöwe - Operation Sea Lion

Offline chattius

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Re: Japanese homing torpedoes
« Antwort #11 am: 10 Oktober 2013, 08:58:05 »
G'moie

Auf
http://de.goldenmap.com/Torpedo_Typ_92
sind einige Infos, z.B. zwei Hydrophone jeweils 30Grad zur Achse deshalb Schlangenlinie,...  Man findet dort auch Literaturangaben.

Gruss Chattius


Jong

  • Gast
Re: Japanese homing torpedoes
« Antwort #12 am: 10 Oktober 2013, 19:05:13 »

Whether Yahagi had 533 or 610 mm torpedo tubes I find less interresting. Captain Hara was a torpedo specialist who already before the war had influenced on the Japanese Navy's torpedo tactics. At the end of the war he was CO of a torpedo specialist school before being assigned to Yahagi's suicide mission together with the Yamato. Before that Yahagi had been under damage repairs for a long period. If the Japanese homing torpedo experiments had been performed only with 533 (21 in.) torpedoes could the Yahagi have had such mounted for the special occasion? What do we know about that? I find it peculiar if there should be no substance in Captain Hara's mentioning of homing torpedoes.

Yahagi hatte 8 x 61cm Type 92 Torpedorohre in zwei Vierfachstartern an Bord ( bitte jetzt nicht durch die Type 92 Bezeichnung der Starter verwirren lassen ) für die 61 cm (24") Type 93 Torpedos ( von Morison als Long Lance bekannt gemacht ) Ein Wechsel auf 53,3 cm Torpedos ist nicht erfolgt und macht auch keinerlei Sinn ( siehe Lacroix ab Seite 558, Seite 571, Seite 597 ff. )

Hara war ein Torpedotaktiker , kein Wissenschaftler der neue Technik entwickelt hat.

As for homing torpedoes in cruisers, I find this quite liable under Japanese torpedo tactics. First of all, the Japanese had an excellent torpedo (Long Lance) with better range and speed than the German ones. The torpedo was the Japanese Navy's primary weapon in nightly encounters, cruisers or destroyers. Torpedoes were often fired at distances of more than 10.000 meters. One can easily imagine the advantage of a torpedo that, in the dark, can be fired in the general direction of an enemy unit, thereafter to lock on to the near-missed target. There were many examples of US ships only marginally side-stepping enemy torpedoes fired at them from ranges of up to 10.000 meters.


Wenn Yahagi akustische Torpedos ( Homing Torpedos ) an Bord gehabt hätte ,wie hätte dann ein Einsatz selbiger ausgesehen ?
Der / die Torpedo/s werden gestartet, nach einer Sicherheitsstrecke beginnen die Hydrophone nach dem lautesten Geräusch zu suchen. Das lauteste Geräusch kommt mit Sicherheit von dem Fahrzeug ( hier Yahagi ) das die Torpedos gestartet hat. Die akustischen Torpedos werden also das eigene Fahrzeug als Ziel ausmachen und darauf eindrehen. Yahagi muss dann vor den eigenen Torpedos flüchten um nicht von ihnen versenkt zu werden...

Hara schreibt in seinem Buch auch von proximity fuses ( Annäherungszündern ) die an Bord gekommen wären. Auch dafür gibt es bis jetzt keine anderen Belege.

Gruß
Jong

Offline Leandros

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Re: Japanese homing torpedoes
« Antwort #13 am: 11 Oktober 2013, 16:57:22 »
First, for the benefit of other members here, I shall repeat the three instances when Hara mentions “homing torpedoes” in connection with Yahagi. Captain Hara was the newly-installed CO of the modern light Japanese cruiser Yahagi – so far a “lucky” ship. The occasion for the event reiterated here was that a Japanese fleet detachment, led by the battleship Yamato, was on an obvious suicide mission to Okinawa - they had not been given fuel for their return trip.

On april 7th 1945 they were attacked by large swarms of American bomber and torpedo planes. Yahagi was severely damaged and Hara, on the bridge, badly dazed by the explosions and commotion all around him. He writes:

“….I was jolted back to my duties when the torpedo room voice tube squawked my name. It was Lieutenant Commander Takeshi Kameyama requesting permission to empty the torpedo tubes. He said: ‘if they are set off it will blast everything’….’Okay, dump the fish’ I shouted. Almost at once sixteen powerful homing torpedoes slithered unarmed into the water. I thought wistfully of what damage might have been done to enemy ships by these deadly weapons we now had to waste. It was another last-minute reminder of our doom.”

Several hours later Hara, laying in the water tied up to some wreckage, contemplates:

“….all our practice and training – with homing torpedoes, proximity fuzes and radar-controlled gunfire – had been of no use in this day’s action against hundred of planes….”

The observant reader shall right away detect a peculiarity. Hara writes: “…at once sixteen powerful torpedoes slithered unarmed into the water…”

Yahagi had, or had originally, only eight torpedo tubes. I know that Japanese destroyers had torpedo reloads but it usually took 20-30 minutes to do this under ideal conditions. So how is it that sixteen torpedoes slithered into the water? Could it be that eight were fired from the ready tubes and the eight others were just dumped overboard? Or is Hara, the legendary torpedo specialist, just having a case of amnesia?

Or is it that Yahagi maybe had installed a new torpedo tube set-up in the refit period before its last mission? A force multiplier consisting of a doubling of the number of torpedo tubes and homing torpedoes with proximity fuzes?

Before this Hara describes the training period after he took over Yahagi on December 22nd, 1944:

“….But not all news was bad. New weapons and equipment for Yahagi arrived almost daily. There were proximity fuzes, homing torpedoes and, most important of all, efficient radar sets. Gun crews began to learn how to use radar-controlled gunfire. Many of these devices were still in the experimental stage, but their appearance was a sign that Japanese technology was moving forward….”

As I see it there are four reasons why my question whether Yahagi actually had homing torpedoes onboard could be seen as probable:

1.   That Captain Hara says so.

2.   That Captain Hara was a legendary destroyer torpedo specialist and recent headmaster of a Japanese Navy torpedo school. This would make him eligible as a field representative during development and testing of such a new weapon.

3.   That Yahagi had a refit before its last mission.

4.   That Captain Hara, because of point 2, was given the command of Yahagi.


Zitat
Hara war ein Torpedotaktiker , kein Wissenschaftler der neue Technik entwickelt hat.
 
See above.

Zitat
from: Leandros on 10 October 2013, 02:45:29,

As for homing torpedoes in cruisers, I find this quite liable under Japanese torpedo tactics. First of all, the Japanese had an excellent torpedo (Long Lance) with better range and speed than the German ones. The torpedo was the Japanese Navy's primary weapon in nightly encounters, cruisers or destroyers. Torpedoes were often fired at distances of more than 10.000 meters. One can easily imagine the advantage of a torpedo that, in the dark, can be fired in the general direction of an enemy unit, thereafter to lock on to the near-missed target. There were many examples of US ships only marginally side-stepping enemy torpedoes fired at them from ranges of up to 10.000 meters.

Zitat
Wenn Yahagi akustische Torpedos ( Homing Torpedos ) an Bord gehabt hätte ,wie hätte dann ein Einsatz selbiger ausgesehen ?
Der / die Torpedo/s werden gestartet, nach einer Sicherheitsstrecke beginnen die Hydrophone nach dem lautesten Geräusch zu suchen. Das lauteste Geräusch kommt mit Sicherheit von dem Fahrzeug ( hier Yahagi ) das die Torpedos gestartet hat. Die akustischen Torpedos werden also das eigene Fahrzeug als Ziel ausmachen und darauf eindrehen. Yahagi muss dann vor den eigenen Torpedos flüchten um nicht von ihnen versenkt zu werden...

I think I have explained that above. It is only a question of setting the arming distance. An example: If a torpedo is aimed at a 10.000 meter-distanced target and arming set to anything after 5.000 meter, whose noise would it lock on to?

Fred
« Letzte Änderung: 11 Oktober 2013, 17:07:44 von Leandros »
www.fredleander.com - a book on Unternehmen Seelöwe - Operation Sea Lion

Jong

  • Gast
Re: Japanese homing torpedoes
« Antwort #14 am: 14 Oktober 2013, 20:22:14 »

As I see it there are four reasons why my question whether Yahagi actually had homing torpedoes onboard could be seen as probable:

1.   That Captain Hara says so.


Möglich wäre aber auch ein Übersetzungsfehler. Das Buch ist ja nicht frei von Fehlern wie z.B.  After surviving the sinking of my destroyer ( YAHAGI ) off Okinawa in April 1945, I was assigned to the Kawatana Torpedo Boat school near Sasebo and Nagasaki. My new command was to provide training for guerrilla warfare tactics in anticipation of American landings in our homeland.

Zitat

2.   That Captain Hara was a legendary destroyer torpedo specialist and recent headmaster of a Japanese Navy torpedo school. This would make him eligible as a field representative during development and testing of such a new weapon.


Was Hara an der Kawatana Torpedo Boat school für Aufgaben hatte beschreibt er ja sehr schön in Kapitel 5 seines Buches. Ausbildung von Rekruten als Besatzung für die neu zu schaffende Torpedo Boat Waffe, auf deutsch wäre es die Schnellbootwaffe, später kam dann noch die Ausbildung von Fukuryu suicide Tauchern und Führer von Shinyo suicide boats. Die Erprobung neuer Torpedotypen zählte nicht zu seinen Aufgaben.

Zitat

3.   That Yahagi had a refit before its last mission.

Letzte Modernisierung erfolgte vom 24.11. - 18.12.44 in  Sasebo. Dies betraf aber nur die Aufstockung der  leichten 25 mm Flak von 18 auf 28 Einzelgeschütze und die radargestützte Feuerleitung. Die Torpedoarmierung wurde nicht verändert ( 2 Vierfachstarter für Typ 93 Torpedos )

Zitat

4.   That Captain Hara, because of point 2, was given the command of Yahagi.


Das Kommando erhielt er zumindest nicht wegen Punkt 2 ( Erprobung von neuen bzw. "Homing" Torpedos ).


Zitat

A force multiplier consisting of a doubling of the number of torpedo tubes and homing torpedoes with proximity fuzes?


Das ist jetzt aber kompletter Unsinn "homing torpedoes mit proximity fuzes". Mit  proximity fuzes sind Annäherungszünder für Flakgeschosse gemeint.

Gruß
Jong