Japanese Torpedo

[Orion2012]

http://www.navweaps.com/Weapons/WTJAP_WWII.htm

Take a look at the very last one listed. If the speed is accurate on what it could have done, it would have been very hard to avoid. Judging by the fact it was jumping out of the water I'd say the speed estimates are close.

[Rockin Robbins]

OMG! 60 knots!!! They had awesome weapons and not the vision to use them. Or the trained manpower that is absolutely necessary. Typing this while updating to Intrepid Ibex Ubuntu 8.10. Try that while updating Windows!

[<Jason>]

pretty cool find i would like to see some footage of that torpedo jumping out of the water

[Admiral Von Gerlach]

The IJN had worked hard to develop good torps to overcome the restrictions of the Washington Naval Treaty, and their torps were superior in both power and speed to USN. they used the following:

Type "93" what we called the Long Lance Oxygen powered 24" torpedo was launched by surface ships both DD and CL CA, not subs.

Type "95" Mod 1 were 21 inch oxygen powered launched by subs, the Long Lance ran for 22,000 yards at 49 knots, and had 1,078 pounds of high explosive in its warhead. The shorter Type 95 was not nearly so powerful, able to travel 13,000 yards at 45 knots, with 891 pounds of explosive in its warhead. The 95's were shorter and smaller in diameter to allow handling in subs.

The Japanese worked hard on their torpedo doctrine and training, using real life conditions, in the North Pacific, and had extensive recovery and reuse of training torps...both subs and surface...while the USN had removed most torp launchers from the cruisers and neglected to train with them as much. The Japanese DD's could btw carry more reloads, often being able to reload twice.....and torps were taken very seriously and their direction was part of the gunnery control not just a poor add on.

A key factor about IJN torpedoes was as noted in this thread, the speed...ys 50 knots ....
Partly this was due to two factors...and let me quote a man who i greatly respect who knows this aspect very well, PDC Sensha...." the Oxygen torpedoes have two benefits: lack of combustion byproducts that leave a wake (most notably nitrogen; air torpedoes have less oxidizer (oxygen) and more inert gasses (nitrogen primarily) in their air flasks), and range (pure oxygen takes up less space than the same amount of oxygen as a component of air (tops of 20% by volume); more space for fuel and oxidizer. Oxygen oxidized flames also burn hotter (better combustion), so a given amount of fuel could stretch farther. All this translated out into going further faster.

I don't have the figures with me, but I think that the top speed on our torpedoes (which only allowed a very short range) was well below the lower speed on the Japanese torpedo (which allowed a range that was so great we had trouble believing that it actually could occur). At their top speed, the things zipped along near 50 knots (compared to a top ship speed of 37 knots or so) out to a distance that was greater than our "close range". Faster to the target means less time to evade, hence more accurate."

In fact the IJN torpedos were so good, and the USN so slow to accept this for far too long that they the IJN surpirsed the USN on more than one occasion and left the US commanders looking around for mines or other reasons for damage when it was the IJN fish that did the trick.

all of this was confirmed by the Naval Intelligence Misiosn to Japan after the war which makes very interesting reading.

[Orion2012]

Originally Posted by Admiral Von Gerlach

The IJN had worked hard to develop good torps to overcome the restrictions of the Washington Naval Treaty, and their torps were superior in both power and speed to USN. they used the following:

Type "93" what we called the Long Lance Oxygen powered 24" torpedo was launched by surface ships both DD and CL CA, not subs.

Type "95" Mod 1 were 21 inch oxygen powered launched by subs, the Long Lance ran for 22,000 yards at 49 knots, and had 1,078 pounds of high explosive in its warhead. The shorter Type 95 was not nearly so powerful, able to travel 13,000 yards at 45 knots, with 891 pounds of explosive in its warhead. The 95's were shorter and smaller in diameter to allow handling in subs.

The Japanese worked hard on their torpedo doctrine and training, using real life conditions, in the North Pacific, and had extensive recovery and reuse of training torps...both subs and surface...while the USN had removed most torp launchers from the cruisers and neglected to train with them as much. The Japanese DD's could btw carry more reloads, often being able to reload twice.....and torps were taken very seriously and their direction was part of the gunnery control not just a poor add on.

A key factor about IJN torpedoes was as noted in this thread, the speed...ys 50 knots ....
Partly this was due to two factors...and let me quote a man who i greatly respect who knows this aspect very well, PDC Sensha...." the Oxygen torpedoes have two benefits: lack of combustion byproducts that leave a wake (most notably nitrogen; air torpedoes have less oxidizer (oxygen) and more inert gasses (nitrogen primarily) in their air flasks), and range (pure oxygen takes up less space than the same amount of oxygen as a component of air (tops of 20% by volume); more space for fuel and oxidizer. Oxygen oxidized flames also burn hotter (better combustion), so a given amount of fuel could stretch farther. All this translated out into going further faster.

I don't have the figures with me, but I think that the top speed on our torpedoes (which only allowed a very short range) was well below the lower speed on the Japanese torpedo (which allowed a range that was so great we had trouble believing that it actually could occur). At their top speed, the things zipped along near 50 knots (compared to a top ship speed of 37 knots or so) out to a distance that was greater than our "close range". Faster to the target means less time to evade, hence more accurate."

In fact the IJN torpedos were so good, and the USN so slow to accept this for far too long that they the IJN surpirsed the USN on more than one occasion and left the US commanders looking around for mines or other reasons for damage when it was the IJN fish that did the trick.

all of this was confirmed by the Naval Intelligence Misiosn to Japan after the war which makes very interesting reading.

Interesting Information. Wouldn't happen to have info on propulsion systems for IJN ships would ya??

[Task Force]

Yea, it always seems the japanease are ahead in technology (well not always, they didnt invent radar.)

[Sailor Steve]

Originally Posted by Orion2012

Judging by the fact it was jumping out of the water I'd say the speed estimates are close.

1) It doesn't say it was jumping out of the water, it said it was difficult to keep it from breaking the surface. This indicates a control problem, not excessive speed. There is still no reason why it couldn't be that fast, even in 1934.

2) The reason they didn't put it into service was likely that they could never get it to work properly. Not lack of vision - rather insurmountable problems.

[CaptHawkeye]

Of course, a disadvantage of the Japanese torpedoes is that they were extremely unsafe. Accidents in the production facilities were common, for this reason they had a slow production rate.

[Admiral Von Gerlach]

Ys have in fo on propulsion systems what did you want?

re the oxy torps ys very volatile. but they worked well and were reliable and gave the range and power needed. Innovative design was not matched by raw materials and so decisions were made, so i heard to not proceed with many things that might have helped but there just were not the resources for them.

Japanese Sub Propulsion Systems and Info ....


Submarine Propuslsion Systems of the IJN
Disel engines used by Japanese Submarines like the designes of early submarines, initally came from a variety of foreign countries. However, the more reliable diesel engines from Germany were eventually adopted by the Japanese. The various disel engines purchased by the IJN are shown in the following list:
1915 Schneider-Laubeuf, 2000 hp
1916 Vickers 600 hp
1919 Fiat-Laurent, 2,600 hp
Sulzer Type 2, single action, 2 cycle, air injection, 1,300 hp, the patent was purchased and the engine was made in Japan from 1918 to 1923 for use originally in the experimental 1051.
Sulzer Tye 3, single action, 2 cycle, air injection, 3,400 hp, this engin was build between 1923 and 1933 for use in various Kaidai-type subs.
MAN type 1 Maschinenfabrik Augsburg-Nurnberg) single action, four cycle, air injection, 1,200 hp, this engine was mae from 1925 to 1927 for use in the Kirai sen Minelaying subs
MAN Type 2 single action, four cycle, air injectin, 3,000 hp, used in several Kaiai and the early Junsen type subs.
After learning doreign diesel technology and gaining considderable experinece with diesel engines, the IJN was able to make its own diesel systems for subs. The Naval Technical Bureau (Kansei honbu) abbreviated Kanpon, took the iniitive for designing and making diesel engines for use in IJN subs. Also because of Kanpon's guidance and assistance, private machinery companies started to build sub engines. Japanese designed diesel engines were quite sophisticated for the time and had several special featuers, in cluding double aciton, non0air injection and high power in various models. some of the diesel engines originally designed and made by the Japanese are listed below. The increasing size and sophisitcation of these engines were symtomatic of other modern developments taking place in the IJN submarine force.

Kanpon Type 1a, Model 7, double action, 2 cycle, air injection, 4,500 hp, This engine was made in 1935 for the improved Junsen-type submarine.
Kanpon Type 1b, Model 8, double action, two cycle, air injection, 5,000 hp, Produced from 1933 to 1942, this engine was used in various Kaidai submarines.
Kanpon Type 1a, MOdel 10, double action, two cycle, air injeciton, 6,300 hp. this engine was made from 1936-1938 for the Junsen Submarines.
Kanpon Type 2, Model 10, double action two cycle, air injection, 7,000 hp. this engine for the large Junsen submarines was produced between 1939 and 1943.
Mitsubishi Type 21, Model 8 single action four cycle non air injection, 1, 450 hp. This engine was made in 1935 for the Kaichu submarine
Kanpon Type 22, Model 10, single action, four cycle, non air injection, 2,600 hp. This engtine was produced in 1943 to the end of the war for various submarined, but mainly for the Kaichu boats.

Electric Motors and Batteries
Japanese Submarines used a diesel-electric propulsion system. An electric genearator that coudl also be used as a motor was connected by a shaft to the aft end of each of two diesel engines. Clutches separated the engines in one compartment from the gnerator motors in the adjacent compartment. The shafts from the propellers were also connected to the generator motors with clutches. When surfaced and underway on diesel power, all clutches were engaged. Batteries could also be charged in the mode by diverting some electrical current to storage cells or by running on the surface with one diesel engine aplied to propulsion and one engaged soley for charing batteries. A similar operation was possible late in the war i those subs fitted with the snorkel device. When submerged and using battery power, the clutches between the diesel engines and genrator motors ere disengaged. If batteries were charged while a submarine weas at mooring, the clutches beteen the generator motors and the propeller shafts were disengaged.

This propulsion system was extremeely aweward, thus Japanese submarines, large I boats in particluar, were generally slow diving not only becauseof their large hulls but also because of the cumberson linkage arrangment in the propulsion system. For example, in an emergency dive requiring swift action, the engineers would first stop the egines. Then they would have to disengagte two clutches between the pairs of generator motors and the two diesel engines. An electrician would then switch th electrical circuts of the generators, thus changing their function into motors. Electricla currrent from the batteries woudl then rotate the armature of the motors and engaged clutches would continue to force the propellers to turn.
Electrical generators were direct current DC wth a low 220 volt output. There were three typs of motors, one 660 kilovolt amperes produced 900 hp for the Kaidai submarines, a second type 880 kilowavolt amperes produced 1,200 hp for the Junsen and the I-400 class submarines and the thrid type 440 kilovolt amperes produced 600 hp for the Kaichu submarines.

Batteries
Batteries were the ebonite clad type made by the Yuasa Battery Company. A group of 118 lead acid batteries generated 240 volts. The number of groups in a submarine depended on the size and power requirments of that particular class of submarine. Associated with these batteries were hyudrogen detectors and electrolytic tye ampere hour meters, in late 1945, US Navy investigators found these two Japanese Instruments to be "far superior to those observed on Germman Submarines.

for further info i can help or i recomend ...

The Japanese Submarine Force and World War II
Carl Boyd and Skihiko Yoshida Naval Institute Press.
Yaisen yomurei Navy Battle Regulations 1934
Rengo kantai sensaku Combined fleet tactical instructions, Rev Ed 1943
Sekito, Yoshimitsu. Kojutsu kiroku (oral history record 1977
Torisu Kennosuke Kojutsu kiroku Oral History Record 1977
Boejcho Boejkenshujo Senshibu Defense Ministry Defense Research Institute, WAr History Branch, Tokyo
The Imperial Japanese Navy in World War II: A Graphic presentaion of the Japanese Naval Organziation and List of Combantant
and Non Combatant Vessels lOst or Damaged in the WAr Report
Paine, Thomas O. The Transpacific Voyage of His IMperial Japanes Jajesty's Submarine I-400: Journal, July - December 1945.
US Army Military History Section, Special Staff, General Headquarters, Far East Command, The Imperial Japanese Navy in World
War II, February 1952.
US Navy Crews of I0201 and I 203 atSasebo, Kyushyu, Japan, 1946, General Information book I-200 Class Japanes Submarines
Naval HIstorical Center, Wash DC
Documents RElating to the Japanese Submarine Squadron 8 Operations, Case J, 1507, Dr. 4, Miscellaneous International Reprots.
Japanese Submarine Locations 7-10, August 1942, Washignton Doccument Center, WDC no. 161701
Log taken from Submarine I-1 sunk of Guadalcanal, Translations of Captured Japanese Doccuments, Apri.l 27, 1943, Item no. 508
(S-951)
Report of the US Naval Technical Mssion to Japan 1945 - 1946, Microfilm reels JM-200-B, G, H and I Submarine Operations, October 1944, WDC, no. 161011.
Summary of the Major Japanese Submarine Operations Case J, 1504, Dr.3, US Strategic Bombing Survey, Interrogations Japanese
Submarines.
NAVAL WAR COLLEGE, NeWPORT, RI.
Riffer, William J. A Study in Operational Failure, Japanese Submarine Operations in WWII 1989, Photocpy.

[keltos01]

good data thanks !

keltos

[Admiral Von Gerlach]

Thank you Sir, very much, i admire very much your work on boats and additions. I am very grateful to have chance to share from my study of remarkable IJN and those fine men in her. They faced great odds and never gave up and had many fine ships.

To quote two of the finest experts on the IJN that i know, Carl Boyd and Akihiko Yoshida, ...

"Submarine Technolgoy wss advanced enough by wartime standards and Japan's professional highy dedicated submariners were brave enough to do their duty. However the Allies achieve a huge superiority in numbers and forces and the attrition of war gradually wore down the IJN and the submarine force, always wedded to the interests of the battle fleet, was an eary victim
and notable sacrifice."

And US Naval Technical experts in the US Technical mission to Japan found on studying the IJN boats that the instruments and level of technology was much superior to German U boats they had also inspected.