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View Full Version : Allied VS. Japanese Torpedo Technology



LuckyBoy1
10-03-2004, 10:50 AM
Don't laugh, but believe it or not, the torpedo has, is now, and always will be a high tech weapon system in of itself. One of the best kept secrets during WWII was how Allied troops went to their deaths trying to put torpedoes on target that were either known to be defective or completely, or almost completely untested.

I would tend to think asking for a representiation of relative service reliability in the game would be asking too much and even if they wanted to, I'm not sure how you would do this because the very same planes carrying the very same, but fixed torpedoes flew as well to devastating affect on the enemy.

Still, with all the silly talk about "full real" you'd think folks would be interested in having reliability factors put back in the game. Yes, at one time we had them. The closest thing I get now to a reliability factor is an occasional false first try at starting a 109 on the sesert map. It always starts the second time! Not bad for an age of points in distributors and no computer sensors!

SkyChimp
10-03-2004, 11:29 AM
Well, I'd support modelling unreliability if it were confined to the actual types of torpedoes that were notoriously unreliable.

The most notorious torpedo was the US Mk14 submarine launched torpedo. However, after about mid 1943, they were among the best submarine launched torpedoes in the world.

The Mk13 aerial torpedo was known to malfunction or be otherwise unreliable (but not close to the extent of the Mk14), but again that was fixed in 1943 and it, too, ended the war as one of the finest aerial torpedoes in service with any nation.

The Mk15 21" destroyer launched torpedo was a good torpedo from day-one, being even better at the end of the war.

Presumably, the only one that would interest us would be the Mk13 aerial torpedo.

So, how do you model the fair reliability of the pre-1943 Mk13, and the fine reliability of the post 1943 Mk13? If that could actually be done, I'd certainly support it. But I don't think it can.

The biggest problem for aerial torpedos, far above the issue was relaibility, was hitting with them.

Ruy Horta
10-03-2004, 12:26 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by SkyChimp:
So, how do you model the fair reliability of the pre-1943 Mk13, and the fine reliability of the post 1943 Mk13? If that could actually be done, I'd certainly support it. But I don't think it can. <HR></BLOCKQUOTE>

I think some of the answer lies not with modeling a random factor of failure, but more strict limitations on proper use.

Fly a little to fast, it doesn't work
Fly a little to high, it doesn't work...

You get the picture.

To draw a parallel. We have certain experimental a/c in FB/AEP, yet the only birds with a really strict engine regime are the jets, whereas the I-185 can do amazing things with an engine that was demanding.

Although I personally would favor some kind of tweakable random failure system in all levels of this game, it would generally be a can of worms.

The alternative is sticking to conservative parameters of a weapon system, as with this example of a Torpedo, get outside the envelope, ruin your chances of a successfull deployment.

Reliable weapons could have a small "fudge" factor, unreliable ones a none at all. You might even be able to change this "setting" as the weapon matures.

LuckyBoy1
10-03-2004, 01:10 PM
I fingered a way!... maybe You can have two weapons to choose from. The reliable one or the unreliable one on earlier airplanes. I guess you could make a coop where at least the AI planes could be set to carry the one with the failure factor... would this work?

Fritzofn
10-03-2004, 01:27 PM
Axis had some nifty ideas, they had the accustic torpedo, designe to go after the propeller and engine sounds, didnt take long for the allies to make countermessures for it,

i belive the Axis also was developing a wireguided torpedo, i know they had an airial wireguided torpedo, the Fritz X, it sank a destroyer during D-day landings.

havent read so mutch about the Japanese torpedoes, so i'm not so into them, i do know they sank the ship that brought the A-bomb to it's "pitstop" in the final days before the drop...

k5054
10-03-2004, 04:51 PM
Japanese ship-launched torps were the very best, having range, speed and explosive content far in excess of allied torps. Allied navies were unaware of this at first, resulting in severe tactical inferiority.

The Allies did have an acoustic homing torpedo, used by Libs and TBMs against U-boats. It was kept secret even from U-boat survivors so no counter-measures were ever introduced by the KM.

Does anybody here REALLY want to fly missions in a TBD with a realistically duff torpedo? Fly all that way through flak and Zeroes to see your fish go belly-up? I'll be in the SBD watching from 10,000ft.

Fliger747
10-03-2004, 07:32 PM
Indeed Japanese torpedos were excellent in range and destructive power. The destroyer 'long lance' was one of the most famous and effective torpedoes ever made, when combined with effective night fighting tactics. The range of these torpedos was due to the use of OXYGEN vrs compressed air. Combined range with a large warhead made for deadly results.

The malfunctions of the US torpedoes were due to inadequate live testing in the very buget tight pre-war period. An interesting story of bureauacy at it's worst. The malfunctions were inherent in the torpedos (a bug if you will) and were not related to drop parameters etc.

American aerial torpedos were instrumental in the sinking of the super battleships Yamato and Mushashi.

Oilburner_TAW
10-03-2004, 08:10 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Fritzofn:
Axis had some nifty ideas, they had the accustic torpedo, designe to go after the propeller and engine sounds, didnt take long for the allies to make countermessures for it,

i belive the Axis also was developing a wireguided torpedo, i know they had an airial wireguided torpedo, the Fritz X, it sank a destroyer during D-day landings.

havent read so mutch about the Japanese torpedoes, so i'm not so into them, i do know they sank the ship that brought the A-bomb to it's "pitstop" in the final days before the drop... <HR></BLOCKQUOTE> Actually Great Britain and US were also working on acoustic torpedos (all kept it a secret from each other). All sides were using them by '44. Just happened to catch a show the other day about the invention/development of the torpedo on the History Channel.

horseback
10-04-2004, 04:12 PM
I vote for RuyHorta's suggestion; RL air dropped torps required a very specific delivery regime. Airspeed, altitude, arming all had to be gotten just right, never mind getting your distance and lead right, all while under heavy AAA fire.

Japanese aerial torps were more forgiving than US designs initially, but torpedo pilots of both sides had to be very, very good to be effective. Given the results in the early war, IJN pilots appear to have had the qualitative advantage in this specialty.

cheers

horseback

grist
10-04-2004, 04:42 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Oilburner_TAW:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Fritzofn:
Axis had some nifty ideas, they had the accustic torpedo, designe to go after the propeller and engine sounds, didnt take long for the allies to make countermessures for it,

i belive the Axis also was developing a wireguided torpedo, i know they had an airial wireguided torpedo, the Fritz X, it sank a destroyer during D-day landings.

havent read so mutch about the Japanese torpedoes, so i'm not so into them, i do know they sank the ship that brought the A-bomb to it's "pitstop" in the final days before the drop... <HR></BLOCKQUOTE> Actually Great Britain and US were also working on acoustic torpedos (all kept it a secret from each other). All sides were using them by '44. Just happened to catch a show the other day about the invention/development of the torpedo on the History Channel. <HR></BLOCKQUOTE>

Mk 24 "FIDO" Air-Dropped ASW Homing Torpedo
The primary aspect of U.S. World War II torpedo development, apart from copying electric torpedoes, was the design of a air-launched homing torpedo, fast enough to catch a submerged submarine, yet slow enough to enable the torpedo to hear the noise of a submarine over the flow noise created by itself. 12 knots was thought to be perfect.

Work by General Electric, Harvard and Bell Laboratories, begun in 1941 led to the Mk 24 "mine", a designation maybe due to security necessities, which carried a 42kg Torpex charge, enough for the expected impact detonation. The torpedo could run for up to fifteen minutes, yet most hits were scored directly after the submarine's dive.

The main weapons carry within the Navy were the TBF Avenger and PBY Catalina, which employed the weapon in lieu of and supporting depth charges. The first victim of the new weapon was U-467, sunk by a plane of VP-84 in the Atlantic, May 25th, 1943. Following her would be 31 boats, with another 15 damaged. (Numbers for the U.S. Atlantic Fleet only, no figures found for Pacific drops. Likely none were executed. Weapon is included for the sake of completeness and the possibility that it actually WAS used.).FIDO could be dropped at 125 knots from 250 feet. FIDO homed via four hydrophones and a simple steering mechanism pointing the torpedo toward the source of the noise.
Typical mission profiles included forcing the submarine to dive, then drop the torpedo onto its head.


Stats Year of Construction: 1942
Bore: 483mm
Weight: 308 kg / 680 lbs
Length: 2134mm / 7ft 0in
Range: 3660 m / 4000 yds at 12 knots
Explosive Charge: 42 kg / 92 lbs Torpex


http://www.microworks.net/pacific/armament/mk24fido_air.htm

grist
10-04-2004, 04:47 PM
Mk 27 Submarine-Fired Anti-Ship Homing Torpedo
The Mk 27 was a development of the airborne Mk 24, using guide rails to fit the torpedo tubes of the submarines. It was to be used passively, without use of any means of detection beyond passive sonar, against Japanese convoy escorts, from the rear tubes to put the risk of it striking the launching submarine. It would swim out of a flooded tube in order not to confuse it through the sound of compressed air swooshing around it. It was extremely successful. Used in the last month of 1944 and onwards, it destroyed 24 escorts and damaged nine, with 106 torpedos expended. This success convinced the USN of the usefullness of the new concept (which had already been tried, successfully, by the Germans, though Allied countermeasures made it more difficult in the Atlantic), and the discarded fleet submarine project of 1945 carried two external torpedo tubes specifically for the anti-escort torpedo.
The Mk 27 was used postwar until replaced by Mk 37.

http://www.microworks.net/pacific/armament/mk27_submarine.htm

Aaron_GT
10-05-2004, 02:45 PM
A bizzare piece of US torpedo trivia is that Hedy Lamarr (with help from a pianist AFAIK) devised a timing system for the explosive warhead of torpedos.

I did a quick google to find a link everyone could read:

http://www.inventions.org/culture/female/lamarr.html

Tater-SW-
10-05-2004, 06:04 PM
The drop parameters are critical in a number of ways. Drop height and speed not only affects the torpedo by possible damage to it. The higher it is dropped from (and to some extent the speed) the deeper it will go before it comes back up to running depth.

You want to get close to maximize the chances of hitting, but if you drop too close, the fish will fail to come up to a depth where it can hit the target, and will instead pass harmlessly underneath. This actually happened with a japanese torp dropped at the Lexington at Coral Sea.

In short, to be decently realistic, they need a max alt/speed for the torp to function without being damaged, and minimum range at which they won't work due to not being armed, or being too deep post-drop. The parameters simplied are: being at max drop speed or less, max drop alt or less, and no farther than X yards from the impact point (I'm not sure what the min range is, frankly, sounds like a few hundred yards, though).

tater

VF15_Muto
10-05-2004, 10:46 PM
Tater,

You forgot to mention the importance of attitude and yaw in dropping the fish so it ran straight to target .... if there was a crosswind along your axis of approach to target, the plane would be 'yawing' into target due to the weathervane effect of the wind on the tail, a situation the torpedo pilot had to correct and stabilize before releasing his fish to ensure it ran true.

And if you had a tailwind, you had to make sure your Indicated Airspeed and True Airspeed correctly factored in the wind effect on ground speed, so that you did not drop your torpedo at too high a groundspeed which could damage the fins and/or prop of the torpedo when it hit the water (or run too deep as you mentioned).

Both factors above were unkown before making a target run because torpedo pilots never knew from which way they would be making their runs until they reached the target area, and even then often had to make adjustments on the fly.

Torpedo attacks were highly sophisticated, challenging techniques requiring skill, nerves of absolute steel, on-the-fly mathematical aptitude, and hours and hours of training and experience to pull off successfully. It is no wonder that most of Japan's best aviators were torpedo bomber pilots.

S~!
VF15_Muto

ImpStarDuece
10-06-2004, 12:55 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Fritzofn:
Axis had some nifty ideas, they had the accustic torpedo, designe to go after the propeller and engine sounds, didnt take long for the allies to make countermessures for it,

i belive the Axis also was developing a wireguided torpedo, i know they had an airial wireguided torpedo, the Fritz X, it sank a destroyer during D-day landings.

havent read so mutch about the Japanese torpedoes, so i'm not so into them, i do know they sank the ship that brought the A-bomb to it's "pitstop" in the final days before the drop... <HR></BLOCKQUOTE>

The Fritz X was a radio guided cruise bomb weighing about 1000 kg. Wire guidance was used late in the war to prevent Allied jamming of the bomb. It WAS NOT used on D-Day and it was a bomb not a torpedo. The most notable success for the Fritz X was the sinking of the Italian battleship ROMA in the MEd in late 1943.

The only destroyer sank on D-Day was the Norweigan destroyer SVENNER which was sunk when German Torpedo boats launched a spread (18 torps IIRC) into the invasion fleet. There were incredibly few sorties launched by the LW in France on D-Day. Allied intellignece put it in the region of 50-70 total sorties.