Torpedo failures - weather related.

[GJO]

It is indeed all very interesting and educational. I am one of many that probably owe our very existence to those rather fortunate torpedo failures! Although it is still open to debate as to how things may have developed had the early war torpedoes been perfect.

What is not established, so far, is the impact that high waves (the typical "North Atlantic Rollers") had on torpedo failure. It is true that, in the early days, BDU blamed the weather and even the Commanders themselves but it was subsequently decided that the cause was due to criminal negligence by the Torpedo Inspectorate, design defects and poor manufacture.

From the evidence available, I think it is reasonable to believe (although I would like to see hard evidence either way) that these German torpedoes were not significantly affected by weather and wave height especially when fired at close range. Another interesting fact that has emerged is that the fastest speed setting was used only when the weapon was launched from a fast surface craft (S-Boot) and the fact that these weapons were launched into the sea at high speeds (even from aircraft) tends to defeat the argument that "hitting a wave" would automatically result in failure.

[banryu79]

Originally Posted by GJO

What is not established, so far, is the impact that high waves (the typical "North Atlantic Rollers") had on torpedo failure.

I haven't the slightest idea about how much the "wave factor" coud determine a torpedo failure (in the broadest sense: either determining a premature detonation or causing the torpedo to miss the target). The thesis linked by Warren Peace doesn't quantify this aspect.

But reading that it is clear that the main culprit of the crappy performances of early war torpedoes was the pistol (both AZ and MZ aka impact & magnetic, each one in its specific way).

Just to sum up things for readers of this thread that do not want to read the whole thesis to dig up some statistics, I report them here:

During this time from the middle of November 1939 to June 12, 1940, the Uboats had fired a total of 531 torpedoes equipped with the Pi A+B pistol. Of the 531 torpedoes a total of 440 employed the magnetic setting. Ofthese, forty-three torpedoes (9.8%) were categorized as “self-detonators.” Nine torpedoes (2.0%) were “early detonators.” Sixteen
(3.6%) were “electric detonators,” while a further thirty-three were “miss detonators” (Fehlzündungen).

Obviously this is a rather complicatedsystem of classification, and it is not necessary for the purposes of this study to knowthe exact meaning of each of these vague subcategories. What is pertinent to this study is that tallying up all the individual sub-categories together reveals a total of 101 torpedoes for 23 percent of the total torpedoes fired that spontaneously exploded without hitting either the target or another object. Any of these explosions could have been noticed by an accompanying escort vessel, alerting it to the U-boat’s location and hence jeopardizing the safety of the U-boat and its crew.

Short version:

Data about Torpedoes equipped with the Pi A+B pistol - MZ setting.
period: November 1939 to June 12, 1940
fired: 440 with magnetic setting (out of 531 total eels fired).
premature detonations: 101 (23%).

So, consider how do you would feel, as a kaleun, if every 4th eel you attempt to fire is not a weapon that you throw at your enemy but an out loud scream to every ear in your sorrounding that say: "HELLO WORLD!!!".
And here we are only counting the fishes that went Ka-boom too early, add in also the dud ones and the wrong-depth runners and I let you imagine how much the failure rate climbs...

(Btw, after June 12, 1940, Bdu ordered to fire torps with the AZ setting, and due to the recents improvements on the pistol the failure rate dropped significantly, coincidentally this time frame mark the start of the "Happy Time" and MZ detonation would not be used again until 1942).

[roadhogg]

As mentioned by Banryu79, and confirmable on Wikipedia if you type "German T2 electric torpedo" in your search bar, most of the T2's depth keeping and detonation problems were apparently solved by the end of the Norwegian campaign (June 40).

I only state this due to testing of my sphere work in rough weather against warships using a 1942 IXB.
I'm having some trouble testing the reliability of the spheres due to the seemingly excessive pre-detonation, and non exploding magnetics in 42.

So I wonder if anyone would be kind enough to tell me what files control the torpedo failure rates?
It would save me some time searching through files.
I could ( and will ) replace the T2'S with T3's for testing, but as with other elements of this game, I'd rather fix it while I'm tinkering.

[roadhogg]

Ah well, obviously not then.

[BigWalleye]

Originally Posted by roadhogg

As mentioned by Banryu79, and confirmable on Wikipedia if you type "German T2 electric torpedo" in your search bar, most of the T2's depth keeping and detonation problems were apparently solved by the end of the Norwegian campaign (June 40).

That is certainly at odds with the picture presented by Clay Blair (Hitler's U-boat War, Volume I, The Hunters, 1939-1942). According to Blair, sub commanders were still critical of torpedo performance, and Dönitz was still raising the issue with OKM in mid-1941. Blair even mentions reports of circular runs, including one that may have destroyed a boat. In June, 1941, Endrass, a Ritterkreuz holder, reported four failures out of four firings.

[Zosimus]

Personally I never use T2s. T1s can be fired from further out, go faster, and have never given me problems.

[banryu79]

Originally Posted by Zosimus

Personally I never use T2s. T1s can be fired from further out, go faster, and have never given me problems.

Even if you fire them in plain daylight, from afar (let's say from more then 2000 meters)?
Of course I'm thinking about the telltale wake of bubbles...

[Zosimus]

I haven't had any problems. Usually the target is not escorted. In those cases where the target is, the destroyers can usually figure out where you are shooting from anyway. I'm almost always broadside to the target. Those extra seconds that it takes the torpedo to hit its target let me get deeper. I usually locate the target by hydrophone, go scope up, click lock, dive, and fire. I am already on my way down before the second torpedo leaves the tube.

I use two torpedo salvos on ships in convoy and only target the biggest ships. I use the slowest speed for convoys. On ships traveling alone, I can usually use a higher speed, especially if I'm unsure about the ship's speed.