Torpedo failures - weather related.

[GJO]

Originally Posted by BigWalleye

!

I am sorry if have caused offence - but you asked what my technique was and I explained it in as few words as made sense.
Perhaps I am stating the obvious but it is very simple and it works.

The only drawback is that it is better not to be too close when a ship explodes (I recently had my boat lose significant hull integrity through this) and, in the later war years when the target is armed, surface attacks are impossible so the technique only works if the target speed can be matched while submerged - and, unless visibility is very poor, it is necessary to keep the periscope down and use the hydrophones for positioning until the last few seconds before firing.

BTW I have read through the theses by David Haversham Wright and it appears to agree with my stance that weather and wave height was not the problem. This had been the initial reaction by Dönitz but it was subsequently proved not to be the case.

[banryu79]

Originally Posted by GJO

BTW I have read through the theses by David Haversham Wright and it appears to agree with my stance that weather and wave height was not the problem. This had been the initial reaction by Dönitz but it was subsequently proved not to be the case.

I have not read it all, I'm at page 78 out of 200.
But even at this point, I feel myself so lucky and blessed and experiencing a (too) easy life in the face of the incredible torpedo failures documented there expecially for the first months of war (I'm currently finishing my first patrol, October 1939).

[BigWalleye]

Originally Posted by GJO

I am sorry if have caused offence - but you asked what my technique was and I explained it in as few words as made sense.
Perhaps I am stating the obvious but it is very simple and it works.

The only drawback is that it is better not to be too close when a ship explodes (I recently had my boat lose significant hull integrity through this) and, in the later war years when the target is armed, surface attacks are impossible so the technique only works if the target speed can be matched while submerged - and, unless visibility is very poor, it is necessary to keep the periscope down and use the hydrophones for positioning until the last few seconds before firing.

BTW I have read through the theses by David Haversham Wright and it appears to agree with my stance that weather and wave height was not the problem. This had been the initial reaction by Dönitz but it was subsequently proved not to be the case.

I was hardly offended. I was just in awe of your chutzpah. And a bit bemused that your thread began as a critique of the historical accuracy of h.sie's Torpedo Failure Fix.

[Friscobay]

I sometimes wondered what SH3 AI did for the 1940 post-Norway improvement of the G7e. I notice that in rough waters after Bergen goes ''blue'', I experience fewer problems with the eels. Perhaps coincidental, but the challenges with contact detonation and depth appear to slacken. However, in granting that Doenitz struggled with problems of the G7 being set too deep [ due to shore pre-settings at normal 14.7 PSI atmospheric instead of the greater pressures within a submerged U-boat whereupon depth sensors were impacted usually at a ''false deeper depth'' ], I considered, and used, settings at shallower depth in rough seas against larger C2-3 targets within 900 meters at the T and sent them to Davy Jones without other incident.

Or maybe I was just lucky.. The war drags on outside the BF grid on a calm summer day in waters still enough to fish in.

[GJO]

Originally Posted by BigWalleye

I was hardly offended. I was just in awe of your chutzpah. And a bit bemused that your thread began as a critique of the historical accuracy of h.sie's Torpedo Failure Fix.

The 'getting up close' technique is realistic and was clearly employed in real life by the most daring commanders of the early war years. Eye witness reports from merchant seamen who had survived a torpedo attack include reports of periscope spotted and even U Boats surfacing on a parallel course at a range of 200 yards. I am currently working with two volunteers who have tales to tell - one, as a child, was a survivor of the Dutch steamship Bodegraven that was sunk by U-547 in July 1944 - the other joined the Merchant Navy at the age of 16 in 1947 and served his apprenticeship with a Chief Engineer who had been torpedoed twice and gave very graphical descriptions that have stuck firmly in his memory for the last 67 years - both men have thoroughly researched aspects of the U-Boat War by talking to former Royal Navy and merchant seaman who were involved. The term "audacious" crops up frequently when they describe the attitude of U-Boat Commanders. As an example, both quote many incidences of a U-Boat surfacing alongside a sinking ship or among survivors in lifeboats so that the U-Boat Commander could ascertain the name and home port of the ship that had been sunk - something that is not mentioned in the books by Werner and Kretschmer!

[BigWalleye]

Clearly, you have found sources which lead you to have a different view of U-boat tactics than many others, including historians and men who were there and did the things we are discussing. It is interesting to read your comments. Enjoy your game!

[GJO]

Originally Posted by BigWalleye

Clearly, you have found sources which lead you to have a different view of U-boat tactics than many others, including historians and men who were there and did the things we are discussing. It is interesting to read your comments. Enjoy your game!

Yes I do enjoy the game very much and I also enjoy the expert advice that can be found on this forum. Nevertheless, I do like to be clear about historical accuracy. If I have said something that is incorrect, I would welcome evidence to that effect. I am new to the game and to this forum and have made time to research available information. I started this thread after trying to find evidence of torpedo failures due to wave height in the North Atlantic - I tried to compare the incidence of ships sunk with contemporary weather reports and the evidence seems to indicate that successful attacks occurred in almost all weather conditions apart from the most severe gales.

[BigWalleye]

Originally Posted by GJO

Yes I do enjoy the game very much and I also enjoy the expert advice that can be found on this forum. Nevertheless, I do like to be clear about historical accuracy. If I have said something that is incorrect, I would welcome evidence to that effect. I am new to the game and to this forum and have made time to research available information. I started this thread after trying to find evidence of torpedo failures due to wave height in the North Atlantic - I tried to compare the incidence of ships sunk with contemporary weather reports and the evidence seems to indicate that successful attacks occurred in almost all weather conditions apart from the most severe gales.

If your research has led you to believe that the attack tactic you described above is in some way historically representative, that's OK with me. I would not attempt to dissuade you. We all play the game the way we like.

Good luck and good hunting!

[Friscobay]

Originally Posted by GJO

The 'getting up close' technique is realistic and was clearly employed in real life by the most daring commanders of the early war years. Eye witness reports from merchant seamen who had survived a torpedo attack include reports of periscope spotted and even U Boats surfacing on a parallel course at a range of 200 yards. I am currently working with two volunteers who have tales to tell - one, as a child, was a survivor of the Dutch steamship Bodegraven that was sunk by U-547 in July 1944 - the other joined the Merchant Navy at the age of 16 in 1947 and served his apprenticeship with a Chief Engineer who had been torpedoed twice and gave very graphical descriptions that have stuck firmly in his memory for the last 67 years - both men have thoroughly researched aspects of the U-Boat War by talking to former Royal Navy and merchant seaman who were involved. The term "audacious" crops up frequently when they describe the attitude of U-Boat Commanders. As an example, both quote many incidences of a U-Boat surfacing alongside a sinking ship or among survivors in lifeboats so that the U-Boat Commander could ascertain the name and home port of the ship that had been sunk - something that is not mentioned in the books by Werner and Kretschmer!

This is a factual reading. At times, I believe that there is collision between ''gaming'' and ''historical'' aspects of SUBSIM. I am positively NO expert on the epic SH series and have experienced some of my greatest pleasure in simulations by my often-stumbling and evolving mastery of the TDC and the environment of the world in which I move . The full credit for devotion to the realism aspects of this series goes nearly solely, if not exclusively, to the hard work of those who are right here at SUBSIM.
I can however, claim to have gotten drunk with Erich Topp a long time ago when gamers were pushing little pieces of hard cardboard across a vinyl map surface where dice were rolled or counters spun in order to determine the ''music of chance'' which in turn, made the rules on whether you made it back to Lorient, or plowed mud at the bottom of the Atlantic back when Steve Jobs and Bill Gates were totally unknown to anyone other than themselves and a few college pals.
Thus in reading the historical record, we find [ never mind even Topp, who readily acknowledged getting his Red Devil in as close as fate or skill would allow ], that the drivers of U-boats and their victims, would play their deadly games at as little as a few hundreds of yards, between hunter and prey.


Heres some of the action between ships of the famous SC 42 and U-652 skippered by Oberleutnant zur-See Georg Werner Franz on the night of Sept. 09,1941 at approximately 2210 Hours.

'' Franz was stealthily overtaking the convoy on the surface from the starboard quarter. Carefully matching the ships alteration of course to-port, Franz entered between columns 7 and 8 when the submarine was seen by lookouts aboard KNOLL and PLM 13.

The range was only 300 yards''.......................

OK , so we understand that to win close, you must get close. Hell, even I haven't closed to this range yet before any convoy, Taffy, or lone wolf in either SH 3 or 4.

Damn the Torpedoes, as they say..................

[Warren Peace]

Originally Posted by BL!TZKR!EG

I just added this to my list of documents on the server. Have you got more?

As of this point, no, at least none that haven't already been mentioned and/or discussed to death in previous threads. If I happen across any more gems, I'll be certain to bring them to the community's attention.

I'm glad you all have been enjoying that thesis as much as I did, it really is a great insight into what kind of crap the Kaleuns had to deal with during the early years (I feel especially bad for Zahn. A type II having a perfect shot on the Nelson, only to be screwed because of faulty torpedoes, small surprise he was mentally broken for awhile).

[GJO]

Originally Posted by Friscobay

>Content snipped for brevity<
Heres some of the action between ships of the famous SC 42 and U-652 skippered by Oberleutnant zur-See Georg Werner Franz on the night of Sept. 09,1941 at approximately 2210 Hours.

'' Franz was stealthily overtaking the convoy on the surface from the starboard quarter. Carefully matching the ships alteration of course to-port, Franz entered between columns 7 and 8 when the submarine was seen by lookouts aboard KNOLL and PLM 13.

The range was only 300 yards''.......................

OK , so we understand that to win close, you must get close. Hell, even I haven't closed to this range yet before any convoy, Taffy, or lone wolf in either SH 3 or 4.

Damn the Torpedoes, as they say..................

Thank you for confirming what my historical research is suggesting. To be clear, I believe that poor visibility was the U-Boat Commander's friend - and tactics were developed to take advantage of the natural stealth that his boat enjoyed in such conditions. Getting in close was risky and demanded nerves of steel as well as courage and determination.

[banryu79]

Hey, GJO if you red the paper link by Warren Peace, about your previous remark that surely they did design the right way... I just came across this passage:

... In the meantime, while Dönitz awaited the committee’s findings, Dr. Cornelius and his AGC had been hard at work carrying out intensive tests of the impact pistol. The results, which were presented on May 1, were “worse than could ever have been suspected.” Not only was it proved that the AZ pistol was susceptible to a high percentage of failures as a result of the premature release of the firing pin, a fact which Cornelius attributed to its poor and overly complex design, but apparently the pistol had been cleared in peacetime as ready for front-line use after passing a “proving trial” which consisted of only two partially successful shots! “A method of working
such as this,” Dönitz wrote, “can only be regarded as criminal.”

RL tests, go figure RL design!

Btw, very intresting thread, thanks to all for the info shared here

[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).

[Iron Budokan]

Originally Posted by GJO

Although many of us think of the breaking waves that we may see at the sea shore or in shallow water, the long rollers of the North Atlantic are quite different. Here the length of the trough between wave crests may be more than sufficient to enable a torpedo to keep to a constant depth below the surface whilst following the shape of the wave - this would be especially true if the advice provided at Torpedo School was followed regarding positioning to enable the weapon to be fired at approximately 90 degrees to the wave direction.

ETA: In heavy seas, merchant ships (especially in the days of sail or steam) would choose to head into or away from waves rather than take them broadside on. Therefore, a torpedo fired at 90 AOB would be fired along the waves rather than against them.

This is interesting information, thank you!