Recorded 28 May 194334
The second section of extracts focuses on weaponry and detection gear, both German and Allied. There were many more conversations on these and other technical matters than the few extracts reproduced here would suggest, but on the belief that most readers would not want to get caught up too much in the whirring world of machinery and electrons, only six sample conversations on technical matters are extracted here. Less concentrated on May, these conversations stretch from March to August. The favorite subject was the new zigzagging FAT torpedo.
BRÖHL [Re: FAT, or “convoy” torpedoes]: It’s quite a normal torpedo which has a setting device, so that after traveling a certain distance—
FIGHTER PILOT, F.W. 190: What distance?
BRÖHL: It varies. It’s adjustable, so that when it goes past the target it doesn’t run straight out to the end of its course and then explode, but, after passing the target, it turns round and zigzags, so there is a possibility that after passing it at first, it will still find the target. I can estimate how far away the target is. Then I say it shall be set at twenty-five hundred meters and from there the torpedo makes zigzags.
PILOT: … How many zigzags does it make?
BRÖHL: It can go on to the end of its course.
PLLOT: How far does such a torpedo run?
BRÖHL: Seventeen thousand meters.
PILOT: I presume they are electric torpedoes?
BRÖHL: Air torpedoes, too.
PLLOT: Oh, I see, they’re just ordinary torpedoes which run straight. There is this mechanism in them and that’s probably what he [Interrogation Officer] meant.
BRÖHL: It’s possible he’s talking about a different one altogether.
PILOT: The torpedo that you had on board is the “convoy” torpedo, isn’t it?
BRÖHL: Yes.
PILOT: And what does that mean?
BRÖHL: Spring mechanism (Federapparat).
PLLOT: I presume then that this spring mechanism is built into the ordinary torpedo.
BROHL: Yes.
PILOT: The spring mechanism is simply a thing which can be set, like my [Luftwaffe] automatic pilot.
BrÖh L: Technically it is rather complicated, making it so that it zigzags and so on. You can set it. For example you usually fire this torpedo at convoys, where several ships are sailing together. Assuming you fire at a particular ship, it [the torpedo] curves around, and if you fire two, three, or four of these, you can say with ninety percent certainty that one of them will hit. With a quadruple fan salvo it is certain, for three or four ships usually sail together.
PILOT: Why did you only have six of these with you?
BRÖHL: They were probably not quite ready, or perhaps they gave some to each U-boat for practice.
PILOT: How is the setting done?
BRÖHL [Draws]: … The basic idea is this: … I have a torpedo, it runs for such-and-such a time and for such-and-such a distance. If I fire at five hundred or a thousand meters, the remaining sixteen thousand meters are quite useless. So how can we make use of them somehow or other?
PILOT: Well, supposing it turns, makes a curve of 1800 when it is ready. What’s the setting then?
BROHL: I can make the setting according to my own judgment of what the position is.
PILOT: Let us assume there are three ships at a range of three thousand meters, a few hundred meters apart—you fire at the center one—
BROHL: I fire at the first ship, which is farthest ahead and lies in the most favorable position. That is three thousand meters, and I set it for thirty-five hundred, and if it goes past it begins to zigzag.
PILOT: Yes, how does it zigzag, does it come back on the same track?
BRÖHL: … It makes perfectly ordinary turns on a reciprocal course the whole time. The torpedo travels, we’ll say, one thousand meters back, that is, it travels to and fro within the area of the steamer’s course. You can set it in several different ways.
PILOT: IS it worked by a spring mechanism?
BRÖHL: That’s purely a code name. There probably is a spring in it.
PILOT: … If a torpedo goes past a ship, they think it’s all over and finished with. And then suddenly it comes back from the other side?
BRÖHL: They can’t see the track.
PILOT: Because it’s an electric torpedo; that means it can’t be an air torpedo.
BRÖHL: It can be built into the air torpedo, and then you simply fire those at night, when you can’t see the wake of the torpedoes.
PILOT: The mechanism must be pretty big, mustn’t it?
BRÖHL: It’s a sort of box, about thirty by thirty centimeters [n.8 by n.8 inches].
PILOT: It’s inside the torpedo; don’t you have to take the torpedo out of the tube to set it beforehand?
BRÖHL: It’s set by means of a pin.
PLLOT: By the Commander or by you?
BRÖHL: By me. There’s a pin which goes down into the torpedo and adjusts the setting and then drops out before the torpedo is fired. The torpedoman’s mate is responsible for the setting. I give him the data.…
PILOT: You must have to take care not to be hit by your own torpedo. BROHL: Yes.
PILOT: How do you do that?
BRÖHL:You make off at three-quarters speed either hard to starboard or hard to port.
PILOT: Immediately after you’ve fired? BROHL: Yes.
PILOT: How fast does a torpedo like that travel?
BRÖHL: It has a speed of thirty knots.…
Recorded 21 March 194335
GASSAUER: [In] the latest innovation, which is already quite old, the torpedo runs towards the target and then makes short loops. BOMBER PILOT, JU. 88: Zigzags?
GASSAUER: We’ve got that too. I can tell you all about that: we call it the FAT. That’s a very fine torpedo. You set the preliminary run, that is, you estimate or measure the distance. We’ll say the ship is two thousand meters away, so I set the preliminary run for two thousand and I can also set the torpedo to run either to the right or to the left. If I’ve got the exact range, I set the torpedo for a “short leg"; it can make either short or long zigzags. It then runs straight ahead for the two thousand, allowing for the angle of lead. And supposing it doesn’t hit, that it’s been fired too short, or too far ahead, then it begins [zigzagging] here. It runs on another three hundred meters and then turns and runs back again.
PILOT: How far?
GASSAUER: Six hundred meters in the reverse direction. Then it runs another six hundred and has another.… Supposing the ship is proceeding to port, I set a “left leg” and if it’s proceeding to starboard I set a “right leg.” I believe it always has a rate of advance of six miles.
PILOT: Per hour?
GASSAUER: Yes, six miles per hour, that is its rate of [zigzagging] advance. That’s not the actual [torpedo] speed—that remains the same—but it’s the rate of advance. I can do still better now. Supposing there is a convoy there. I fire a quadruple fan salvo. I set one torpedo at two thousand meters, another at twenty-three hundred, and so on, making them all run to the left. It gives me enormous scope for scoring a hit. This so-called FAT torpedo has proved wonderfully good.
Recorded 4 August 1943 36
BOMBER PILOT, JU. 88 [RE: FAT]: Do the ratings know all about it?
BRINE: They don’t know anything about it at all.
PILOT: Then you know about it and the torpedoman’s mate?
BRINE: Yes, our torpedoman’s mate is an old … Let’s hope he doesn’t say anything. My Commander was a very old hand; he’s already made twelve war patrols; he [Interrogation Officer] won’t be able to shake him.
It’s supposed to travel like this: it can be set in a variety of ways, of course—short zigzags, narrow zigzags, wide zigzags, and in fans. With that torpedo you score a hit ninety-eight or ninety-nine times out of a hundred.
PILOT: Isn’t it a question of judgment?
BRINE: No. I aim at a target. Of course, if I hit my target [straightaway], so much the better, the ship i
s then done for in any case. And if it’s a bad shot and the torpedo goes past.… [I’ve] over-or underestimated the range. Usually you underestimate the range, or you underestimate the ship’s speed. You’re hardly likely to make a mistake in working out the angle of your target, unless the ship passes out of range or zigzags just when you fire. Nearly all the big merchant ships, the fast independent ships, have search gear and, at the moment of firing, they detect it and watch out; they then turn aside and the torpedo goes past. Supposing it goes past here, the torpedo has been set with this preliminary run and it zigzags with the target, so there are always various possibilities of it finally scoring a hit. This torpedo is the right weapon for attacking convoys.…
Recorded 31 March 194337
KLOTZSCH: … Those fellows [the English] have excellent instruments. Have you seen the semicircular thing up aloft, which moves round in a circle? It’s a sort of semicircle, about as big as this, which moves round at this speed the whole time; that’s the thing which our G.S.R. [German Search Receiver] receives.
MARCH: Yes, that’s the radar, that’s the same thing; they have the radar, with which they emit a beam.…
KLOTZSCH: And then they had a sort of network round the mast, and the thing at the masthead, a sort of network right up aloft. That’s for use on the surface. That corresponds to our G.S.R.
MARCH: Yes, they receive with it.
KLOTZSCH: That is their receiver; their transmitter is below. They also have excellent hydrophones, and this asdic as well.
MARCH: That asdic must be a marvelous thing.
KLOTZSCH: It is! And recently, of course, there’re … beams penetrating below the surface from above—as in the case of aircraft.… Aircraft can now establish the presence of U-boats when submerged. That’s the so-called.…
MARCH: … Ultraviolet rays.
KLOTZSCH: Yes, it has something—no, not ultraviolet; ultraviolet are rays which can only be rendered invisible, that is, that have such a short wavelength that they are invisible—inaudible. No, that’s something else—well, they are frequencies to which the medium of water offers no resistance.
MARCH: But that must be something very special.
KLOTZSCH: They are shorter than—I believe you speak of wavelength zero—from nought to ten centimeters, I believe; thus, they’re extremely short waves which strike the water with such an impact that the water offers no resistance.
MARCH: They must have absolutely terrific energy.
KLOTZSCH: They have.
Recorded 26 May 194338
BRÖHL: It is a normal receiver, but somewhat specialized for certain wavelengths.
FIGHTER PILOT, F.W. 190: Which wavelengths are they?
BRÖHL: Destroyer wavelengths; they usually work on the one hundred eighty meter band and aircraft on the one hundred forty band. I can’t remember the number of kilocycles at the moment.
PILOT: Then that’s a receiver and you have someone sitting at it all the time?
BROHL: It’s a normal receiver and a man sits at it with headphones.
PILOT: And at what distance can he [detect] an aircraft’s radar?
BRÖHL: The range is fairly large.
PILOT: Ten miles or so?
BRÖHL: Even at twenty miles.
PILOT: And a destroyer?
BRÖHL: A destroyer as far, too. It depends also on the atmospheric conditions at any given time.
PILOT: You don’t have a special aerial or anything, do you?
BRÖHL: Yes, you have a special aerial, which is put up on the bridge; it’s a simple cross with horizontal and vertical bars. The destroyer radar wavelengths are vertical and the aircraft radar wavelengths are horizontal; or rather the other way around, the destroyer radar wavelengths are horizontal and the aircraft radar wavelengths are vertical.…
PILOT: And is that simply a cross aerial?
BBRÖHL: Yes, it’s a cross aerial.…
PILOT: It can’t pick up destroyer and aircraft at the same time, can it, because you are listening in to two different wavelengths?
BRÖHL: You can switch over quickly.
PILOT: Oh, you tune in to a different one?
BRÖHL: Yes.
PILOT: I suppose it is spot-tuned, isn’t it?
BRÖHL: Yes.
PLLOT: Must there always be a man sitting at it?
BRÖHL: Yes, there’s always one there in the areas which are in danger of air attack, especially in the Bay of Biscay and to about twenty to twenty-five degrees West.
PLLOT: As far as twenty to twenty-five degrees West. Does the [Allied air] patrol extend as far as that?
BRÖHL: Yes, as far as that. We were in square B[runo] E[mil], I believe that’s three hundred fifty sea miles west of Cape Finisterre. That’s the northwest corner of Spain. We were rather farther south, and on the same day, another boat, which was to the north of us, about in the latitude of the Bay of Biscay, … that is, twenty to twenty-five degrees westward, was bombed by aircraft, suffered serious damage, and had to put back into port. We have to use the search receiver as far out as that. One can say, about two hundred miles west of Portugal, along the whole coast as far as the latitude of Gibraltar, the whole area is in danger of attack from the air.
PILOT: Do you hear it at the same moment as the aircraft begins searching?
BRÖHL: Yes. At first you heard a continuous sound all the time, starting rather faint and becoming louder, but, later on, the boats evolved a better method. When the aircraft is searching you hear the short continuous sound. Then you switch off. If the sound has become louder, you can tell that the fellows are making their approach, they have found you. If it doesn’t recur, you can assume with a reasonable amount of certainty, that it was just an accident. They [G.S.R. operators] always have to search again, as a check, to convince themselves.
PILOT: What would happen if he [Interrogation Officer] found out, for example, that you had something like that [Metox]?
BRÖHL: They know about it. They have noticed that themselves from their lack of success. First, we lost a considerable number of boats … in the Bay of Biscay, boats which were putting out to sea and returning to port. Suddenly their [English] successes stopped. Then they knew that we had some countermeasure.
PILOT: Suppose they changed their wavelengths the whole time, suppose each aircraft searched on a different wavelength?
BROHL: It wouldn’t matter if they did. We can cover the whole scale with our apparatus in any case.
PILOT: Suppose they worked outside the scale?
BRÖHL: In any case, the [G.S.R.] operator always goes over all the wavelengths as a check.
Recorded 21 March 1943 39
MARCH: Have you been on a G.S.R. course?
RADIOMAN FROM THE SILVAPLANA: Yes, in Le Touquet. I was there as an instructor for six months.
MARCH: Then you are a G.S.R. specialist. The one week we were there we were bored to death.
RADIOMAN: Who was your instructor then?
MARCH: The instructor was good. What was his name—a man with spectacles—Rass, I believe?
RADIOMAN: Yes, Heinz Rass. So he’s doing that now?
MARCH: What sort of a course did you have? A short one, too?
RADIOMAN: No, I did the whole thing—
MARCH: They are now training telegraphists simply for the G.S.R. and nothing else, aren’t they?
RADIOMAN: Hmm. G.S.R. and radar.
MARCH: That’s awful you know, it’s so boring. We always have two men on board, one in the W/T compartment and one aloft, who keep two-hour watches. You get absolutely fed up with sitting and turning continuously all the time. On our first patrol, we still had no G.S.R. It was much better then, there was always one Maat and one [radio operator] and during the day … you were always four [on and] four off, but now, since the arrival of that damned G.S.R., the Commander wanted to have … mostly at night—and there were, in all, always three men on watch. Or, even if we had a lot to do, and one fellow got stuck with cipher, three of us had to sit there
on account of the damned thing.
Recorded 25 April 194340
In the following section of extracts the POWs speak of the home front as they saw it last, of the war in general, of high-ranking government officials, and of their U-boat bases. Much more could be selected from conversations about the bases with their U-boat bunkers, or shelters, since that was a popular topic, but the descriptions tend to be repetitive and the few reproduced here can stand for the rest.
VOELKER: The last time I was in Germany and my wife and I came out of the cinema, we heard the strangest languages—French, Dutch, Danish, Polish, et cetera, everything but German. The Germans are shedding their blood at the front and these damned foreigners are sitting in our cinemas. Believe me, I’m fed up with National Socialism. If we win the war, we’ll rebuild Germany and we won’t pay a penny. [We’ll see to it that] they [the enemy] are ruined first. They must be bled white.
NAVIGATOR FROM THE REGENSBURG: if things go wrong, Adolf
[Hitler] will go to Switzerland.
VOELKER: No, he’ll do himself in. [Reichsmarschall] Hermann [Goring] will go to his daughter, who is married and living in Sweden. [Heinrich] Himmler will put on a fig leaf and go to Africa. If things go wrong, the Fiihrer will agree to a negotiated peace. NAVIGATOR: No, England and America will never agree to a negotiated peace.
VOELKER: If peace is made now, we’ll have to go through another war; but I still hope that the Japanese will finish off America.
Recorded 9 May 1943 41
NOWROTH: You’ve no idea how many prisoners of war make a getaway in Germany—every day!
SCHAUFFEL: Really!
Black May Page 37
