Bismarck radar detector

[wadinga]

Hello Hans,

Clearly you are irrevocably wedded (welded?) to the post-war supposition by some commentators that Bismarck had a dedicated radar detector, and the lack of mention of one in Feindliche Ortung, even when talking of something similar for Lutzow does not faze you. Equally, you are prepared to invoke anomalous propagation or a considerably-revised Bismarck track just to allow a possible detection range at 07:00 to explain why Lutjens sent his inaccurate, and incomprehensibly wrong, tactical assessment.

Again please excuse the clunky translation from Feindliche Ortung

It must therefore be assumed that the battleship "Bismarck" has located the enemy flawlessly as 3 targets by careful Em II measurements even after 0300 and even around 0700 despite the lack of optical vision. It was not until 25.5. in the morning that "Bismarck" finally lost touch, stopped locizing or no longer reported any location results. This fact that battleship "Bismarck" still had Dete tracking when the British contact had been lost indicates at least the vulnerability to interference on the British ships of existing equipment. It also ensures that careful use of one's own Em II devices remains hidden from the opponent.

Fricke does not mention any speculative proto-Metox detecting enemy transmissions, but instead Bismarck's own radar tracking them. Maybe there is a subtlety in the German original, which I have missed.


But we can agree to differ.

However, we also have the following in the Chapter 7 notes in Ludovic Kennedy's "Pursuit" pub March 1974:

Captain Giessler, one of the German Navy's last war radar experts, has informed the author [Kennedy] that Bismarck was not equipped with an FuMB, or radar search receiver, (an instrument designed to pick up enemy radar transmissions).

This seems to be a definite resolution of his equivocal position as outlined by Dave, earlier.

All the best

wadinga

[hans zurbriggen]

Hello Mr.Wadinga,
I think am not 'welded' to my view more than you to yours.
'Anomalous propagations' are very common and happened frequently on May 23 and 24, when Suffolk 'invoked' refraction effects even on visible wavelengths.
I trust post-war authors who referred that BS had a passive receiver onboard because this is logical explanation to 1) Lütjens repeated undoubted messages, 2) to Gruppe West request to determine enemy frequencies and 3) to 07:00 message.
Imho 'Feindliche Ortung' did not mention BS receiver because of secrecy, need to know, and opportunity: mentioning a (too sensitive?) prototype while deploying a passive detector to all ships may have generated doubts about its effectiveness).
Of course we may agree to differ and you may be right.
Apparently Giessler told Kennedy something different than what he read on wartime documents:

Mr. Saxton: 'Giessler stated that the device was equipped with a special broadband antenna which allowed it to pickup all the necessary wavelengths, although the directional accuracy would have been very poor.'

explaining the genesis of 07:00 message when passive receiver got emissions from 3 CS1 radars from a similar direction.


hans

[Herr Nilsson]

Hans,

where is the FuMB-antenna?

[hans zurbriggen]

Hello Mr. Nilsson,
if antenna is located, no need to discuss here.

hans

[wadinga]

Hello Hans,

We can agree to disagree, and present our evidence, but keep things very gentlemanly and friendly. after all we are all enthusiasts here!

A fuller quote of Dave's post is:

Giessler began his commentary on this specific issue by stating that it is no longer possible to know with certainty if Bismarck had the means to detect enemy radar pulses. He informs that the author of the document assumed that Bismarck did have a prototype device onboard, but that the author's assumption could not be confirmed.

Nonetheless, Giessler continued on that it was possible that Bismarck had such a device because there was such a experimental device developed at the time. Furthermore, Giessler stated that the device was equipped with a special broadband antenna which allowed it to pickup all the necessary wavelengths, although the directional accuracy would have been very poor.

I would suggest that by selectively quoting only that part in italics, you have inadvertently changed the whole tenet of the post. Giessler says in the opening sentence it is not possible to say whether or not Bismarck had a detector. He then goes on to reference a wartime author from an unknown and lost document who assumed Bismarck had a detector. He then mentions a system which could have been on the Bismarck and this includes the characteristics you have referenced. At no time does he confirm such a system was on the Bismarck.

I wanted to find out where and when this material from Giessler originated so as to date it relative to his flat-out denial quoted in Kennedy published 1974.

I'm afraid the "secrecy" argument is really hard to accept. To hide the knowledge of such a system on Bismarck, whilst freely discussing a system in Lutzow makes no sense. To "forget" the existence of a system detecting British radar in Bismarck and ascribe the 07:00 identification to Bismarck's own radar as if unaware of the existence of the former, is incomprehensible considering the security clearance of Fricke and the addressees.

I cannot see why discussion on whether any visible external manifestation of a system in Bismarck, such as an antenna should not be discussed here.

all the best

wadinga

[hans zurbriggen]

Hello Mr. Wadinga,
quoting Mr. Saxton I wanted just to point out that Giessler said another thing to Kennedy, sorry for having cut and paste only a piece, but you respectfully did the same (my underlined):

Mr. Saxton : 'The author of the document assumed that this device was installed on Bismarck. So it was possible, perhaps even probable, but it cannot be proven'

To avoid any further misunderstanding, I would suggest we refer to his full post: https://www.kbismarck.org/forum/viewtop ... 126#p88126 instead of mentioning only our 'preferred' sentences.

I agree we cannot know with certainty, but imho evidences (see 1), 2) and 3) in my previous post) are pointing to BS being equipped with a passive receiver (and crew being trained to determine enemy radar frequencies).
Secrecy may be a minor issue (I don't believe it was during war) but 'need to know' and 'opportunity to divulgate' are still valid points to avoid to speak about what was experimented (without much success) on BS.
Giessler's mysterious author says what Hepke states too (and other authors too, including the Baron).

My point re Mr.Nilsson question is that whether FuMB antenna position was known, then we would have no need to discuss in this thread, because the presence of passive radar on board was self-demonstrated by presence of a FuMB antenna: sorry for not explaining well my point.

hans

[wadinga]

Hello Hans,

Can we agree it is only Dave Saxton who says "possible, perhaps even probable" and not Giessler the wartime German radar expert, whose two opinions are either " it is no longer possible to know with certainty if Bismarck had the means to detect enemy radar pulses. and " Bismarck was not equipped with an FuMB, or radar search receiver,".

Dave clearly says:

I concur with Giessler that it cannot now be determined but I think it as probable.

Giessler as quoted by Dave makes it clear the "mysterious author" only assumed, but did not know.

Dave has extrapolated with his own considered opinion to "probable", well beyond Giessler's equivocal first-quoted observation and therefore it is critical to find out in which order Giessler's two statements were made. Giessler's work: Der Marine-Nachrichten- und -Ortungsdienst - Technische Entwicklung und Kriegserfahrungen pub 1971 is an extensive study, I believe, and might be considered more authoritative than Hepcke, badly-translated webdoc (also he was concerned with aviation) or Ludwig (largely concerned with purely electronic matters).

What I believe Herr Nilsson was observing, is that since there is no photographic evidence there was a recognisable big ship FuMB antenna aboard Bismarck, it points to there being no receiver either.

The whole point of Fricke's Feindliche Ortung is to disseminate in a Top Secret document the lessons from Bismarck's deployment. There could be no excuse for leaving out reference to a detector system in Bismarck, whilst discussing one in Lutzow, With respect, you have not addressed that Fricke's document assumes Bismarck's own EM II system tracked the British shadowers and not a speculative detector system, which is not mentioned at all.

All the best

wadinga

[hans zurbriggen]

Hello Mr. Wadinga,
I tend to agree with Giessler that it is impossible to be sure, but I think it is very probable with Hepke, Ludwig, the mysterious author of the lost document, the Baron, etc.
No small antenna (nor any manually rotated one, like 'Honduras') can be visible, especially in (possibly censored) images. Used antennas could have been simply the radio (HF and UHF) ones, as Mr. Saxton explained us.
From your side, you have not yet exhaustively addressed 1) Lütjens repeated undoubted messages about the presence of enemy radars, 2) Gruppe West request to determine enemy frequencies and 3) 07:00 message, detailing the three ships shadowing Bismarck: all point to presence of receiver and crew trained to use it to find frequencies of enemy radars, as it was the logical conclusion from most authors.

In conclusion, I repeat the invitation to agree to disagree on this topic, because imho no certainty can be achieved in any case, surely not based on Fricke's document, just not mentioning its presence (but not denying it, as well).

hans

[Steve Crandell]

Group West could have been mistaken about Bismarck's capability w.r.t. determining the frequency of British Radars. It wouldn't be the first time higher organizations made mistakes like that. Or, they could make the request in the hope that the capability existed without knowing one way or the other.

[wadinga]

Hello Hans, Steve and anybody else who is interested,

I believe i have addressed items 1, 2 and 3 already.

To reiterate and expand. Hopefully exhaustively.

!) Given his knowledge of Bismarck's own EM II capabilities it would only be logical to assume the enemy was using radar and not some arcane and unknown technology. As we know from Feindliche Ortung SKL was well aware of British land based and even airborne radars, and Lutjens would have been expecting British warships to deploy something similar, sooner or later. It is only with hindsight, hugely distorted by Brinkmann's exaggerated and never-to-be-repeated claims for GHG performance, that one might think any other kind of sensor was involved. Feindliche Ortung wastes an inordinate amount of consideration due to Brinkmann's unfounded speculations.

2)As we have established, it is perfectly possible but not easy to detect lower frequency radars using communication radios. However because their performance in their primary role requires a very narrow tuned frequency, scanning around to detect the very short blips of radar pulses would be very difficult, hence specialised radar detectors which monitored spread frequencies were required. As Herr Nilsson as a native German speaker has observed, SKL's request is not an urgent demand for a report on frequencies detected, but more an expressed hope that if they could be identified, jamming devices could be developed. It remains the case that Bismarck had many hours whilst being shadowed to report such information if it had been available from a speculative proto-Metox or any other method but no such information was passed.

3)"Most authors" dutifully follow what previous authors have speculated, and unlike us, have almost certainly not had access to Feindliche Ortung. Lutjens' UHR 07:27 message remains inexplicable although I am beginning to have some thoughts on a possible "out-there" tactical reason. "Most authors" have speculated a radar monitoring device to avoid suggesting Lutjens and his staff were unbelievably stupid and professionally incompetent by making radio transmissions and telling the British how to find them. The Baron, who was there, only speculates there might have been a radar detector amongst other options. He lists several possible reasons for the UHR 07:27 message, including that Lutjens and his staff had become so used to being tracked they did not bother to check whether they still were! B-Dienst intercepts and decodes should have shown this. That is perilously close to calling them stupid and unprofessional. I do not believe Lutjens and his staff had these failings and I am coming to the view there was method in their apparent madness.

Now, since Fricke and SKL must have known whether there was a radar detector on Bismarck, or not, why do they assume in Feindliche Ortung that it was Bismarck's own active EM II tracking British shadowers and not one way radar impulses which we all agree have much longer range? How would EM II returns identify the ships involved, when they would just be spikes on a trace? Clearly they they knew there was no dedicated radar detector which could explain the inexplicable.

Far from from dismissing Feindliche Ortung which specifically addresses why Bismarck might think she was still being tracked, and does not mention a detector for her, whilst including highly secret details of a system for Lutzow, we should realise we now have better information than the speculative assumptions and assertions of probability made previously.

Once again we should all consider ourselves hugely indebted to Mr Rico for providing first class top secret primary sources for our study, instead of having to rely on guesswork and speculation. Most sources say it was the 1942 capture of a downed Wellington in the Mediterranean which revealed the existence of ASV, but Feindliche Ortung tells it happened in mid 1941.

All the best

wadinga

[hans zurbriggen]

Hello Mr. Wadinga,
you have addressed my points, but imho not in a satisfactory (and simply logical) way:
1) why do you think Lütjens was so more clever than Brinkmann (who had the same EM II and information available) and the whole SKL (including Fricke) ? This is not the logical explanation for Lütjens messages: everyone (even 1 month after facts) was unsure about British naval radar presence. The messages logically point to BS having detected radar emissions.
2) On a radio receiver you can hear just audible noise, you cannot determine frequency used by emitter. The idea that Gruppe West wasted time to express a 'hope' within an operational message is not plausible and again an unneeded exercise of imagination. BS might have actually determined frequencies but you don't transmit in any case such secret info, even coded. You put them in a report.
3) Most authors came to the only logical (and simple) conclusion, supported by 1941 availability of KM passive detectors, confirmed by all sources. The Baron technical description of Bismarck is mostly correct. He does not 'only speculate' about a passive receiver. He states BS had it, describing (correctly) in detail its functioning and limitations (chapter 20): why to imagine he 'invented' the whole story ? Why should Hepke 'speculate' that BS had a passive receiver when he was responsible to study the development of radar equipments ?
I respectfully feel that a 'speculation' exercise is much needed not to recognize that presence of a passive radar is the only logical conclusion (explaining 07:00 message too).

hans

[wadinga]

Hello Hans,

Whilst you are reading Chapter 20 you might notice the Baron lists four potential reasons why the UHR 07:27 transmission was made, breaking radio silence, and giving the D/F stations a chance of locating Bismarck. The first is indeed the use of a radar detector, but reading on, you will notice he dismisses this reason, thus:

I would, however like to exclude the first.

because

It is difficult for me to believe that radar pulses were still being picked up by the Bismarck at 07:00.

This is after consultation with HHvS in 1984 when that gentlemen's recollection of 40 years before had even added a radar detector to Prinz Eugen's 1941 outfit, which no-one considers is the case now, and is not mentioned at all in the PG KTB. Undoubtedly this 1980s discussion is where the Baron got his impression Bismarck also had one and some idea of the capabilities of such a system when they did become available. PG got her radar detecting installation in early 1942, like Scharnhorst and Gneisenau ready for Operation Cerberus. The Baron's explanatory footnote cites "the great distance" at 07:00 as the reason for dismissing this possibility.

That HHvS was misremembering what PG had in 1941 is confirmed in Feindliche Ortung:

The commander of the cruiser "Prinz Eugen" has reported that no British Deteimpulse have been recorded; however, since there were no other observation devices on board, this only confirms that existing British Dete devices do not work near the German Em II wave.

So contrary to what he told the Baron in the 1980s, PG had no radar detector during the mission and SKL considered PG's report showed British radar operated outside the frequencies EM II could detect in listening mode. Even at this point, no mention is made of Bismarck having a superior detecting capability, clearly because it didn't.

Why Brinkmann was so keen to exaggerate the performance and value of GHG is a whole different matter and a search through old threads will throw some light on this. Fricke and SKL were misled into considering an imaginary British passive sonar system because the senior surviving officer of the mission was prepared to invent a listening system on the north Iceland coast as well as units on the British ships and include this fabricated information in his supposedly factual KTB.

Since radar transmits on a very narrow specific frequency with little bleed over into adjacent frequencies it is indeed possible to determine frequency using a radio receiver. However, you have to be able to identify the pulses of radar output through prevailing static and be tuned to precisely the right frequency to find them. Also since the beam is narrow the transmitter has to be directed at the receiver for it to be able to pick up transmissions. Feindliche Ortung includes the wavelengths of British radar stations used in the Channel because given a considerable length of time, conventional radio receivers operating in the VHF waveband could identify them. It makes clear the British were doing the same to the German Seetakt-based radars they had installed on the French coast.

Confusion may have been created in an earlier post where it was suggested that a very close radar may cause wide band interference on nearby receivers eg the TV example when transmissions had moved into the UHF zone. This is because the high power output literally causes the receiver's internal circuitry to resonate creating interference, at very short range. This is very different to tuning a radio receiver to the correct frequency to pick up distant radar.

Only Lutjens and his team were in a position to attempt to pick up British warship radar transmissions in May 1941, using whatever was at their disposal, the receiver element of their FuMO systems if the frequency was within their range, or VHF comms receivers if they could overcome the difficulties mentioned above. There is no "waste of time" involved in requesting Bismarck to try and determine frequencies and since Enigma encoding is considered utterly impregnable, no security risk in transmitting such vital information as soon as it became available. Clearly it didn't- likely because there no radar detector onboard. It could not be more highly secret than Bismarck's destination, St Nazaire, which was transmitted.

Once again, we must remember Hepcke was involved with specifically with air ministry and Luftwaffe radar, the Kriegsmarine was another world. He surely cannot be regarded as reliable as Giessler on naval matters.

Since we have Feindliche Ortung to refer to, we have no need to speculate/ logically deduce the presence of a radar detector as previous commentators have, as an excuse for the incomprehensible breaking of radio silence of the UHR 07:27 and subsequent transmissions. We need to look elsewhere.

All the best

wadinga

[hans zurbriggen]

Hello Mr.Wadinga,
please concede that the Baron never 'got the impression' BS had a passive receiver: he said it had (as a fact). His technical description of BS is mostly correct, so I don't see any reason why we should doubt of his detailed description of this system (see below from chapter 20), whatever is his opinion (this is an 'impression') about 07:00 message genesis.

Baron_FuMG.png (57.81 KiB) Viewed 1222 times

I'm afraid you cannot use a simple radio receiver to establish frequencies of pulses, you hear noise in the audible wl's (affected also by pulse repetion frequency + harmonics, not only by the emitted frequency within pulse) and that's all. The TV noise example is correct. To find the frequency you don't use a radio receiver because you don't need to demodulate the signal (as in a radio or TV receiver), you just adjust receiver to the frequency max power without demodulating it (establishing wl, frequency, strength and approx direction, as per the Baron). This is not a radio receiver, it is a passive radar receiver with a directional antenna. The request to establish British radar frequencies is therefore a key evidence that BS had one on board.

You have mentioned (in your above post) a key sentence of 'Feindliche Ortung' that explicitly says PG had no detector, while no such statement is extended to BS. Why ? Apparently F.O. doc decided not to mention it for a good reason (I feel opportunity was prevailing one)

I have not seen any better document on German radars than Hepke (responsible for radar studies at air centre of researches, listing almost all different radars (naval too) with availability dates e.g. for Metox and Samos). Have you ? Which is your reference for German radars ? Hepke is in agreement with the Baron, with Ludwig, with the mysterious author Giessler speaks about and with all messages from and to Lütjens.

To use the mere 'absence of explicit mention' in F.O. to deny all these evidences is imho largely insufficient + it does not allow to explain what happened.

hans

[wadinga]

Hello Hans,

Does it not seem illogical to contend that the proto-Metox was so secret that Kurt Fricke could not acknowledge its existence in a top secret document, specifically dealing with the motive and consequences for breaking radio silence, and yet the fourth gunnery officer in Bismarck was fully conversant with its existence and capabilities in 1941? As I have observed it is obvious that the Baron got his information from HHvS in the conversation in 1984 by which time that gentleman had also imagined Prinz Eugen had one.

Here we see again the value of primary documents like Feindliche Ortung instead of relying on the often cloudy, and influenced by later discussions and information, remembrances of forty years before. It would be interesting to know whether the Baron included this equipment specification in the first 1980 edition of his book.

As we established earlier, British operatives using the standard Army Type 19 VHF radio receivers determined the operating frequency and locations of German Seetakt installations on the Channel coast in February 1941. (F A Kingsley) It was possible but not at all easy to determine frequency of radar operating in the VHF band on a conventional communications radio. As the wavelengths grew shorter, pushing frequencies into the UHF band, things got even more difficult. Asking Bismarck to try to determine frequencies is not proof of a detector, and no frequencies were actually reported.

Whether Hepcke is "better" than anyone else is difficult to say. We all acknowledge it is badly translated, hard if not impossible to locate in original German, and certainly comprehensive in those areas he had some experience of. However, the flat denial that Bismarck had a radar detector by Giessler, who was a published author on Kriegsmarine radio matters is surely more reliable. Fritz Trenkle is another German radar specialist, does anyone have his book?

F.O.

explicitly says PG had no detector, while no such statement is extended to BS. Why ?

Because it specifically goes on to ascribe the identification of British shadowers to Bismarck's active radar EM II. It does not even the consider the possibility that a detector aboard Bismarck was responsible- I would suggest for a very obvious reason! There wasn't one!

All the best

wadinga

[hans zurbriggen]

Hello Mr. Wadinga,

the Baron did not get info from HHvS in 1984: he wrote about a passive radar receiver in 1980 in his first edition with same wording (limited directional capability excludes radio receiver), except footnote. His info of all aspects of BS equipment (including radars) is correct and this one is confirmed by Hepke, Ludwig and Giessler's mysterious author. Thus it is highly probable, close to be certain imho, but we can agree to disagree, missing new evidence.

Giessler said only that it was not possible anymore to demonstrate with certainty that there was a passive receiver.
I do not have Trenkle's book, but he lists Hepke's study as a source of his work: I would be surprised if he denies a passive radar on BS.

'Feindliche Ortung' never said BS had no passive receiver. F.O. did not mention it due to opportunity reasons (not to say that SKL was deploying a system that led to BS destruction, due to incorrect data interpretation). Why the document explicitly says PG had no detector, avoiding to say the same for BS ? I'm afraid your explanation is not sufficient: if there was no passive receiver on ALL German ships, F.O. would have simply said so, not specifying PG had not.

hans