War Diaries for Bismarck and Prinz Eugen

Discussions about the history of the ship, technical details, etc.

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Vic Dale
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War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

There seems to be some confusion regarding stated times in the War Diaries (KTBs) for both Bismarck and Prinz Eugen. I believe this stems from the fact that Bismarck's KTB is a reconstruction and Prinz Eugen's (PG) is not the original document. The original document is held by the Bundesarchiv/Militararchiv in Frieberg. The KTB translation which was made for this website is taken from two separate copies. One copy is kept in Admiralty Records and the other copy is held by the US National Archives and Records Administration. This can be checked against what is written on the first page of PG's KTB.

It is necessary question why these copies were made and for what purpose.

At 1300 on the 23rd of May 1941, the Fleet Commander Admiral Lutjens ordered the squadron to put the clocks back one hour. The warning that this was to happen can be seen in the diary entry for 1215 on the 22nd of May under the heading; Order from Fleet for 22 to 23 May 41. Order number four details setting the clocks back at 1300 on the 23rd.

On the 23rd at 1300, clocks were in fact set back and all records in both ships should show this.

Bismarck's KTB was reconstructed at Group West, since the original went down with the ship, so the reconstructed document will have been prepared using using Group West time set at Central European Time (CET).

In order that the actions of the squadron could be assessed and possibly also for training purposes, copies of the reconstructed KTB will have been distributed to various SKL Libraries for reference. Copies of PG's KTB will likewise have been distributed to the same libraries, but only after times had been synchronised between the two documents. That this is synchronisation has been carried out, is evident in the small number of errors, which show the disparity between Group West times and times used in the squadron.

Synchronisation also brings the times in British and German squadron into line, although periodically there is a small slip which incorporates the time difference between the British and German ships. Notably the engagement between Bismarck and Norfolk on the evening of the 23rd. The German KTBs say 1930 and the British logs say 2030. On the evening of the 24th, the British have the TB strike from Victorious starting at 0007 and the German record has it starting one hour earlier.

The Engagement with Hood and PoW is sychronised between British and German records, yet all of the survivors accounts say the battle began before 0500.

When contact with Bismarck was lost on the morning of the 25th, the last sighting of Bismarck by Suffolk was 0306. Had this been recorded in Bismarck it would have shown as 0206.

I don't suppose everyone is going to agree which this immediately, but anyone wishing to investigate should look at the KTBs and see for themselves that errors where significant events have been wrongly recorded, have been recorded a whole hour out and not minutes.

There would be no purpose in keeping a copy of PG's KTB at the Admiralty, unless it had been adjusted to British time (DBST). Then it would have some value for Official Historians, such as Donald Macintyre, and various writers and journalists researching the War At Sea 39-45, who wished access material held by the Office Of Naval information at the Admiralty.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by Herr Nilsson »

viewtopic.php?f=1&t=5926&p=55430#p55421

Please tell me, when Group West was informed what time was used on the ships.
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Marc

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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

I have wondered about this myself, but possibly it is the reason why the Uhrzeitgruppe was included in the signals sent and received after 1300 on the 23rd, when it does not seem to figure in earlier communications, particularly with Group North. This could be to do with events at the time, or an adjustment made to Bismarck's reconstructed KTB or copies of PG's original.

In British ships, the local time mark was given as; A, B, C, etc or Z and there may be a similar mark on German signals somewhere.

Signals are received at the transmitter/receiver station immediately they are sent, so the time of reception should automatically be included in the teleprinter printout. In the event that a signal does not get a response from the addressee, any receiver who did pick it up would relay and afix their own time marks, so that time of reception and time of relay are both shown. This may explain why there are three different times shown on the signal below; 0600, the time of the event, 1656 Uhr and an uhrzeitgruppe of 1524.
0600.jpg
0600.jpg (82.17 KiB) Viewed 4002 times
Encrypting teleprinters take typed verbatim script, encrypt it and send it. Reception is simultaneous with transmission and the receiving set automatically decrypts and prints out the verbatim message. These automated encrypt/decrypt teleprinters, Lorenz being one of them, using "Fish codes" (Dolphin, Shark, Porpoise etc) were never sent to sea, so decryption of signals from Lutjens will have been done on an Enigma machine at Group West . This btw is a clear indicator that the German High Command did not have blind faith in Enigma as is so often thought. It was secure for tactical purposes but was not secure for strategic considerations. Strategic signals would not be sent that way.

Ship-to-Shore transmission, Bismarck/Group West, will have relied upon simple, send/receive teleprinters without the encrypt/decrypt hardware.

When I was at sea, the time change was given and all watches and clocks in the ship were reset. All logs will have noted the time of change too. In the RN clocks went forward at midnight and went back at midday. We would lose an hour's sleep or gain an additional hour of work. If you can't take a joke, don't join! Setting the clocks back in Bismarck at 1300, shows that Lutjens also had a sense of humour.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by wadinga »

This thread serves no purpose and should be ignored.

:kaput:
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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

Mr Waddingham serves no purpose and should be ignored.

Further in answer to Herr Nilsson's question about how Lutjens communicated local time to group west, I have been looking at signals sent by Suffolk to the Admiralty in London. The signal's time was given and was followed by a letter suffix - 0600 (B) - as an example. This denotes 0600 but using Bravo Time.

It is clear from the KTBs of both Bismarck and PG that such notation is not shown. Since PG's KTB is a copy constructed from two copies, one used at the Admiralty in London and the other by the NARA in the USA, the time mark would not be shown as the documents have already been synchronised with time in the British ships. There can be no doubting that the KTB for PG is not the original and as Bismarck's KTB is a construct, we are not being shown the actual times recorded, just the event times aligned to times in the British ships.

Bismarck and PG set their clocks back one hour at 1300 on the 23rd establishing the time in the German squadron at one hour behind that used in the British ships.
From the Baron's book;
CET DBST GST.jpg
CET DBST GST.jpg (87.16 KiB) Viewed 3962 times
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Re: War Diaries for Bismarck and Prinz Eugen

Post by Herr Nilsson »

Vic Dale wrote: Further in answer to Herr Nilsson's question about how Lutjens communicated local time to group west, I have been looking at signals sent by Suffolk to the Admiralty in London. The signal's time was given and was followed by a letter suffix - 0600 (B) - as an example. This denotes 0600 but using Bravo Time.
So what?
Vic Dale wrote:It is clear from the KTBs of both Bismarck and PG that such notation is not shown. Since PG's KTB is a copy constructed from two copies, one used at the Admiralty in London and the other by the NARA in the USA, the time mark would not be shown as the documents have already been synchronised with time in the British ships. There can be no doubting that the KTB for PG is not the original and as Bismarck's KTB is a construct, we are not being shown the actual times recorded, just the event times aligned to times in the British ships.
That means Brinkmann held an autograph session for the Admiralty and NARA after the war.
Vic Dale wrote:Bismarck and PG set their clocks back one hour at 1300 on the 23rd establishing the time in the German squadron at one hour behind that used in the British ships.
From the Baron's book;
CET DBST GST.jpg
That's right, but what "Bordzeit" had Group West?
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Marc

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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

I don't know what Herr Nilsson is driving at here, but it might help if he presented any questions directed at myself in English, as I am not a German speaker. As this is an English Language site it might be good manners to present himself in English in future, so that other non German speakers can understand, otherwise his points may continue to be lost.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by Herr Nilsson »

Bordzeit means time on board. So what is an "Uhrzeitgruppe" you're talking about?
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Marc

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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

I would assume that Group West was using German Summertime, the same as Group North.

The matter at issue is the disparity between Double British Summer Time (DBST) which was used in the British Ships and Central European Time (CET) which was used in Lutjens' squadron. I would expect Groups; North, East, South and West to synchronise with Berlin and for themselves to act as interfacing with vessels operating in far flung locations.

I am only able to grasp what an Uhrzeitgruppe is, because it has been dealt with so often and figures in the KTB. Do I have the spelling right? You may use other German terms, but don't expect me to understand them unless some explanation has first been given. I believe I am now correct in assuming that a "zeit" is a time. This btw has only just dawned on me. German is not my language and probably never will be.

You may have noticed that I frequently explain that a KTB is a War Diary and give the full designation to any shipboard measure, or item of equipment, location etc. This is simple courtesy to any inexperienced people who might be showing an interest in the discussion. If you want abbreviations, naval slang and military jargon, I know enough to make your head spin. I stay off that stuff as much as possible, because to use it might seem pretentious and would not be helpful to younger less experienced people.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by Herr Nilsson »

Vic Dale wrote:I would assume that Group West was using German Summertime, the same as Group North.

The matter at issue is the disparity between Double British Summer Time (DBST) which was used in the British Ships and Central European Time (CET) which was used in Lutjens' squadron. I would expect Groups; North, East, South and West to synchronise with Berlin and for themselves to act as interfacing with vessels operating in far flung locations.

I am only able to grasp what an Uhrzeitgruppe is, because it has been dealt with so often and figures in the KTB. Do I have the spelling right? You may use other German terms, but don't expect me to understand them unless some explanation has first been given. I believe I am now correct in assuming that a "zeit" is a time. This btw has only just dawned on me. German is not my language and probably never will be.

You may have noticed that I frequently explain that a KTB is a War Diary and give the full designation to any shipboard measure, or item of equipment, location etc. This is simple courtesy to any inexperienced people who might be showing an interest in the discussion. If you want abbreviations, naval slang and military jargon, I know enough to make your head spin. I stay off that stuff as much as possible, because to use it might seem pretentious and would not be helpful to younger less experienced people.
Vic, there's often no exact translation possible or - much more often - I simply don't know the right technical term. Anyway, "Uhrzeitgruppe" is a term in regard of the encrypted messages. An encrypted message constists of several "Gruppen" which is plural of "Gruppe". The literally translation for "Gruppe" is "group". A better translation would be "segment". "Uhrzeitgruppe" is a compound of "Uhrzeit" and "Gruppe". "Uhrzeit" (actually a compound of "Uhr" = "clock" and "Zeit" = "time") means simply "time". So an "Uhrzeitgruppe" is the time segment of an encrypted message. The "Uhrzeitgruppe" was generated during the encryption. The encryption keys were changed every day at 00:00 o'clock. Both parties of a communication have to use the same key at the same time to understand each other.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

Yes I got the time segment bit, but the time segment applies to the transmission. Each hour at the transmitter receivers were divided into transmission and receiving segments, you can read more about it here;

http://www.pust-norden.de/dan_ww2_gb.htm

In brief;

The time segments were intended for receiving transmissions from ships. It was all a very complex procedure which included DF beacons for Radio Positioning and for communicating reception of signals and signal strengths.

"In the event of Norddeich and Utlandshörn falling by enemy action, there was a receiving station in Muiderberg, near Amsterdam, and a transmitting station in Kootwijk (Holland) supported by Norddeich Radio throughout the war.

The encoding keys changed typically once per hour, or at a minimum daily. Depending on the time of day, season, and propagation conditions, the transmission took place on different frequencies in conformance with a defined listening and transmission plan. The hourly operating sequence is shown in the diagram. At the designated times the blind transmission from Norddeich Radio was stopped, and ship messages were received on their frequencies. The ship messages were coded and radiated blindly as a very short signal. Acknowledgment was not direct, but was in the following blind transmission from Norddeich Radio. The contents of the blind transmission were primarily military, but also contained messages for crew members from people ashore. If nothing was available to be sent, the "empty time" in the blind transmission was occupied with "Filling radio," i.e. fictious groups of letters, to confuse the enemy."

We can see this time segment arrangement being used in Lutjen's long message, which was sent in four parts and they are the time segments being used on that day and at that hour. If the time segment for a particular transmission was not used properly, it would not be received and would not be acknowledged. There would be no need to append the time segment to the actual signal as it would be recorded at time of reception. which is simultaneous with transmission.

Incidentally the "bordzeit" you mentioned for Group West had me confused,making me doubt my grasp, because my understanding of Bordzeit was, "Time On Board" which considering Group West is a shore establishment sounds like a misnomer.

back to the long message, I did wonder if Lutjens had had that signal sent long hand - on a morse key with a slow operator, in order to generate a DF fix in the British ships so they would follow him and leave PG well alone. I don't now think that is correct, because he could have filled with fictitious letters groups and kept the British guessing. The signal needed to be sent, possibly so that the SKL would have something to give to the press. Given that so much detail was included, I would consider failure to patch the holes in the bow and exceptional loss of fuel to be included as these considerations far outweigh the value of some of the verbiage contained in that message.

The signal speaks of the ship settling by 1 degree at the bow and that is not a serious matter and would not affect the fighting efficiency of the ship. The list to port was by comparison a much more serious matter, but as that does not get a mention the problem has to have been solved at least by the time of that transmission. A four segment transmission was sent at around 2300 the previous evening and it is thought that this was the same message which became corrupted during transmission. So very possibly the problem had been solved by that time at least.

Given that the ship was slowed during the afternoon of the 24th so that damage control measures could be put into effect I would expect both the list to port and the trim at the bow to have been dealt with, the latter using the collision mat. When the mat became torn during heavy maneuvering in the night, more permanent repairs were required and that must have been sorted out during the afternoon of the 25th. Had this hole in the bow not been properly patched, that fact would have been made known to Group West at the first opportunity, ie after relocation on the 26th. No further mention is made of holes in the bow or effective loss of oil, so given what the survivors had to say combined with nothing from Lutjens to the contrary, Bismarck must have become fully operational once more.

I tend to think that the holes in the bow and the one at the ship's side were only talking points among the crew, once measures to correct them had been put into effect. Had the ship been able to continue the operation after the 27th, the damage would have been an incident for comment only during a very successful operation. After the ship sank with such appalling loss of life, I think these incidents loomed larger in some minds than was really necessary. Even when all hell had broken loose and it was realised that the ship would probably be lost, Lutjens did not think to mention any outstanding defects which had contributed to her loss. I think that speaks for itself. The survivors were a very junior lot and would have a tendency to exaggerate some things and skip over others.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by tommy303 »

The encoding keys changed typically once per hour, or at a minimum daily.
I believe, although I could be mistaken, that German Navy protocols was for each message to have its own unique encoding key except where a message broken down into parts because of length. The daily setting key was only a starting point to encrypt the actual message encoding key. Proceedures in the Luftwaffe and Army were somewhat more lax and frequently the same encoding key was used for multiple messages which greatly helped allied cryptanalysis.

Naval time segments or Uhrzeitgruppen, were, as our good friend Marc says, worked into the message preamble so the receiving party would know what daily setting to use to set up his machine. I believe the Uhrzeitgruppen were based on GMT, at least in the Navy, which could be gotten from the ship's navigational chronometer or select clocks which were always set to GMT instead of the local time zone.

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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

If we look at the signal from Lutjens informing Group West; that the ship had made AK55 at 0700 and that he was still under surveillance, we can see that the tactical time, or time of the event being reported, is included in the message, so there is no need to bog the system down working the time into the preamble of the message and duplicating the work.

The Time Segment or Uhrzeitgruppe is important for getting the chronology right when detailing when messages were sent. As each signal was transmitted the time of transmission would be logged in the main Signals Office in the ship and also ashore as it was received. Periodically the Signals Officer would be presented with a list of signals sent, signals received and signals acknowledged. Each item would have it's own time mark, so that a signal saying "Yes to yours of 1945." Could have the relevant signal attached so the originating officer could see what it meant. Each signal was produced in triplicate so that the signals office could keep a copy on file, the originating officer had his own copy and the signals office had it's working record by which a copy of each signal could be marked and timed as acknowledged. When a signal was sent, a receipt would go to the originating officer with the time marked on it, so he would know when it went out.

If for any reason there was a delay in sending - poor ionospheric conditions, transmitter down etc, the originating officer would be informed and when finally it did go out he would be informed of the time.

There should be a part of a signal which details which time the ship was working to. In the British system the time was given a suffix for example; 0727 (C) "0700 AK55. 1bs 2HCs maintain surveillance. Fleet Chief"

I have just had a look at Scharnhorst's last signal and that has :" Time ended 1832 Z." I am not sure if this was part of the signal or something added by British crptanalysts.
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Re: War Diaries for Bismarck and Prinz Eugen

Post by tommy303 »

Once again, I could be mistaken, but the Uhrzeitgruppen were important references normally worked into the preamble and in plain German, so that the receiver would know at what time GMT the message was encoded so that he could set his machine's rotors for the proper setting and thus retrieve the actual encryption key allowing him to decode the body of the message (the daily rotor setting was not supposed to be used for encoding a message). This might be particularly crucial if the message was encoded at say 2345 GMT but was not actually transmitted until a half hour later. The Uhrzeitgruppe would let the operator on the other end know that he needed to use the day setting for the previous day instead of the setting that had just come into play for the current day.

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Re: War Diaries for Bismarck and Prinz Eugen

Post by Vic Dale »

As I understand it, the encryption key was set each day, according to a standard book distributed among ships and bases making it possible for all units to communicate with each other. The key changed at midnight so there would be no problems until late at night when there might be some confusion as to which key to use. There was an example of exactly that happening with a signal sent by Bismarck at 2302 on the 24th, which could not be read. It was repeated and 3 other signals were sent, none of which could be read. Possibly these were repeats, though that is not shown in the KTB. At 0302 on the 25th Bismarck signaled Group West using the 2302 UZ of the 24th as reference, saying the Encryption Key used was EGN.

It is possible that the Enigma machine operator at Group West, used the time of reception on Group West time for setting the encryption key on his machine, instead of looking at the time set (UZ) on the signal. 2302 in Bismarck would be 0002 at Group West

The encryption key was set by the day at the central time-set - possibly GMT or German Summertime and it would be the time at which the signal was sent, which would set the key for before or past midnight. When encrypting the signal, it would be known in the ship which side of midnight it would go out and the appropriate key would be used. Since the deviation between local time and station time, between a ship and it's base, were in complete hours and with no minutes to complicate things, errors would be kept to a minimum.

I would expect transmitters to stay off the air for a period of about 15 minutes either side of midnight to ensure that the next day's Encryption Key was properly set and checked, together with the plug settings and wheel selections. I am not sure how long it would take the average operator to set an enigma machine up for the day and run a test to see that it encrypted and decrypted properly, but a set time might be needed to see everyone properly up and running.
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