As I've mentioned before, I've been trying to decrypt some Enigma-enciphered U-boat radio messages which were intercepted in November 1942:

[www.xs4all.nl]

This would require a "crib" - some known (or guessed) plaintext - to use as input for a computer simulation of the Turing Bombe. So far, none of my guesses have panned out, so I've been looking in the KTBs of some of the U-boats that were in the general area where the messages were intercepted, hoping to find the plaintext of at least one of the intercepts and use that as a crib to recover the Enigma settings for that day; but unfortunately, I can't afford to order the microfilm reels covering all of the possible boats.

Though I haven't found what I'm looking for in the reels that I do have, there is one message (or rather, part of one) recorded in U-183's KTB on November 19th that looks tantalizingly close:

"1036 Eingang F.T.: 0924 / 19 / 221
2. Schäfer, Rasch, Struckmeier melden, ob Boote nach Ergänzung weiter maschinell und personell verwendungsbereit für Einsatz gegen Geleitzüge. Wenn ja, Schnoor ansteuern und dazu voraussichtliches Eintreffen melden. Für Schwantke gilt gleiches nach Beendigung seiner Geleitverfolgung."

Unfortunately, only the part of the message that applies to U-183 (Schäfer), i.e. paragraph 2, was recorded in this KTB. The same goes for Struckmeier's (U-608); although that KTB is continued on a separate reel which I don't have, and there's a chance that this might include as an appendix some excerpts from the radio log, and that the full text of the message might be there. Schnoor's (U-460) KTB doesn't show this message at all, and I don't have Rasch's (U-106) or Schwantke's (U-43).

The whole message probably consisted of several paragraphs, and would have been divided into two or more parts before being enciphered, and the parts transmitted separately, each with its own time/date group and serial number (e.g. "0924 / 19 / 221") which would be sent in the clear at the beginning of the transmission. After all the parts had been received and deciphered, the whole message would then be designated only by the time/date/serial number of the first part.

One of the intercepts I'm trying to decrypt is marked with its time of reception: "T.O.R. 1152/19/221". If the "221" here refers to the serial number from the transmitted message heading, then this intercept could be a re-transmission of the first part of the message above. If so, then the missing first paragraph, if I can find it, might be the crib I've been looking for. Since the serial numbers from 201 to 300 were assigned to the "Amerika I" circuit, the first paragraph would almost certainly concern other boats operating, like those mentioned in the second, in the western half of the North Atlantic at that time (November 19, 1942). I have microfilm reels with the KTBs of some of them, but none of these has what I'm looking for.

All of this is to explain my request to anyone who has a KTB of any of the following U-boats: U-43 (on T-1022 reels 2929 & 2930), U-84 (on reel 2931), U-106 (on reel 3035), U-224 (on reel 2937), U-264 (continuation, on reel 2887), U-383 (on reel 2889), U-454 (on reel 2838), U-518 (on reel 3068), U-608 (continuation, on reel 3374), U-611 (on reel 4185), U-663 (on reel 3397), or U-704 (on reel 3376). Next time you happen to look at it, could you please check the entries for November 19, 1942, (and the "Auszüge aus der Funkkladde," if these are included) and let me know whether it shows the rest of the above radio message? I'd really appreciate any help I can get.

Many thanks, and my apologies for the long post,

Dan Girard