Authentic BDU/U-Boat transmissions Intercepted by the Allies

[Hartmann]

Amazing stuff.

How they can win ?? it show that it was almost impossible.

later with more destroyers and planes , allied forces can track and pin down the submarines making convoy operations and attacks impossible.

[Puster Bill]

A thought just occured to me: For sound file purposes, a better thing would probably be to make a "short signal", because they would be shorter in length then a regular message.

Formatting for a short signal can be found here:http://users.telenet.be/d.rijmenants/en/kurzsignale.htm

It looks like this:

BB
RDF QRLE ATMG SIKR ODX RDF

Where "BB" is actually a "Beta". I'm not sure of the Morse equivalent for Beta: I learned International Morse, and the extra four characters needed for Slavic languages, but I'm not familiar with the "Beta" character.

If anyone knows what it is, let me know and I'll create a short signal we can use.

[Puster Bill]

OK, after looking around a bit, I found that originally the short signals sent an Ä twice, which is .-.- (didahdidah). The British called these "E-bars".

I found out that as I suspected earlier, the "Beta" was a common Morse prosign, BT, which is -...- (Dadidididah).

Weather signals used a WW in front of their messages.

When I get some time, I'll gin up a Kurzsignal message and post it to Youtube.

[Puster Bill]

If you take a look at this page:
http://wwiiarchives.net/servlet/documents/grm/110/0

You will see several WWII German code books, including a Kenngruppenheft from 1944, a U.bootsabivehrsignalheft (U-boat signal book) from 1941, and a Wetterkurzschuessel from 1942.

The U.bootsabivehrsignalheft appears to have several pages of "short signal" type messages. My ignorance of German prevents me from getting more than just a glimmer of the contents, but I'd guess that this isn't a true kurzsignalheft. It actually appears to be codes used when transmitting using the underwater signalling gear (something I deduced from some crappy Babelfish translations, and the preponderance of the root "horch"), something that would have been done in training but not in actual combat.

[Puster Bill]

OK, I've put that short signal from up above on Youtube:



It's hand-keyed Morse using a straight key, just like a radio operator on a u-boat would have done.

I timed it, and I'm doing about 19 or 20 words per minute. The whole thing takes about 15.7 seconds to transmit, on a good day I'm sure I could get it below 15 seconds.

As you can see, that would give the HF/DF operators both on ship and at shore stations precious little time to get a bearing on the signal, which is the whole idea of using a short signal. I haven't actually made any CW contacts for a few months, so I'm a little rusty (yeah, ignore that sloppy "X" at the end of "ODX"). If I were doing it all the time, I'm sure I could go faster.

Anyway, if any modder wants to use the audio of that to replace the incoming message sound, be my guest. If you need a purely audio file to convert to OGG, I can make up a decent WMA.

[papa_smurf]

Great find, can't wait for these to appear in a future mod

[defcom]

Hi Folks,

I saw your reference to the raw intercepts of the M4 prject. If interested, I have a special page on the first of those messages (stripped of the FCLC and QRKN indicators), which describes in detail how to decipher the message (you can use my Enigma simulator). I also added some information from the archives about the U-boat U-264 that sent the message back in 1942, and how the U-boat was finally sunk.

http://users.telenet.be/d.rijmenants/en/m4project.htm

enjoy the reading (and deciphering if you fancy playing with the sim)

Kind regards,

Dirk Rijmenants


Cipher Machines & Cryptology
http://users.telenet.be/d.rijmenants
http://rijmenants.blogspot.com

[Puster Bill]

Howdy Dirk!

I have to say, I've been playing with your cipher machine simulators for a while now. Absolutely love 'em, especially the Enigma. Top notch!

Hope you don't mind that I used your examples for my CW videos.

My real interest was the external formatting, having been a SIGINT Morse interceptor a *LONG* time ago. That's the kind of thing that's really only of interest to real nerds like me.

[nikimcbee]

That's my B-day! What a present: a convoy engagment!

[Puster Bill]

By the way Dirk, I see that you have at least partial images from a Kurzsignalheft on your website.

Do you know if there is a place on the web that has an entire short signal codebook? Translated would be great, but probably too much to hope for. I'd settle for images of a real one and my German/English dictionary.

[Vorperblad]

A little piece of U-boat War history --->Right There!! Good one Laufen

[defcom]

Hi Puster Bill,

Here's a nice place to look:

http://wwiiarchives.net/servlet/documents/grm/110/0

(copyrighted and all rights reserved!)

[Puster Bill]

Originally Posted by defcom

Hi Puster Bill,

Here's a nice place to look:

http://wwiiarchives.net/servlet/documents/grm/110/0

(copyrighted and all rights reserved!)

Yeah, I looked there.

The one is a kenngruppenheft, which is for setting the enigma but isn't actually a 'short signal codebook', and the other has short signal-like code groups in it (the U.Bootsabivehrsignalheft), but those appear to be for underwater signaling use using the underwater telegraphy set, something that was not generally done on an active war patrol because the 4.12 KHz audio frequency used would have been very audible to any passive sonar set in the area.