Saturday, October 06, 2007

The "Kurier" Kurzsignal System

At the end of the Second World War the Kriegsmarine - the German Navy - experimented with a new system of radio transmissions to counter the threat of Allied HF Direction Finding. The "Kurier" system, based on what now is called burst-encoding, reduced the transmission time of a Kurzsignal - a short signal message - to only 340 milliseconds! A magnetic pickup element on a rotating arm passed 85 pre-settable levers on a drum. The settings contained the message in a pulse variation of Morse.

Not only the tranmission time was reduced, but Kurier also introduced a new and complex system of frequency schedules and small frequency shift in the Kurier codebook. The system was to be used for Kurzsignalen and Wetterkurzsignalen, the short messages and weather reports. Although the Kurier experiment was given top priority it never became fully operational on the U-boat fleet before the end of the war. If Kurier had been operational earlier in the war, this could have been devastating for the Allied naval forces in the Atlantic. Being unable to locate U-boats by HF-DF and not monitoring the Kurzsignal messages would have deprived the codebreakers in Bletchley Park from the essential cribs to break the Naval Enigma keys.

On my website you can find the article on Kurzignalen, and I just added the new information about the Kurier system. The page also contains several images of the Kurier Kurzignal book which describes the procedures for frequency schedules and how to compose a Wetterkurzsignal or short signal weather report.

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