World War I Wilhelm Tranow initially worked as a radio technician aboard the battleship
Pommern. In 1914, he received a coded message, while on watch, from the cruiser
Breslau which he forwarded to fleet command, who reported they could not read it. Tranow, who was interested in codes and
cryptology, broke the
encipherment on the coded messages and forwarded the broken message back to fleet HQ. Showing a lack of urgency and understanding, Fleet HQ issued Tranow a stern warning to keep away from secret matters, instead of trying to improve the code.
Interwar period In late 1919, Tranow reconstructed Britain's enormous
Government Telegraph Code which was used by the
Admiralty to carry reports about warships. Later in the 1920s it used the broken code to enable the Germans to track British
gunboat activity on the
Yangtze. From early 1932 he started work on
Code Signaux Tactiques that provide insight into French tactics. :''I don't want to delve into high policy, but I want to say one thing: You know the English report their worldwide ship movements through these codes. Suppose their Mediterranean Fleet pours through the Straits of Gibraltar, and moves in to the Atlantic, or the Channel or even into the North Sea. Don't you want to know this in advance?'' The Kriegsmarine reconsidered their position and allowed Tranow to continue, in violation of Hitler's order. In September 1935, Tranow and his assistants made a major advance in breaking the
Royal Navy's most widely used code, the 5-digit
Naval Code (German Code Name: München (Munich)), using the method of comparing the routes of a merchant vessel, which were published in
Lloyds Weekly Shipping Reports (
Lloyd's Register), with the coded reports. Tranow's growing influence and the increasing importance of his specialty ensured his rise within
B-Dienst and eventually, sometime after 1936 he was charged with running the complete cryptanalyst section, even though he was not a
Nazi.
World War II At the start of the
war, Tranow knew the locations of all the major Fleet Forces. On 11 September 1939 this bore immediate fruit when the
B-Dienst read a British message which indicated the assembly points of
z convoy. This enabled the Kriegsmarine to dispatch a
U-boat U-31 to torpedo the
steamer Aviemore on 16 September 1939. During March 1940, Tranow and his team penetrated the
British Merchant Navy Code. Germany seized the initiative and invaded Norway on 9 April 1940. The code was read concurrently during the campaign. Exact data on British counter-measures such as landing fields, and the arrival of transports at
Harstad were known in advance, enabling German Armed Forces to take appropriate action. The breaking of the cypher enabled Tranow to read the bulk of British naval traffic until 20 August 1940, when British
Naval Cipher No. 2 (German Code Name: Köln (Cologne)) (
Naval Cypher) was introduced. From September 1941, Tranow reconstructed the codebook of Naval Cipher No. 2. In February 1942, the
B-Dienst cryptanalyst team broke the 4-digit US-British-Canadian
Convoy Cipher,
Naval Cipher No. 3 (German Code Name: Frankfurt). Around the same time, the Kriegsmarine introduced the 4-wheel version of the
Enigma which immediately rendered the Naval Enigma unreadable to
Government Code and Cypher School Bletchley Park staff of
Hut 8. enabled Tranow to make limited penetrations of British Naval Cipher No. 4 After the war, Wilhelm Tranow was such a high value individual that he was picked up by the Allied
TICOM organisation and interrogated at
Flensburg by TICOM Team 6 on 24–25 May 1945. During 1950, Wilhelm Tranow was working at the
Deutsche Presse-Agentur (). ==Notes==