Munich (ship, 1927)
The Munich was a 1927 built trawler ( fishing license plate PG 465) of the fishing shipping company "Nordsee" Deutsche Hochseefischerei , Wesermünde , and operated from the home port of Geestemünde . The ship was captured by Norway in April 1940, then taken over by the Kriegsmarine in June 1940 , converted accordingly and put into service in January 1941 as weather observation ship 6 (WBS 6).
With the capture of the Munich on May 7, 1941, the Royal Navy succeeded in obtaining important German code books and instructions for setting up the Enigma cipher machine .
Destiny as a fish steamer
While the München was fishing in the Barents Sea in April 1940 , the German attack on Norway took place on April 9th . Unaware of this, the ship called at the small fishing port of Honningsvåg on the North Cape island of Magerøya on April 11 at the start of its voyage home to Germany . There it was confiscated by the local volunteer militia .
Weather observation ship
After Norway surrendered in June 1940, the ship was taken over by the Kriegsmarine, converted accordingly and put into service as weather observation ship 6 (WBS 6) in January 1941. The crew now consisted of 17 men and four meteorologists . The navy weather observation ships (WBS) had the task of delivering weather reports to the naval command and, in particular, to submarines leading to a trade war .
The weather observation ships and the Enigma
The British cryptanalyst Harry Hinsley , who worked in Bletchley Park , came to the conclusion in April 1941 that the German weather observation ships, which were lying unarmed and lonely at their positions, were using the same Enigma machines and code books as the German submarines. The WBS did not encrypt their weather reports with the Enigma, but they needed the codes to decrypt radio messages sent to them. If one could steal the code book from one of these WBS, one would be able to decipher the Enigma code of the Kriegsmarine and thus read radio messages to and from submarines and determine their positions. Although it had to be assumed that the crew of an attacked WBS would throw the currently valid Enigma settings and codes overboard, Hinsley believed that the settings would likely be locked in a safe for the following month and left there by the crew if they were would be forced to leave their ship quickly.
The raising of the Munich
The British admiralty was convinced and sent seven cruisers and destroyers to the sea area northeast of Iceland in early May 1941 . There, the destroyer Somali succeeded on May 7th in seizing the Munich and thereby capturing the Enigma settings for the month of June. This enabled the navy's radio messages to be deciphered very quickly in June.
In order to mislead the Germans and to keep the capture of the Enigma codes secret, the Munich was reported as sunk. She was sold to the Faroe Islands in 1943 and put back into service as a fishing steamer under the new name Froyen .
Aftermath
When the German naval command changed the bigram tables used in the Enigma in mid-June , it became necessary for the Royal Navy to capture the new codes. This was achieved by the destroyer Tartar , who landed the weather observation ship WBS 3 Lauenburg stationed at Jan Mayen on June 28, 1941, captured the new instructions for the plug connections and the internal setting of the Enigma machine and then sank the Lauenburg .