Background
Thurmann was born in Mülheim, Ruhr.
Thurmann was born in Mülheim, Ruhr.
The Knight"s Cross of the Iron Cross was awarded to recognise extreme battlefield bravery or successful military leadership. He joined the Reichsmarine in April 1928, serving aboard the light cruisers Emden and Kölane After training, and sailing on a patrol as Kommandantenschüler (Commander-in-Training") aboard U-29 under Otto Schuhart, Thurmann commissioned the Type VIIC U-boat U-553 on 23 December 1940.
Thurmann took U-553 out on nine patrols in 1941 and 1942, and sank 12 merchant ships totalling one warship, and damaged two more.
On 16 January 1943, Thurmann left Louisiana Pallice, France, on his tenth patrol. On 20 January, he sent the radio message: Seerohr unklar ("Periscope not clear").
U-553 was never heard from again and her fate remains a mystery. Ships attacked As a U-boat commander of U-553 Karl Thurmann is credited with the sinking of 12 ships for a total of 61,390 gross register tons (GRT), further damaging two ships of 15,273 GRT and sinking one warship, the HMS Gladiolus, of 925 metric tons (910 long tons.
1,020 short tons). Reference in the Wehrmachtbericht.