Kals joined the Reichsmarine in 1924. In October 1940, after a period of service on torpedo boats and light cruisers, he transferred to the Ubootwaffe ("U-boat force"). After one patrol on U-37 under the command of Nicolai Clausen as commander in training, he took command of U-130 in June 1941. He was awarded the Knight's Cross in September 1941.[1]
In January 1943 Kals became commander of the 2nd U-boat Flotilla, based in Lorient, France. Promoted to Kapitän zur See in September 1944, he remained in this position until the end of the war.[1]
Busch, Rainer; Röll, Hans-Joachim (2003). Der U-Boot-Krieg 1939–1945 — Die Ritterkreuzträger der U-Boot-Waffe von September 1939 bis Mai 1945 [The U-Boat War 1939–1945 — The Knight's Cross Bearers of the U-Boat Force from September 1939 to May 1945] (in German). Hamburg, Berlin, Bonn Germany: Verlag E.S. Mittler & Sohn. ISBN978-3-8132-0515-2.
Fellgiebel, Walther-Peer (2000) [1986]. Die Träger des Ritterkreuzes des Eisernen Kreuzes 1939–1945 — Die Inhaber der höchsten Auszeichnung des Zweiten Weltkrieges aller Wehrmachtteile [The Bearers of the Knight's Cross of the Iron Cross 1939–1945 — The Owners of the Highest Award of the Second World War of all Wehrmacht Branches] (in German). Friedberg, Germany: Podzun-Pallas. ISBN978-3-7909-0284-6.
Scherzer, Veit (2007). Die Ritterkreuzträger 1939–1945 [The Knight's Cross Bearers 1939–1945] (in German). Jena, Germany: Scherzers Militaer-Verlag. ISBN978-3-938845-17-2.
Nazi Germany (1933-1945)
Kriegsmarine
