Timm joined the Kriegsmarine in October 1933. He first served as a junior officer aboard the minesweepers M-132 and M-110, before taking command of M-7 in July 1939. His first success came on 9 January 1940 when he attacked the Royal Navy's submarine with depth charges in the Heligoland Bight, then forcing her to the surface and then being scuttled. Timm won the Iron Cross during the Norwegian invasion in May 1940, and then he transferred into the U-boat fleet. After U-Boat commander's training at Pillau, in September 1941 Timm took command of the new Type VIIC U-boat. After training missions in the Baltic Sea, the U-251 was assigned to the 11th U-boat Flotilla, which was based at Bergen, Norway, in April 1942. Timm next commanded nine war patrols into the Arctic Sea, on the prowl against the arctic convoys of World War II to the northern seaports of the Soviet Union. There, the U-251 sank two merchant ships: The first one, on 3 May 1942, was the 6,135 ton Britishmerchant ship SS Jutland of Convoy PQ-15, while the second, in July 1942, was the American cargo ship from the ill-fated Convoy PQ 17. Timm also took part in "Operation Wunderland" in the Kara Sea, surfacing close to Uyedineniya Island and destroying a Soviet weather station with cannon fire from his deck gun. When the U-251 was decommissioned to be overhauled in June 1943, Timm and his crew were sent to take over the new Type IXD2 U-boat, and after training missions in the Baltic Sea, they sailed her to the Indian Ocean during mid-1944 to join the Monsun Gruppe of U-boats prowling in the Indian Ocean and farther east, from Japanese-held naval bases. The U-862 sank five merchantmen and also shot down a British Catalina flying boat of No. 265 Squadron RAF while en route. On 5 July, Timm received notification of his promotion to Korvettenkapitän. Then, while patrolling off eastern Australia in late 1944 and early 1945, Timm sank two American Liberty ship merchantmen. In January 1945, the U-862 entered and departed from the Port of Napier, New Zealand, undetected. This later gave rise to the widely circulated post-war "tall tale" that Timm led members of his crew ashore near Napier in order to milk some cows to supplement their meagre rations. After the surrender of Nazi Germany on May 7, 1945, all of the German U-boat crews in the Far East were interned by the Japanese Empire at Singapore and Batu Pahat, and their U-boats were confiscated by the Imperial Japanese Navy. The U-862 was commissioned into the Japanese Navy as the I-502. Korvettenkapitän Timm and his crewmen were still being held in Singapore when units of the Royal Navy arrived there on September 12, 1945. The German seamen were taken into custody by the British, and they were taken to Great Britain during July 1946, and then still held prisoner, even though Nazi Germany had surrendered over a year earlier. Timm was finally released from British captivity in April 1948.
Timm's Postwar Activities
Timm joined the new West German navy, the Bundesmarine, when it was established in 1956. Timm served in several positions, including that of the first commander of the West German frigate Scharnhorst. Timm finally retired from the Bundesmarine in 1966 with the rank of Fregattenkapitän.
