Career
He commanded the U-boats U-61 and U-106, and then served as a staff officer before returning to command U-861. He sank nineteen ships for a total of 101,744 gross register tons (GRT), and damaged four others for 51,668 GRT to become number 29 on the list of the highest scoring U-Boat aces of World World War World War II Born in Grunewald, Berlin, Oesten joined the Reichsmarine in April 1933. After serving aboard the cruisers Admiral Graf Spee and Karlsruhe he transferred to the U-boat arm in May 1937, and was appointed watch officer of U-20.
World World War II = U-61 In August 1939 Oesten commissioned U-61, sailing on nine patrols, and sinking five ships.
= U-106 Taking command of U-106 in September 1940, he sailed on three patrols sinking another ten ships. On 20 March 1941 during an attack on convoy SL-68 he damaged the British battleship HMS Malaya.
= 9th Flotilla In October 1941 Oesten became the first commander of the 9th U-boat Flotilla based in Brest, France. In March 1942 he joined the staff of FdU Nordmeer directing the U-boat war in the Norwegian Sea.
= U-861 In September 1943 Oesten returned to active duty in U-861, sailing first to Brazilian waters where he sank another two ships and then around the Cape of Good Hope to join the Monsun Gruppe of U-boats operating in the Indian Ocean.
He sank another two ships, bringing his career total to 19 ships sunk, totalling 101,744 GRT, and four ships damaged (51,668 GRT), before reaching Penang on 23 September 1944. U-861 left Soerabaya, Dutch East Indies, in January 1945 carrying a cargo of vital materials, but only two torpedoes, and reached Trondheim, Norway, in April, just before the German surrender. Post War Oesten was a technical advisor for the 2005 submarine simulator Silent Hunter III. Ships attacked As a U-boat commander of U-61, U-106 and U-861 Oesten is credited with the sinking of 18 ships for a total of 100,007 gross register tons (GRT) and one auxiliary warship 1,737 GRT. He further damaged three ships of 20,568 GRT and one warship, the HMS Malaya, of 31,100 metric tons (30,600 long tons.
34,300 short tons).
Spanish Cross in bronze without swords (6 June 1939) Wehrmachtbericht reference.
