German submarine U-3505
German submarine "U-3505" was a Type XXI submarine of Nazi Germany's "Kriegsmarine" during World War II. The U-boat was laid down on 9 July 1944 at the Schichau-Werke yard at Danzig, launched on 25 August 1944, and commissioned on 7 October 1944 under the command of "Oberleutnant zur See" Horst Willner. Design. Like all Type XXI U-boats, "U-3505" had a displacement of when at the surface and while submerged. She had a total length of (o/a), a beam of , and a draught of . The submarine was powered by two MAN SE supercharged  six-cylinder M6V40/46KBB diesel engines each providing , two Siemens-Schuckert GU365/30 double-acting electric motors each providing , and two Siemens-Schuckert silent running GV232/28 electric motors each providing . The submarine had a maximum surface speed of and a submerged speed of . When running on silent motors the boat could operate at a speed of . When submerged, the boat could operate at for ; when surfaced, she could travel at . "U-3505" was fitted with six torpedo tubes in the bow and four C/30 anti-aircraft guns. She could carry twenty-three torpedoes or seventeen torpedoes and twelve mines. The complement was five  officers and fifty-two men. Service history. Although never used in combat, the submarine achieved some degree of fame due to a rescue mission. Her commander, Captain Horst Willner, disguised his wife as a sailor and smuggled her aboard together with their three-month-old baby (a crime punishable by death). The captain's family was originally to be evacuated on , joining a flood of refugees fleeing East Prussia ahead of the advancing Red Army, in "Operation Hannibal". Willner cancelled their places and took them onto his submarine, and so probably saved their lives since "Gustloff" was sunk by the  with the greatest loss of life in maritime history. After leaving Danzig they went to Gotenhafen, where they took on board 110 children and adolescents. The refugees, including the captain's family, were safely delivered at Travemünde, Lübeck, on 2 April 1945. Returning to Kiel, "U-3505" was to participate in torpedo exercises, but on 3 April was sunk in a bombing raid while in harbour. At least one sailor was killed.