German submarine U-865

German submarine U-865 was a Type IXC/40 U-boat of Nazi Germany's Kriegsmarine built for service during the Second World War. She was laid down in Bremen, Germany on 5 January 1943, and launched on 12 July 1943.

Design
German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-865 had a displacement of 1144 t when at the surface and 1257 t while submerged. The U-boat had a total length of 76.76 m, a pressure hull length of 58.75 m, a beam of 6.86 m, a height of 9.60 m, and a draught of 4.67 m. The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4400 PS for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1000 shp for use while submerged. She had two shafts and two 1.92 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 18.3 kn and a maximum submerged speed of 7.3 kn. When submerged, the boat could operate for 63 nmi at 4 kn; when surfaced, she could travel 13850 nmi at 10 kn. U-865 was fitted with six 53.3 cm torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm SK C/32 naval gun, 180 rounds, and a 3.7 cm Flak M42 as well as two twin 2 cm C/30 anti-aircraft guns. The boat had a complement of forty-eight.

Service history
She had one commander, Oberleutnant zur See Dietrich Stellmacher, for her two patrols. She had a crew complement of 59.

She did not sink any shipping on her two patrols, and went missing after leaving Trondheim in Norway on 9 September 1944, with all hands lost.

In late June/ early July 1944, she was attacked by an RAF B-24 Liberator, which did some damage to her, however she in turn did some damage to the attacking aircraft with the submarine's flak gun, setting the aircraft on fire. Both the U-boat and aircraft were forced to return to their respective bases.