German submarine U-1171

German submarine U-1171 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

She was ordered on 16 July 1942, and was laid down on 5 May 1943 at Danziger Werft AG, Danzig, as yard number 143. She was launched on 23 November 1943 and commissioned under the command of Oberleutnant zur See Otto Heinrich Nachtigall on 22 March 1944.

Design
German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-1171 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, an overall beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two SSW GU 343/38-8 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-1171 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes or 26 TMA or TMB Naval mines, one 8.8 cm SK C/35 naval gun, 220 rounds, and an anti-aircraft gun. The boat had a complement of between forty-four and fifty-two.

Service history
On 9 May 1945, U-1171 surrendered at Stavanger, Norway, before participating in any war patrols. She was later transferred to Lisahally on 27 May 1945. U-1171 would be spared, for a time, becoming a British N-class submarine, N19, used for testing and then in April 1949, broken up at Sunderland.