German submarine U-1166

German submarine U-1166 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

She was ordered on 14 October 1941, and was laid down on 4 February 1943, at Danziger Werft AG, Danzig, as yard number 138. She was launched on 28 August 1943, and commissioned under the command of Oberleutnant zur See Herbert Wagner on 8 December 1943.

Design
German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-1166 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-1166 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), one 3.7 cm Flak M42 and two 2 cm C/30 anti-aircraft guns. The boat had a complement of between forty-four and fifty-two.

Service history
On 28 July 1944, U-1166 was badly damaged in a torpedo explosion. She was later decommissioned in Kiel on 28 August 1944, and converted to a floating power station. On 3 May 1945, U-1166 was scuttled at the Deutsche Werke shipyard in Kiel off of dry dock No. 2. Her wreck was raised and broken up.