AType UC III submarine,UC-91 had a displacement of 491 tonnes (483 long tons) when at the surface and 571 tonnes (562 long tons) while submerged. She had alength overall of 56.51 m (185 ft 5 in), abeam of 5.54 m (18 ft 2 in), and adraught of 3.77 m (12 ft 4 in). The submarine was powered by two six-cylinder four-stroke diesel engines each producing 300 metric horsepower (220 kW; 300 shp) (a total of 600 metric horsepower (440 kW; 590 shp)), two electric motors producing 770 metric horsepower (570 kW; 760 shp), and twopropeller shafts. She had a dive time of 15 seconds and was capable of operating at a depth of 75 metres (246 ft).[4]
The submarine was designed for a maximum surface speed of 11.5 knots (21.3 km/h; 13.2 mph) and a submerged speed of 6.6 knots (12.2 km/h; 7.6 mph). When submerged, she could operate for 40 nautical miles (74 km; 46 mi) at 4.5 knots (8.3 km/h; 5.2 mph); when surfaced, she could travel 9,850 nautical miles (18,240 km; 11,340 mi) at 7 knots (13 km/h; 8.1 mph).UC-91 was fitted with six 100 centimetres (39 in) mine tubes, fourteen UC 200 mines, three 50 centimetres (20 in)torpedo tubes (one on the stern and two on the bow), seventorpedoes, and one10.5 cm (4.1 in) SK L/45 or8.8 cm (3.5 in) Uk L/30deck gun . Hercomplement was twenty-six crew members.[4]
The U-boat was ordered on 12 January 1916 and waslaunched on 19 January 1918. She wascommissioned into the German Imperial Navy on 31 July 1918 as SMUC-91.[Note 1] As with the rest of the completed UC III boats,UC-91 conducted no war patrols and sank no ships. She sank after a collision with the steamerAlexandra Woermann on 5 September 1918 in theBaltic Sea. The salvage vesselVulkan raised the wreck the following day and was repaired. She was en route to surrender on 10 February 1919 when she foundered in theNorth Sea.[5]
^Helgason, Guðmundur."WWI U-boat commanders: Bernhard Gerke".German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved20 January 2015.
Bendert, Harald (2001).Die UC-Boote der Kaiserlichen Marine 1914-1918. Minenkrieg mit U-Booten (in German). Hamburg, Berlin, Bonn: Mittler.ISBN3-8132-0758-7.
Gröner, Erich; Jung, Dieter; Maass, Martin (1991).German Warships 1815–1945, U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press.ISBN0-85177-593-4.
German Empire
