SM UC-109

SM UC-109 was a German Type UC III minelaying submarine or U-boat built for the German Imperial Navy (Kaiserliche Marine) during World War I.

Design
A Type UC III submarine, UC-100 had a displacement of 491 t when at the surface and 571 t while submerged. She had a length overall of 56.51 m, a beam of 5.54 m, and a draught of 3.77 m. The submarine was powered by two six-cylinder four-stroke diesel engines each producing 300 PS (a total of 600 PS), two electric motors producing 770 PS, and two propeller shafts. She had a dive time of 15 seconds and was capable of operating at a depth of 75 m.

The submarine was designed for a maximum surface speed of 11.5 kn and a submerged speed of 6.6 kn. When submerged, she could operate for 40 nmi at 4.5 kn; when surfaced, she could travel 9850 nmi at 7 kn. UC-100 was fitted with six 100 cm mine tubes, fourteen UC 200 mines, three 50 cm torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 10.5 cm SK L/45 or 8.8 cm Uk L/30 deck gun. Her complement was twenty-six crew members.

Construction and career
The U-boat was launched on 2 June 1918 and completed on 4 December 1918. Because UC-109 was finished after the end of fighting, she was never commissioned into the German Imperial Navy; had she been so commissioned, she would have been named SM UC-109. UC-109 was awarded to the United Kingdom as a war reparation and broken up in 1921.