SM UB-109

SM UB-109 was a German Type UB III submarine or U-boat in the German Imperial Navy (Kaiserliche Marine) during World War I. She was commissioned into the German Imperial Navy on 31 December 1917 as SM UB-109.

UB-109 was sunk by mine in the English Channel on 29 August 1918 and underwater scanning of the area covered by the Dover Barrage shows her wreck broken in half.

Construction
She was built by Blohm & Voss of Hamburg and following just under a year of construction, launched at Hamburg on 7 July 1917. UB-109 was commissioned later the same year under the command of Oblt.z.S. Kurt Ramien. Like all Type UB III submarines, UB-109 carried 10 torpedoes and was armed with a 8.8 cm deck gun. UB-109 would carry a crew of up to 3 officer and 31 men and had a cruising range of 7,420 nmi. UB-109 had a displacement of 510 t while surfaced and 629 t when submerged. Her engines enabled her to travel at 13.3 kn when surfaced and 7.4 kn when submerged.