UB-148 at sea, a U-boat similar to UB-115.
History
German Empire
Name	UB-115
Ordered	6 / 8 February 1917[2]
Builder	Blohm & Voss, Hamburg
Cost	3,714,000 German Papiermark
Yard number	321
Launched	4 November 1917[1]
Commissioned	28 May 1918[1]
Fate	Sunk 29 September 1918 by British warships and aircraft at 55°13′N 1°22′W / 55.217°N 1.367°W / 55.217; -1.367[1]
General characteristics [1]
Class and type	German Type UB III submarine
Displacement	519 t (511 long tons) surfaced 649 t (639 long tons) submerged
Length	55.30 m (181 ft 5 in) (o/a)
Beam	5.80 m (19 ft)
Draught	3.70 m (12 ft 2 in)
Propulsion	2 × propeller shaft 2 × MAN-Vulcan four-stroke 6-cylinder diesel engines, 1,085 bhp (809 kW) 2 × AEG electric motors, 780 shp (580 kW)
Speed	13.3 knots (24.6 km/h; 15.3 mph) surfaced 7.5 knots (13.9 km/h; 8.6 mph) submerged
Range	7,420 nmi (13,740 km; 8,540 mi) at 6 knots (11 km/h; 6.9 mph) surfaced 55 nmi (102 km; 63 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	50 m (160 ft)
Complement	3 officers, 31 men[1]
Armament	5 × 50 cm (19.7 in) torpedo tubes (4 bow, 1 stern) 10 torpedoes 1 × 10.5 cm (4.13 in) deck gun
Service record
Part of:	Flandern I Flotilla 3 – 29 September 1918
Commanders:	Oblt.z.S. Reinhold Thomsen[3] 28 May – 29 September 1918
Operations:	2 patrols
Victories:	1 merchant ship sunk (336 GRT)

SM UB-115 was a German Type UB III submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. She was commissioned into the German Imperial Navy on 28 May 1918 as SM UB-115.^{[Note 1]} She was the only German submarine commissioned with the number 115.

UB-115 was sunk by British warships, including HMS Ouse and HMS Star, and the rigid airship R29 at 55°13′N 1°22′W / 55.217°N 1.367°W / 55.217; -1.367 using depth charges and aerial bombs.^[1]

Construction

She was built by Blohm & Voss of Hamburg and following just under a year of construction, launched at Hamburg on 4 November 1917. UB-115 was commissioned in the spring the next year under the command of Oblt.z.S. Reinhold Thomsen. Like all Type UB III submarines, UB-115 carried 10 torpedoes and was armed with a 8.8 cm (3.46 in) deck gun. UB-115 would carry a crew of up to 3 officer and 31 men and had a cruising range of 7,420 nautical miles (13,740 km; 8,540 mi). UB-115 had a displacement of 519 t (511 long tons) while surfaced and 649 t (639 long tons) when submerged. Her engines enabled her to travel at 13.3 knots (24.6 km/h; 15.3 mph) when surfaced and 7.4 knots (13.7 km/h; 8.5 mph) when submerged.

Fate

On 29 September 1918 while under the command of Reinhold Thomsen, UB-115 was engaged by armed trawlers (amongst others Viola), the airship R29, HMS Ouse and HMS Star. UB-115 was depth charged until destroyed and went down at position 55°14′46″N 1°22′45″W / 55.24611°N 1.37917°W / 55.24611; -1.37917 (WGS84), about 4.5 nautical miles (8.3 km; 5.2 mi) northeast of Beacon Point, Newton-by-the-Sea, off Northumberland. All 39 men aboard the submarine died in the attack and sinking.^{[4] [5]}

UB-115's wreck lies in two pieces and is covered in soft corals and an accretion formed from fly ash from a local power plant.^[4]

Summary of raiding history

Date	Name	Nationality	Tonnage[Note 2]	Fate[6]
21 September 1918	Staithes	United Kingdom	336	Sunk