SM UB-120

For other ships with the same name, see German submarine U-120.

UB-148 at sea, a U-boat similar to UB-120.
History
German Empire
Name	UB-120
Ordered	6 / 8 February 1917 [1]
Builder	AG Weser, Bremen
Cost	3,654,000 German Papiermark
Yard number	293
Laid down	17 April 1917 [2]
Launched	23 February 1918 [3]
Commissioned	23 March 1918 [3]
Fate	Surrendered 24 November 1918 [3]
General characteristics [3]
Class and type	Type UB III submarine
Displacement	512  t (504 long tons) surfaced 643 t (633 long tons) submerged
Length	55.85 m (183 ft 3 in) (o/a)
Beam	5.80 m (19 ft)
Draught	3.72 m (12 ft 2 in)
Propulsion	2 × propeller shaft 2 × Daimler four-stroke 6-cylinder diesel engines, 1,050  bhp (780 kW) 2 × Siemens-Schuckert electric motors, 780  shp (580 kW)
Speed	13.9 knots (25.7 km/h; 16.0 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	7,280  nmi (13,480 km; 8,380 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 [3]
Armament	5 × 50 cm (19.7 in) torpedo tubes (4 bow, 1 stern) 10 torpedoes 1 × 8.8 cm (3.46 in) deck gun
Service record
Part of:	III Flotilla 1 July – 11 November 1918
Commanders:	Oblt.z.S. Richard Plum [4] 23 March – 11 November 1918
Operations:	2 patrols
Victories:	1 merchant ship sunk (145  GRT)

SM UB-120 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 23 March 1918 as SM UB-120. ^{[Note 1]}

UB-120 was surrendered to the British on 24 November 1918 in accordance with the requirements of the Armistice with Germany. She was broken up in Swansea in 1922 ^[3]

Construction

Main article: Type UB III submarine

She was built by AG Weser of Bremen and following just under a year of construction, launched at Bremen on 23 February 1918. UB-120 was commissioned later the same year under the command of Oblt.z.S. Richard Plum. Like all Type UB III submarines, UB-120 carried 10 torpedoes and was armed with a 8.8 cm (3.46 in) deck gun. UB-120 would carry a crew of up to 3 officer and 31 men and had a cruising range of 7,280 nautical miles (13,480 km; 8,380 mi). UB-120 had a displacement of 512  t (504 long tons) while surfaced and 643 t (633 long tons) when submerged. Her engines enabled her to travel at 13.9 knots (25.7 km/h; 16.0 mph) when surfaced and 7.6 knots (14.1 km/h; 8.7 mph) when submerged.

Summary of raiding history

Date	Name	Nationality	Tonnage [Note 2]	Fate [5]
3 August 1918	Ludvig	Denmark	145	Sunk

References

Notes

1. "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
2. Tonnages are in gross register tons

Citations

1. Rössler 1979, p. 55.
2. Helgason, Guðmundur. "WWI U-boats: UB 120". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 13 February 2009.
3. Gröner 1991, pp. 25–30.
4. Helgason, Guðmundur. "WWI U-boat commanders: Richard Plum". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 10 March 2015.
5. Helgason, Guðmundur. "Ships hit by UB 120". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 10 March 2015.

Bibliography

• Bendert, Harald (2000). Die UB-Boote der Kaiserlichen Marine, 1914-1918. Einsätze, Erfolge, Schicksal (in German). Hamburg: Verlag E.S. Mittler & Sohn GmbH. ISBN   3-8132-0713-7.
• Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN   0-85177-593-4.
• Rössler, Eberhard (1979). Die deutschen U-Boote und ihre Werften: eine Bilddokumentation über den deutschen U-Bootbau; in zwei Bänden (in German). Vol. I. Munich: Bernard & Graefe. ISBN   3-7637-5213-7.