SM UB-107

History
German Empire
Name:	UB-107
Ordered:	6/8 February 1917[1]23 September 1913
Builder:	Blohm & Voss, Hamburg
Cost:	3,714,000 German Papiermark
Yard number:	313
Launched:	21 July 1917[2]
Commissioned:	16 February 1918[2]
Fate:	sunk 27 July 1918 by British warships at 54°23′N 0°24′W / 54.383°N 0.400°WCoordinates: 54°23′N 0°24′W / 54.383°N 0.400°W.[2]
General characteristics [2]
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 (19.0 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 × Siemens-Schuckert 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[2]
Armament:	5 × 50 cm (19.7 in) torpedo tubes (4 bow, 1 stern) with 10 torpedoes 1 × 8.8 cm (3.46 in) deck gun
Service record[3]
Part of:	Flandern II Flotilla 16 May – 4 August 1918
Commanders:	Kptlt. Hans Howaldt 16 February – 16 May 1918 Kptlt. Eberhard von Prittwitz und Gaffron 17 May – 4 August 1918
Operations:	4 patrols
Victories:	11 merchant ships sunk (26,147 GRT) 1 merchant ship damaged (1,685 GRT)

SM UB-107 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 16 February 1918 as SM UB-107.^{[nb 1]}

The submarine conducted 4 patrols and sank 11 ships during the war for a total loss of 26,147 GRT. UB-107 was sunk on 27 July 1918 by HMS Vanessa and HMT Calvis at 54°23′N 0°24′W / 54.383°N 0.400°W.^[2]

Construction

UB-107 was ordered by the GIN on 23 September 1916. She was built by Blohm & Voss of Hamburg and following just under a year of construction, launched at Hamburg on 21 July 1917. UB-107 was commissioned early the next year . Like all Type UB III submarines, UB-107 carried 10 torpedoes and was armed with a 8.8 cm (3.46 in) deck gun. UB-107 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-107 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

The first recorded fate of UB-107 was noted as sunk by depth charge on July 27, 1918 by the Royal Navy trawler Calvis and HMY Vanessa II at position 57°23′N 00°24′W / 57.383°N 0.400°W. It has since been argued that the UB-107 was probably not present for the attack by Calvis and Vanessa II as it was the only U-boat that could have been responsible for the sinking of steamers Chloris and John Rettig two and a half hours later at position 53°52′N 00°10′E / 53.867°N 0.167°E.

In 1985 divers discovered the wreck of UB-107 one mile north of Flamborough Head at position 54°08′N 00°00′W / 54.133°N -0.000°E entangled with another wreck, the SS Malvina, a British steamer torpedoed and sunk on 3 August 1918 by UB-104. UB-107 was identified by the markings on her propellers.^[4][5] It is suggested that either UB-107 suffered an accident of some sort or was lost on a British mine between July 28 and August 3, 1918 leaving all hands lost (38 dead).^[3]

Summary of raiding history

Date	Name	Nationality	Tonnage (GRT)	Fate[6]
10 May 1918	Erich Lea	Norway	1,630	Sunk
10 May 1918	Naparima	Sweden	1,685	Damaged
6 June 1918	Koningin Regentes	Netherlands	1,970	Sunk
8 June 1918	Hogarth	United Kingdom	1,231	Sunk
13 June 1918	Agnes	Sweden	1,334	Sunk
13 June 1918	Kalo	United Kingdom	1,957	Sunk
15 June 1918	Kieldrecht	United Kingdom	1,284	Sunk
8 July 1918	Chicago	United Kingdom	7,709	Sunk
8 July 1918	War Crocus	United Kingdom	5,296	Sunk
9 July 1918	Fryken	Sweden	943	Sunk
27 July 1918	Chloris	United Kingdom	984	Sunk
27 July 1918	John Rettig	Sweden	1,809	Sunk

Television Documentary

The fate of UB-107 was the subject of an episode of the documentary television series Deep Sea Detectives: "Mystery U-Boat of WWI". The documentary offered various scenarios for the sinking based on historical evidence and exploratory diving at the wreck site.^[7]

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.

References

1. Rössler 1979, p. 66.
2. Gröner 1991, pp. 25-30.
3. Helgason, Guðmundur. "WWI U-boats: UB 107". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 8 December 2014.
4. "UB-107 (Wreck)". wikimapia.org. Retrieved 2009-10-07.
5. "100 Best Wreck Dives THE MALVINA AND UB-107 – 49". divernet.com. Retrieved 2009-10-07.
6. Helgason, Guðmundur. "Ships hit by UB 107". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 8 December 2014.
7. http://www.tv.com/shows/deep-sea-detectives/mystery-u-boat-of-world-war-i-1066625/

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 2. Translated by Thomas, Keith; Magowan, Rachel (London: Conway Maritime Press). ISBN 0-85177-593-4.
• Rössler, Eberhard (1979). U-Bootbau bis Ende des 1. Weltkrieges, Konstruktionen für das Ausland und die Jahre 1935 – 1945. Die deutschen U-Boote und ihre Werften (in German) I (Munich: Bernard & Graefe). ISBN 3-7637-5213-7.