SM UB-81

	UB-148 at sea, a U-boat similar to UB-81.
History
German Empire
Name	UB-81
Ordered	23 September 1916
Builder	AG Weser, Bremen
Cost	3,341,000 German Papiermark
Yard number	281
Laid down	5 January 1917
Launched	18 August 1917
Commissioned	18 September 1917
Fate	Lost 2 December 1917 after striking a mine at 50°27′N 0°53′W / 50.450°N 0.883°W
General characteristics
Class and type	Type UB III submarine
Type	Coastal submarine
Displacement	516 t (508 long tons) surfaced; 647 t (637 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 shafts; 2 × Körting six-cylinder fourstroke diesel engines, 1,050 bhp (780 kW); 2 × Brown, Boveri & Cie electric motors, 580 kW (780 shp);
Speed	13.4 knots (24.8 km/h; 15.4 mph) surfaced; 7.5 knots (13.9 km/h; 8.6 mph) submerged;
Range	8,180 nmi (15,150 km; 9,410 mi) at 6 knots (11 km/h; 6.9 mph) surfaced; 50 nmi (93 km; 58 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged;
Test depth	50 m (160 ft)
Complement	3 officers, 31 men
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:	Flandern I Flotilla; 11 November – 2 December 1917;
Commanders:	Oblt.z.S. Reinhold Saltzwedel; 18 September – 2 December 1917;
Operations:	2 patrols
Victories:	1 merchant ship sunk ; (3,218 GRT)

SM UB-81 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 18 September 1917 as SM UB-81.^{[Note 1]}

UB-81 was sunk 2 December 1917 by a mine at 50°27′N 0°53′W / 50.450°N 0.883°W / 50.450; -0.883, 29 crew members died in the event.^[3]

Construction

UB-81 was ordered by the GIN on 23 September 1916 and her keel was laid down on 5 January 1917.^[2] She was built by AG Weser of Bremen and following just under a year of construction, launched at Bremen on 4 August 1917. UB-81 was commissioned later that same year under the command of Reinhold Saltzwedel. Like all Type UB III submarines, UB-81 carried 10 torpedoes and was armed with a 8.8 cm (3.46 in) deck gun. UB-81 would carry a crew of up to 3 officer and 31 men and had a cruising range of 8,180 nautical miles (15,150 km; 9,410 mi). UB-81 had a displacement of 516 t (508 long tons) while surfaced and 647 t (637 long tons) when submerged. Her engines enabled her to travel at 13.4 knots (24.8 km/h; 15.4 mph) when surfaced and 7.5 knots (13.9 km/h; 8.6 mph) when submerged.

On the night of 30 November/1 December 1917 she torpedoed and sank the 3,218 ton British steamer Molesey 12 miles west-south-west of the Brighton Light Vessel.^[6]

Fate

UB-81 struck a mine on the night of 2 December 1917 in the English Channel to the southeast of the Isle of Wight off Dunnose Head. The crew of 34, commanded by Oberleutnant zur See Reinhold Saltzwedel, managed to raise the forward torpedo tubes above the surface and seven crewmen escaped before a collision occurred with a British patrol boat and she sank; another source claims that 35 men were aboard and that six survived. The survivors were rescued by a Royal Navy patrol boat.^[7] She now lies at (50°29′24″N 0°58′15″W / 50.49000°N 0.97083°W / 50.49000; -0.97083) OSGB at a depth of 28 metres (92 feet).^[8]^[9] The wreck is designated as a controlled site under the Protection of Military Remains Act 1986^[10] and therefore all diving on her is strictly prohibited.

Summary of raiding history

Date	Name	Nationality	Tonnage^{[Note 2]}	Fate^[5]
30 November 1917	Molesey	United Kingdom	3,218	Sunk

References

Notes

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

Citations

^ Rössler 1979, p. 55.
^ ^a ^b Helgason, Guðmundur. "WWI U-boats: UB 81". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 September 2010.
^ ^a ^b ^c ^d ^e Gröner 1991, pp. 25–30.
^ Helgason, Guðmundur. "WWI U-boat commanders: Reinhold Saltzwedel (Pour le Mérite)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 9 March 2015.
^ ^a ^b Helgason, Guðmundur. "Ships hit by UB 81". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 September 2010.
^ Helgason, Guðmundur. "Ships hit during WWI: Molesey". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 September 2010.
^ "UB 81". Uboat.net. Retrieved 12 November 2012.
^ Martin Pritchard and Kendal McDonald, Dive Wight and Hampshire, ISBN 0-946020-15-9
^ McCartney, Innes (2002). Lost patrols : submarine wrecks of the English Channel. Penzance: Periscope. ISBN 978-1-90438-104-4.
^ "The Protection of Military Remains Act 1986 (Designation of Vessels and Controlled Sites) Order 2008". Office of Public Sector Information. Retrieved 21 July 2008.

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). German Warships 1815–1945, U-boats and Mine Warfare Vessels. 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.

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[6] "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.

[tonnage-12] Tonnages are in gross register tons

[FOOTNOTERössler197955-1] Rössler 1979, p. 55.

[UB-81-2] Helgason, Guðmundur. "WWI U-boats: UB 81". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 September 2010.

[FOOTNOTEGröner199125–30-3] Gröner 1991, pp. 25–30.

[4] Helgason, Guðmundur. "WWI U-boat commanders: Reinhold Saltzwedel (Pour le Mérite)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 9 March 2015.

[HIT-5] Helgason, Guðmundur. "Ships hit by UB 81". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 September 2010.

[7] Helgason, Guðmundur. "Ships hit during WWI: Molesey". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 September 2010.

[8] "UB 81". Uboat.net. Retrieved 12 November 2012.

[9] Martin Pritchard and Kendal McDonald, Dive Wight and Hampshire, ISBN 0-946020-15-9

[10] McCartney, Innes (2002). Lost patrols : submarine wrecks of the English Channel. Penzance: Periscope. ISBN 978-1-90438-104-4.

[SI2008-11] "The Protection of Military Remains Act 1986 (Designation of Vessels and Controlled Sites) Order 2008". Office of Public Sector Information. Retrieved 21 July 2008.

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v t e Type UB III submarines
SM UB-48 SM UB-49 SM UB-50 SM UB-51 SM UB-52 SM UB-53 SM UB-54 SM UB-55 SM UB-56 SM UB-57 SM UB-58 SM UB-59 SM UB-60 SM UB-61 SM UB-62 SM UB-63 SM UB-64 SM UB-65 SM UB-66 SM UB-67 SM UB-68 SM UB-69 SM UB-70 SM UB-71 SM UB-72 SM UB-73 SM UB-74 SM UB-75 SM UB-76 SM UB-77 SM UB-78 SM UB-79 SM UB-80 SM UB-81 SM UB-82 SM UB-83 SM UB-84 SM UB-85 SM UB-86 SM UB-87 SM UB-88 SM UB-89 SM UB-90 SM UB-91 SM UB-92 SM UB-93 SM UB-94 SM UB-95 SM UB-96 SM UB-97 SM UB-98 SM UB-99 SM UB-100 SM UB-101 SM UB-102 SM UB-103 SM UB-104 SM UB-105 SM UB-106 SM UB-107 SM UB-108 SM UB-109 SM UB-110 SM UB-111 SM UB-112 SM UB-113 SM UB-114 SM UB-115 SM UB-116 SM UB-117 SM UB-118 SM UB-119 SM UB-120 SM UB-121 SM UB-122 SM UB-123 SM UB-124 SM UB-125 SM UB-126 SM UB-127 SM UB-128 SM UB-129 SM UB-130 SM UB-131 SM UB-132 SM UB-133 SM UB-136 SM UB-142 SM UB-143 SM UB-144 SM UB-145 SM UB-148 SM UB-149 SM UB-150 SM UB-154 SM UB-155
Preceded by: Type UB II Followed by: Type VII (World War II)
List of U-boats of Germany

v t e Shipwrecks and maritime incidents in December 1917
Shipwrecks	1 Dec: Washington 2 Dec: SM UB-81 6 Dec: USS Jacob Jones, Mont-Blanc, SM UC-69 7 Dec: CGS Simcoe 8 Dec: USS Rush 9 Dec: SM UB-18 10 Dec: SM UB-75, SMS Wien 12 Dec: USS Elizabeth, HMS Partridge, HMS Wolverine, Florida 13 Dec: SM U-75, HMS Stephen Furness 14 Dec: Châteaurenault, SM UC-38 17 Dec: USS F-1 18 Dec: Mariposa 19 Dec: SM UB-56 24 Dec: HMS Penshurst 25 Dec: Ajax, Espagne, SM U-87 30 Dec: HMT Aragon, HMS Attack 31 Dec: USS Fli-Hawk, Vigrid, HMS Osmanieh
Other incidents	6 Dec: Halifax Explosion, Imo, Stella Maris, SM U-96 17 Dec: USS F-3 Unknown date: HMS Carysfort
1916 1917 1918 November 1917 January 1918