View source for SM UB-81

{{Other ships|German submarine U-81}}
{{Use dmy dates|date=June 2020}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image=UB 148 at sea 2.jpeg
|Ship caption=''UB-148'' at sea, a U-boat similar to ''UB-81''.
}}
{{Infobox ship career
|Ship country=[[German Empire]]
|Ship flag={{Shipboxflag|German Empire|naval}}
|Ship name=''UB-81''
|Ship ordered=23 September 1916{{sfn|Rössler|1979|p=55}}
|Ship builder=[[AG Weser]], [[Bremen]]
|Ship original cost=3,341,000 [[German Papiermark]]
|Ship yard number=281
|Ship laid down=5 January 1917<ref name=UB-81/>
|Ship launched=18 August 1917{{sfn|Gröner|1991|pp=25–30}}
|Ship completed=
|Ship commissioned=18 September 1917{{sfn|Gröner|1991|pp=25–30}}
|Ship fate=Lost 2 December 1917 after striking a mine at {{coord|50|27|N|0|53|W|display=title, inline}}{{sfn|Gröner|1991|pp=25–30}}
}}
{{Infobox ship characteristics
|Hide header=
|Header caption={{sfn|Gröner|1991|pp=25–30}}
|Ship class=[[Type UB III submarine]]
|Ship type=Coastal submarine
|Ship displacement=*{{convert|516|t|LT|lk=on|abbr=on}} surfaced
*{{convert|647|t|LT|abbr=on}} submerged
|Ship length= {{convert|55.85|m|ftin|abbr=on}} ([[o/a]])
|Ship beam={{convert|5.80|m|ft|0|abbr=on}}
|Ship draught={{convert|3.72|m|ftin|abbr=on}}
|Ship propulsion=*2 shafts
*2 × [[Körting Hannover|Körting]] six-cylinder fourstroke [[diesel engine]]s, {{convert|780|kW|bhp|abbr=on|order=flip|lk=in}}
*2 × [[Brown, Boveri & Cie]] [[Motor-generator|electric motors]], {{convert|580|kW|shp|lk=in|abbr=on}}
|Ship speed=*{{convert|13.4|kn|lk=in}} surfaced
*{{convert|7.5|kn}} submerged
|Ship range=*{{convert|8180|nmi|abbr=on|lk=in}} at {{convert|6|kn}} surfaced
*{{convert|50|nmi|abbr=on}} at {{convert|4|kn}} submerged
|Ship test depth={{convert|50|m|ft|abbr=on}}
|Ship complement=3 officers, 31 men
|Ship armament=*5 × {{convert|50|cm|in|1|abbr=on}} [[torpedo tube]]s (4 bow, 1 stern)
*10 [[torpedo]]es
*1 × [[8.8 cm SK L/30 naval gun|{{convert|8.8|cm|in|2|abbr=on}} deck gun]]
|Ship notes=
}}
{{Infobox service record
|is_ship=yes
|label=Service record
|partof=*[[Flanders Flotilla|Flandern I Flotilla]]
*11 November – 2 December 1917	
|codes=
|commanders=*''Oblt.z.S.'' [[Reinhold Saltzwedel]]<ref>{{cite Uboat.net
|id=283
|name=Reinhold Saltzwedel (Pour le Mérite)
|type=1comm
|accessdate=9 March 2015
}}</ref>
*18 September – 2 December 1917
|operations=2 patrols
|victories=*1 merchant ship sunk <br>({{GRT|3,218}})<ref name=HIT>{{cite Uboat.net
|id=ub81
|name=UB 81
|type=1boat
|accessdate=29 September 2010
}}</ref>
}}
|}

'''SM ''UB-81''''' was a German [[Type UB III submarine]] or [[U-boat]] in the [[German Imperial Navy]] ({{langx|de|Kaiserliche Marine}}) during [[World War I]]. She was [[Ship commissioning|commissioned]] into the German Imperial Navy on 18 September 1917 as SM ''UB-81''.{{#tag:ref|"SM" stands for "Seiner Majestät" ({{langx|en|His Majesty's}}) and combined with the ''U'' for ''Unterseeboot'' would be translated as ''His Majesty's Submarine''.|group=Note}}

''UB-81'' was sunk 2 December 1917 by a mine at {{coord|50|27|N|0|53|W}}, 29 crew members died in the event.{{sfn|Gröner|1991|pp=25–30}}

==Construction==
{{Main|Type UB III submarine}}
''UB-81'' was ordered by the GIN on 23 September 1916 and her keel was [[Keel laying|laid down]] on 5 January 1917.<ref name=UB-81>{{cite Uboat.net
|id=UB+81
|name=UB 81
|type=1sub
|accessdate=29 September 2010
}}</ref> She was built by [[AG Weser]] of [[Bremen]] and following just under a year of construction, [[Ceremonial ship launching|launched]] at Bremen on 4 August 1917. ''UB-81'' was [[Ship commissioning|commissioned]] later that same year under the command of [[Reinhold Saltzwedel]]. Like all Type UB III submarines, ''UB-81'' carried 10 [[torpedo]]es and was armed with a [[8.8&nbsp;cm SK L/30 naval gun|{{convert|8.8|cm|in|2|abbr=on}} deck gun]]. ''UB-81'' would carry a crew of up to 3 officer and 31 men and had a cruising range of {{convert|8180|nmi|lk=in}}. ''UB-81'' had a displacement of {{convert|516|t|LT|lk=in|abbr=on}} while surfaced and {{convert|647|t|LT|abbr=on}} when submerged. Her engines enabled her to travel at {{convert|13.4|kn|lk=in}} when surfaced and {{convert|7.5|kn}} 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.<ref>{{cite Uboat.net
|id=4208
|name=Molesey
|type=1ship
|accessdate=29 September 2010
}}</ref>

==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, Isle of Wight|Dunnose Head]]. The crew of 34, commanded by [[Oberleutnant zur See]] Reinhold Saltzwedel, managed to raise the forward [[torpedo tube]]s 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.<ref>{{cite web |url=http://uboat.net/wwi/boats/index.html?boat=UB+81 |title=UB 81|publisher=Uboat.net |access-date=12 November 2012}}</ref> She now lies at ({{coord|50|29|24|N|0|58|15|W}}) [[OSGB]] at a depth of 28 metres (92 feet).<ref>Martin Pritchard and Kendal McDonald, ''Dive Wight and Hampshire'', {{ISBN|0-946020-15-9}}</ref><ref>{{cite book |last1=McCartney |first1=Innes |title=Lost patrols : submarine wrecks of the English Channel |date=2002 |publisher=Periscope |location=Penzance |isbn=978-1-90438-104-4}}</ref> The wreck is designated as a controlled site under the [[Protection of Military Remains Act 1986]]<ref name="SI2008">{{cite web |title=The Protection of Military Remains Act 1986 (Designation of Vessels and Controlled Sites) Order 2008 | work=Office of Public Sector Information | url=http://www.opsi.gov.uk/si/si2008/uksi_20080950_en_1 | access-date=2008-07-21}}</ref> and therefore all diving on her is strictly prohibited.

==Summary of raiding history==
{| class="wikitable sortable"
|-
! width="140px"|Date
! width="140px"|Name
! width="200px"|Nationality
! width="25px" |Tonnage<ref group=Note name=tonnage>Tonnages are in [[gross register tons]]</ref>
! width="160px"|Fate<ref name=HIT/>
|-
|align="right"|30 November 1917
|align="left" |[[List of shipwrecks in November 1917#30 November|''Molesey'']]
|align="left" |{{flag|United Kingdom|civil}}
|align="right"|3,218
|align="left" |Sunk
|}

==References==

===Notes===
{{Reflist|group=Note}}

===Citations===
{{Reflist}}

== Bibliography ==
{{Refbegin}}
* {{Cite book| last = Bendert| first = Harald |title=Die UB-Boote der Kaiserlichen Marine, 1914-1918. Einsätze, Erfolge, Schicksal | location = [[Hamburg]] | publisher = [[Verlag E.S. Mittler & Sohn GmbH]]| year = 2000 | isbn = 3-8132-0713-7 | language = de}}
*{{cite book
|last1=Gröner
|first1=Erich
|last2=Jung
|first2=Dieter
|last3=Maass
|first3=Martin
|translator-last1=Thomas
|translator-first1=Keith
|translator-last2=Magowan
|translator-first2=Rachel
|year=1991
|title=German Warships 1815–1945, U-boats and Mine Warfare Vessels
|volume=2
|location=London
|publisher=Conway Maritime Press
|isbn=0-85177-593-4
|ref=CITEREFGröner1991
}}
*{{cite book |last1=Rössler |first1=Eberhard |title=Die deutschen U-Boote und ihre Werften: eine Bilddokumentation über den deutschen U-Bootbau; in zwei Bänden |date=1979 |publisher=[[Bernard & Graefe]] |location=[[Munich]] |volume=I|isbn=3-7637-5213-7|url=https://books.google.com/books?id=QIvfAAAAMAAJ |language=de}}
{{Refend}}

{{German Type UB III submarines}}
{{December 1917 shipwrecks}}

{{DEFAULTSORT:Ub081}}
[[Category:German Type UB III submarines]]
[[Category:U-boats commissioned in 1917]]
[[Category:Maritime incidents in 1917]]
[[Category:U-boats sunk in 1917]]
[[Category:World War I submarines of Germany]]
[[Category:World War I shipwrecks in the English Channel]]
[[Category:Protected wrecks of England]]
[[Category:1917 ships]]
[[Category:Ships built in Bremen (state)]]
[[Category:U-boats sunk by British warships]]
[[Category:U-boats sunk by mines]]
[[Category:1917 in Germany]]
[[Category:1917 in England]]


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