View source for HMS A7

{{short description|Submarine of the Royal Navy}}

{{Use dmy dates|date=February 2018}}
{{Use British English|date=February 2018}}
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|Ship image=HMS A7.jpg
|Ship caption=HMS ''A7''
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|Ship country=United Kingdom
|Ship flag={{shipboxflag|United Kingdom|naval}}
|Ship name=HMS ''A7''
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|Ship ordered=
|Ship awarded=
|Ship builder=[[Vickers]] [[Barrow-in-Furness]]
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|Ship laid down=19 February 1903
|Ship launched=23 January 1905
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|Ship commissioned=16 January 1905
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|Ship fate=Sunk in Whitsand Bay, 16 January 1914
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{{Infobox ship characteristics
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|Header caption=
|Ship class={{sclass2|A|submarine (1903)|0}} [[submarine]]
|Ship displacement=*{{convert|190|LT|t|0|abbr=on}} surfaced
*{{convert|206|LT|t|0|abbr=on}} submerged
|Ship length={{convert|105|ft|m|abbr=on|1}}
|Ship beam={{convert|12|ft|9|in|m|abbr=on|1}}
|Ship height=
|Ship draught={{convert|10|ft|8|in|m|abbr=on|1}}
|Ship depth=
|Ship power=*{{convert|550|bhp|lk=in|abbr=on}} ([[petrol engine]])
*{{convert|150|hp|abbr=on}} ([[electric motor]])
|Ship propulsion=*1 × 16-cylinder Wolseley petrol engine
*1 × electric motor
|Ship speed=*{{convert|11|kn|lk=in}} surfaced
*{{convert|7|kn}} submerged
|Ship range={{convert|500|nmi|lk=in}} at {{convert|10|kn|abbr=on}} surfaced
|Ship test depth=
|Ship complement=2 officers and 9 ratings
|Ship armament=2 × [[British 18 inch torpedo|18-inch (45&nbsp;cm)]] [[torpedo tube]]s
}}
|}

'''HMS ''A7''''' was an {{sclass2|A|submarine (1903)|0}} [[submarine]] built for the [[Royal Navy]] in the first decade of the 20th century. She sank in a training accident in 1914 with the loss of her entire crew. Efforts to [[Marine salvage|salvage]] her failed and her wreck is a protected site. Diving on her is prohibited without a licence from the [[Ministry of Defence (United Kingdom)|Ministry of Defence]].

==Design and description==
''A7'' was a member of the [[A-class submarine (1903)|first British class of submarines]], although slightly larger, faster and more heavily armed than the [[lead ship]], {{HMS|A1}}. The submarine had a length of {{convert|105|ft|1|in|m|1}} [[length overall|overall]], a [[beam (nautical)|beam]] of {{convert|12|ft|9|in|m|1}} and a mean [[draft (ship)|draft]] of {{convert|10|ft|8|in|m|1}}. They [[displacement (ship)|displaced]] {{convert|190|LT|t}} on the surface and {{convert|206|LT|t}} submerged. The A-class submarines had a crew of 2 officers and 9 [[Naval rating|ratings]].<ref name=gg9>Gardiner & Gray, p. 86</ref>

For surface running, the boats were powered by a single 16-cylinder {{convert|550|bhp|lk=in|0|adj=on}} [[Wolseley Motors|Wolseley]] [[petrol engine]] that drove one [[propeller shaft]]. When submerged the propeller was driven by a {{convert|150|hp|0|adj=on}} [[electric motor]]. They could reach {{convert|11|kn|lk=in}} on the surface and {{convert|7|kn}} underwater.<ref name=gg9/> On the surface, ''A7'' had a range of {{convert|500|nmi|lk=in}} at {{convert|10|kn}}; submerged the boat had a range of {{convert|30|nmi|lk=in}} at {{convert|5|kn}}.<ref name=a0>Akermann, p. 120</ref>

The boats were armed with two [[British 18 inch torpedo|18-inch (45&nbsp;cm)]] [[torpedo tube]]s in the bow. They could carry a pair of reload torpedoes, but generally did not as doing so that they had to compensate for their weight by an equivalent weight of fuel.<ref>Harrison, Chapter 27</ref>

==Construction and career==
''A7'' was ordered as part of the 1903–04 Naval Programme from at [[Vickers]].<ref>Harrison, Chapter 3</ref> She was laid down at their [[shipyard]] in [[Barrow-in-Furness]] on 1 September 1903, [[Ship naming and launching|launched]] on 21 January 1905 and completed on 13 April.<ref name=a0/> She sank in [[Whitsand Bay]], [[Cornwall]] on 16 January 1914 with the loss of her crew whilst carrying out dummy [[torpedo]] attacks on {{HMS|Pygmy||2}} in conjunction with submarine {{HMS|A9||2}}. A disturbance in the water was seen which thought to be caused by the crew of ''A7'' attempting to blow water from her ballast tanks in a desperate attempt to reach the surface.<ref name="Holt, Chapter 7">Holt, Chapter 7</ref>  The location was marked with a buoy and ''Pygmy'' returned to [[Plymouth Sound]] to report on the disaster. ''Pygmy'' returned to the site in the afternoon but was unable to locate the buoy as the weather had deteriorated.  It then took five days to relocate the submarine, she was found in {{convert|121|ft|m|abbr=on}} depth with {{convert|20|ft|m|abbr=on}} of her stern buried in the muddy seabed and with her bow {{convert|33|ft|m|abbr=on}} off the bottom, raised at an angle of 30°.<ref name="Holt, Chapter 7"/>  Several attempts were made to salvage her over the next month by attaching a hawser to the towing eye on the [[Bow (ship)|bow]] or wrapping steel hawsers around her hull, but her [[stern]] was too deeply embedded in the mud and the hawsers parted without pulling her out. She lies today where she sank, buried up to her waterline in a flat, mud seabed in about {{convert|121|ft|m|abbr=on}} of water. In 2001, she was declared as one of 16 wrecks in [[United Kingdom|British]] waters designated as "Controlled Sites" under the [[Protection of Military Remains Act]] by the [[British Government]] and which cannot be dived without special permission.

In 2014 the SHIPS Project team in Plymouth completed an archaeological investigation of the A7 submarine, having been granted a licence by the UK Ministry of Defence.<ref>Holt, Chapter 1</ref>

==Notes==
{{Reflist|30em}}

==References==
* {{cite book|last=Akermann|first=Paul|title=Encyclopaedia of British Submarines 1901–1955|edition=reprint of the 1989|year=2002|publisher=Periscope Publishing|location=Penzance, Cornwall|isbn=1-904381-05-7}}
* {{Cite Colledge2006}}
* {{cite book |editor1-last=Gardiner|editor1-first=Robert|editor2-last=Gray|editor2-first=Randal|title=Conway's All the World's Fighting Ships 1906–1921|year=1985|location=Annapolis, Maryland|publisher=Naval Institute Press|isbn=0-85177-245-5|name-list-style=amp}}
* {{cite web|url=http://rnsubs.co.uk/dits-bits/br-3043.html |title=The Development of HM Submarines From Holland No. 1 (1901) to Porpoise (1930) (BR3043) |last=Harrison |first=A. N. |date=January 1979 |publisher=RN Subs |accessdate=27 September 2022}}
*{{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}}
* {{cite book|last=Holt|first=Peter|title=HM Submarine A7, An Archaeological Assessment, BAR British Series no. 613, Oxford |isbn=978-1407-31374-0|year=2015}}

==External links==
*[http://www.maritimequest.com/warship_directory/great_britain/submarines/pages/a_1902_class/a_7_page_1.htm MaritimeQuest HMS A-7 Pages]
*[http://www.maritimequest.com/warship_directory/great_britain/submarines/pages/a_1902_class/a_7_roll_of_honour.htm HMS A-7 Roll of Honour]
*{{cite web | url = http://www.maritimequest.com/warship_directory/great_britain/submarines/pages/class_overviews/a_class_1902.htm | title = A Class (1902) Submarines Class Overview |work = Maritime Quest | accessdate=2007-08-06}}
*[http://www.opsi.gov.uk/si/si2008/uksi_20080950_en_1 SI 2008/950] Designation under the Protection of Military Remains Act 1986
*[https://web.archive.org/web/20180108023935/http://www.submarine-museum.co.uk/what-we-have/memorial-chapel/submarine-losses?start=2 'Submarine losses 1904 to present day' - Royal Navy Submarine Museum]
*[http://www.promare.co.uk/a7project/index.htm The A7 Project - an archaeological investigation of HM submarine A7] {{Webarchive|url=https://web.archive.org/web/20160208200109/http://www.promare.co.uk/a7project/index.htm |date=8 February 2016 }}

{{A class submarine (1903)}}
{{January–July 1914 shipwrecks}}
{{Coord|50|19|45|N|04|18|25|W|display=title}}

{{DEFAULTSORT:A07}}
[[Category:A-class submarines (1903)]]
[[Category:Protected wrecks of the United Kingdom]]
[[Category:1914 disasters in the United Kingdom]]
[[Category:British submarine accidents]]
[[Category:Shipwrecks in the English Channel]]
[[Category:Maritime incidents in January 1914]]
[[Category:Ships built in Barrow-in-Furness]]
[[Category:Royal Navy ship names]]
[[Category:1905 ships]]