View source for HMS Excalibur

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

{{Use dmy dates|date=August 2017}}
{{Use British English|date=August 2017}}
{{more citations needed|date=June 2008}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image= Hms_excalibur_submarine.jpg
|Ship caption= HMS ''Excalibur'' (S40)
}}
{{Infobox ship career
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|Ship country=United Kingdom
|Ship flag={{shipboxflag|United Kingdom|naval}}
|Ship name=''Excalibur''
|Ship ordered=26 August 1947
|Ship awarded=
|Ship builder=[[Vickers Armstrong]]<ref>[http://www.oldships.org.uk/SHIPS/SHIP_DETAILS/EXCALIBUR_DETAIL.htm Oldships.org.uk HMS Excalibur]</ref>
|Ship original cost=
|Ship yard number=
|Ship way number=
|Ship laid down=
|Ship launched=25 February 1955
|Ship sponsor=
|Ship christened=
|Ship completed=22 February 1958
|Ship acquired=
|Ship commissioned=
|Ship recommissioned=
|Ship decommissioned=
|Ship in service=
|Ship out of service=
|Ship renamed=
|Ship reclassified=
|Ship refit=
|Ship struck=
|Ship reinstated=
|Ship homeport=
|Ship identification=[[Pennant number]]: S40
|Ship motto=
|Ship nickname=''The Excruciator''<ref>[http://www.submarineheritage.com/gallery_eclass.htm Submarine Heritage Centre]</ref>
|Ship honours=
|Ship fate=Scrapped, 1968
|Ship notes=Built at a cost of £1,142,000
|Ship badge=
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=
|Ship class={{sclass|Explorer|submarine}}
|Ship displacement=*{{convert|780|LT|t|lk=on}} (surfaced)
*{{convert|1000|LT|t}} (submerged)
|Ship length={{convert|178|ft|m|abbr=on}}
|Ship beam={{convert|15|ft|8|in|m|abbr=on}}
|Ship height=
|Ship draught={{convert|11|ft|m|abbr=on}}
|Ship depth=
|Ship power=
|Ship propulsion=*[[High Test Peroxide]] (HTP) steam raising plant driving [[steam turbine]]s (submerged)
*[[Diesel-electric]] (surfaced)
*2 shafts
|Ship speed={{convert|25|kn|lk=in}} (submerged)
|Ship range=
|Ship endurance=
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|Ship complement=41
|Ship armament=None
}}
|}
'''HMS ''Excalibur''''' was an {{sclass|Explorer|submarine}}, the sister ship of {{HMS|Explorer|submarine|6}}, the two [[submarine]]s being the only [[high-test peroxide]] (HTP) powered submarines to be constructed for the [[Royal Navy]]. She is the only commissioned ship in the Royal Navy to be named as such, in honour of the [[Excalibur|sword]] of [[King Arthur|Arthurian]] [[legend]]. In 2025, the Royal Navy christened a non-commissioned uncrewed submarine of the same name into service for the purpose of testing unmanned underwater systems.<ref>{{cite web |title=Royal Navy unveil 12 metre uncrewed submarine named after Excalibur |url=https://www.royalnavy.mod.uk/news/2025/may/15/20250515-uncrewed-submarine-naming-ceremony|access-date=16 May 2025 |website=Royal Navy |date=15 May 2025}}</ref>

==Operation==
Both ''Excalibur'' and ''Explorer'' were assigned to the 3rd Submarine Squadron although due to their experimental nature, they tended to operate independently, accompanied by their depot ship [[RFA King Salvor (A291)|HMS ''Kingfisher'']] and a fuel carrier, [[RFA Spabeck (A227)|RFA ''Spabeck'']].  They later acted as high-speed underwater targets for the Royal Navy's prototype nuclear-powered submarine {{HMS|Dreadnought|S101|6}}.

==Periscope==
[[File:Elie Golf Course Starter Hut - geograph.org.uk - 20451.jpg|thumb|left|The periscope at the golf course, used to see over an adjacent sand dune and tell if the first green is clear]]
The submarine's periscope survives. It was installed in the starter's hut at the ''Golf House Club'', the golf club at [[Elie and Earlsferry]], Scotland; players and visitors may use it to view the golf course.<ref>{{cite web |url=https://www.geograph.org.uk/photo/1003227 |title=NO4800 : Periscope in starters hut Elie Golf Course |author= Ronnie Leask |date=12 October 2008 |accessdate=19 September 2011|publisher=www.geograph.org }}
</ref>

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==References==
{{reflist}}

==Bibliography==
{{Commons category|HMS Excalibur (S40)}}
* {{Cite Colledge2006}}
*{{cite book|author1-last=Preston|author1-first=Antony|editor1-last=Chumbley|editor1-first=Stephen |title=Conway's All The World's Fighting Ships 1947–1995 |year=1995|publisher=Naval Institute Press |location= Annapolis, Maryland | isbn=1-55750-132-7|name-list-style=amp|chapter=United Kingdom |pages=95–131|author-link=Antony Preston}}
*{{cite journal |last1=Thomas |first1=Steve |title=Fire and Water: Britain's Fast Submarine Program |journal=Marine News Supplement: Warships |date=November 2022 |volume=76 |issue=11 |pages=S599–S613 |issn=0966-6958}}
{{British Explorer class submarine}}

{{DEFAULTSORT:Excalibur}}
[[Category:Explorer-class submarines]]
[[Category:Ships built in Barrow-in-Furness]]
[[Category:1955 ships]]
[[Category:Cold War submarines of the United Kingdom]]


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