View source for Amphion-class submarine

{{Short description|Class of diesel-electric submarines of the Royal Navy}}
{{For|other ship classes of the same name|Amphion class (disambiguation){{!}}Amphion class|Acheron class (disambiguation){{!}}Acheron class}}
{{more citations needed|date=February 2013}}
{{Use dmy dates|date=May 2020}}
{|{{Infobox ship begin}}
{{Infobox ship image
| Ship image = HMS Alliance S67.jpg
| Ship caption = {{HMS|Alliance}} at Gosport submarine museum
}}
{{Infobox ship class overview
| Name = 
| Builders = *[[Vickers Armstrong]], [[Barrow-in-Furness]]
*[[Cammell Laird]], [[Birkenhead]]
*Scotts of [[Greenock]]
*HM Dockyard, [[Chatham, Medway|Chatham]]
| Operators = {{navy|United Kingdom}}
| Class before = [[British V-class submarine|V class]]
| Class after = {{sclass|Explorer|submarine|4}}
| Subclasses = 
| Cost = 
| Built range = 
| In service range = 1945 - 1974
| In commission range = 
| Total ships building = 
| Total ships planned = 46
| Total ships completed = 16
| Total ships cancelled = 30
| Total ships active = 
| Total ships laid up = 
| Total ships lost = 
| Total ships retired = 
| Total ships preserved = 1
}}
{{Infobox ship characteristics
| Hide header = 
| Header caption = 
| Ship type = [[Submarine]]
| Ship displacement = 1,385&nbsp;tons surfaced, 1,620&nbsp;tons submerged
| Ship length = {{convert|280.5|ft|m|abbr=on}}
| Ship beam = {{convert|22.3|ft|m|abbr=on}}
| Ship height = 
| Ship draught = {{convert|16.8|ft|m|abbr=on}}
| Ship power = 
| Ship propulsion = 
| Ship speed = *{{convert|18.5|kn|km/h}} surfaced
*{{convert|8|kn|km/h}} submerged
| Ship range = *{{convert|10500|nmi|km}} at {{convert|11|kn|km/h}} surfaced
*{{convert|16|nmi|km}} at {{convert|8|kn|km/h}} submerged
| Ship endurance = 
| Ship test depth = {{convert|500|ft|m}}
| Ship complement = 61 officers and men
| Ship sensors = 
| Ship EW = 
| Ship armament = *6 × [[British 21 inch torpedo|21 inch (533 mm)]] bow torpedo tubes (2 external, one-shot, later removed)
* 4 × {{convert|21|in|mm|abbr=on|0}} stern torpedo tubes (2 external, one-shot, later removed)
*16 torpedoes or 26 mines carried internally
*1 × QF {{convert|4|in|mm|abbr=on|0}} gun ([[QF 4 inch naval gun Mk IV, XII, XXII|Mk XXII]] or [[QF 4 inch naval gun Mk XXIII|Mk XXIII]])
*1 × one [[Oerlikon 20 mm cannon|Oerlikon 20&nbsp;mm cannon]]
*3 × .303-caliber machine guns
| Ship armour = 
| Ship notes = 
}}
|}

The '''''Amphion'' class''' (also known as the '''"A" class''' and '''''Acheron'' class''') of [[United Kingdom|British]] [[Submarine#Diesel-electric transmission|diesel-electric]] [[submarine]]s were designed for use in the [[Pacific War]]. Only two were completed before the end of hostilities, but following modernisation in the 1950s, they continued to serve in the [[Royal Navy]] into the 1970s.

==Development and service==
[[File:Avenger AS3 over HMS Artful.jpeg|thumb|left|{{HMS|Artful|P456|6}} in the mid-1950s, showing the original profile of the class before they were reconstructed.]]
The ''Amphion'' class were ordered by the British Admiralty in 1943, upon the realisation that the new Pacific theatre of war following the [[attack on Pearl Harbor]] needed a new type of submarine. They were originally designed to replace the [[British S-class submarine (1931)|S-class]] and [[British T-class submarine|T-class]] submarines, which were too slow and unable to dive deep enough to be suited to Pacific waters during [[World War II]]. They were essentially the same size as the T class,<ref>{{Cite book|title=Design and Construction of British Warships 1939-1945, Volume II, The Official Record|last=Brown|first=DK|publisher=Naval Institute Press|year=1966|isbn=1-55750-161-0|pages=27, 34}}</ref> arranged for fast, simple construction and to utilize much of the materials and equipment set aside for the T boats. They had a high, flared bow for excellent sea performance and had effective air conditioning, essential for [[Far East]] submarine operations. They were operated by a crew of between 60 and 68.

Originally, 46 submarines were ordered, but only 18 were [[ship naming and launching|launched]] (10 by [[Vickers-Armstrong]] in [[Barrow-in-Furness]]) and 16 [[ship commissioning|commissioned]], the other two hulls being used for crush testing. The class was designed for quick construction, using an entirely welded hull which could be fabricated in sections, a technique new to Britain but standard for [[Nazi Germany]]'s [[U-boat]]s. Each submarine took about 8 months from keel-laying to launching, compared with around 15 months for the earlier T class, but only two of the boats were completed before the end of the war: {{HMS|Amphion|P439|2}}, launched in August 1944, and {{HMS|Astute|P447|2}} in January 1945; neither saw action.

The ''Amphion'' class was one of only two new British submarine designs produced during World War II, the other being the [[X-class submarine|X-craft]] 4-man submarines.  Wartime experience had shown that submarines had to operate further from the United Kingdom and with larger patrol areas than had been foreseen—in the [[Far East]] and [[Mediterranean]] for example—so the faster and slightly larger A class was designed to have a longer range than the T class, with accommodation suitable for longer missions.

After World War II various modifications were made to these Overseas Patrol Submarines, as they were known. A [[Submarine snorkel|snort mast]] based on the ''schnorkel'' used by U-boats during the war, a radar which could be used from periscope depth, and a night periscope were added to the A- and surviving T-class submarines.

In response to the start of the [[Cold War]] in the early 1950s their target changed from surface ships to [[Soviet]] submarines. In January 1948 the primary operational function of the British submarine fleet was announced to be interception of Soviet submarines slipping out of their bases in Northern Russia, potentially to attack British and Allied merchant vessels. The following April Assistant Chief of Naval Staff Rear-Admiral [[Geoffrey Oliver]] circulated a paper in which he proposed that British submarines take a more offensive role, attacking Soviet submarines off the Northern Russian coast and mining the waters in the area. With the dramatically reduced surface fleet, he commented that this was one of the few methods the Royal Navy had for "getting to the enemy on his home ground".<ref>{{cite book | title = The T-Class submarine| isbn = 0-85368-958-X | publisher = Arms and Armour | author = Paul Kemp | year = 1990 | page = 127}}</ref>

The A and T classes were refitted for their new role between 1955 and 1960 with a complete rebuild of the forward and after hull section, lengthening and streamlining of the upper decks and conning towers, removal of deck guns to improve underwater speed and noise, removal of external torpedo tubes, and greatly improved [[sonar]]. When {{HMS|Affray|P421|2}} was lost in 1951 all the ''Amphion'' class were briefly confined to port pending investigation into her loss.

During the [[Indonesia–Malaysia confrontation]] in the mid-1960s, some ''Amphion''-class submarines were fitted with either a [[QF 4 inch naval gun Mk XXIII|QF 4-inch Mk XXIII gun]] or a single 20mm autocannon to counter blockade running [[Junk (ship)|junk]]s. They were the last British submarines to carry a [[deck gun]].<ref>{{cite web|url=http://www.rnsubs.co.uk/Boats/BoatDB2/index.php?BoatID=560 |title=Boat Database - Andrew |website=www.rnsubs.co.uk |publisher=The Barrow-in-Furness Branch of the Submariners Association |access-date=20 March 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140320221648/http://www.rnsubs.co.uk/Boats/BoatDB2/index.php?BoatID=560 |archive-date=20 March 2014 }}</ref>

The ''Amphion'' class served the [[Royal Navy]] for almost three decades as the backbone of the [[Royal Naval Submarine Service]], and was gradually replaced with the [[British Porpoise-class submarine|''Porpoise'']] and {{sclass|Oberon|submarine|5}} patrol classes that began to be phased in during 1958.  The last operational ''Amphion''-class boat, {{HMS|Andrew|P423|2}}, was decommissioned in 1974.

==Boats==
[[File:HMS Alliance torpedo tube.jpg|thumb|A torpedo tube on HMS ''Alliance'']]
[[File:HMS Alliance in 2008.jpg|thumb|HMS ''Alliance'' in 2008]]

=== Built at Vickers-Armstrong, Barrow-in-Furness ===
* [[HMS Amphion (P439)|''Amphion'' (P439/S39/S43)]] (laid down as ''Anchorite'' but name changed before launch)
* [[HMS Astute (P447)|''Astute'' (P447/S47/S45)]]
* [[HMS Auriga (P419)|''Auriga'' (P419/S19/S69)]]
* [[HMS Aurochs (P426)|''Aurochs'' (P426/S26/S62)]]
* [[HMS Alcide (P415)|''Alcide'' (P415/S15/S65)]]
* [[HMS Alderney (P416)|''Alderney'' (P416/S16/S66)]]
* [[HMS Alliance (P417)|''Alliance'' (P417/S17/S67)]] (now at [[Royal Navy Submarine Museum]], [[Gosport]])
* [[HMS Ambush (P418)|''Ambush'' (P418/S18/S68)]]
* [[HMS Anchorite (P422)|''Anchorite'' (P422/S22/S64)]] (originally laid down as ''Amphion'' but name changed before launch)
* [[HMS Andrew (P423)|''Andrew'' (P423/S23/S63)]]

=== Built at Cammell Laird, Birkenhead ===
* [[HMS Affray (P421)|''Affray'' (P421)]] (the last British submarine lost at sea)
* [[HMS Aeneas (P427)|''Aeneas'' (P427/S27/S72/SSG72)]]
* [[HMS Alaric (P441)|''Alaric'' (P441/S41)]]

=== Built at Scotts Shipbuilding and Engineering Company of Greenock ===
* [[HMS Artemis (P449)|''Artemis'' (P449/S39/S49)]]
* [[HMS Artful (P456)|''Artful'' (P456/S56/S96)]]

=== Built at HM Dockyard, Chatham ===
* [[HMS Acheron (P411)|''Acheron'' (P411/S11/S61)]]

=== Built at HM Dockyard, Plymouth ===
These were the two vessels which were launched but not completed.
* [[HMS Ace (P414)|''Ace'' (P414)]]
* [[HMS Achates (P433)|''Achates'' (P433)]]

=== Cancelled orders ===
In 1945, besides the two vessels at Devonport, the following orders were cancelled:
{{column|num=3
|1=
'''Vickers-Armstrongs, Barrow-in-Furness''';
* HMS ''Andromache'' (P424)
* HMS ''Answer'' (P425)
* HMS ''Antagonist'' (P428)
* HMS ''Antaeus'' (P429)
* HMS ''Anzac'' (P431)
* HMS ''Aphrodite'' (P432)
* HMS ''Approach'' (P435)
* HMS ''Arcadian'' (P436)
* HMS ''Ardent'' (P437)
* HMS ''Argosy'' (P438)
* HMS ''Atlantis'' (P442)
|2=
'''[[Vickers-Armstrongs]], [[Walker, Newcastle upon Tyne|Walker-on-Tyne]]''';
* HMS ''Admirable'' (P434)
* HMS ''Asperity'' (P444)
* HMS ''Austere'' (P445)
* HMS ''Adversary'' (P457)
* HMS ''Awake'' (P459)
* HMS ''Aztec'' (P455)
'''Portsmouth Dockyard''';
* HMS ''Abelard'' (P451)
* HMS ''Acasta'' (P452)
|3=
'''Cammell Laird''';
* HMS ''Agate'' (P448)
* HMS ''Aggressor'' (P446)
* HMS ''Agile'' (P443)
* HMS ''Aladdin'' (P454)
* HMS ''Alcestis'' (P453)
'''Scotts of Greenock'''
* HMS ''Asgard'' (P458)
* HMS ''Assurance'' (P462)
* HMS ''Astarte'' (P461)
'''Chatham Dockyard'''
* HMS ''Adept'' (P412)
}}

==See also==
{{Portal|United Kingdom}}
*[[List of ship classes of the Second World War]]

==Notes and references==
{{reflist}}

== External links ==
*{{Commons category-inline|Amphion class submarines}}
*[https://www.maritimequest.com/warship_directory/great_britain/submarines/submarine_index.htm Maritimequest Amphion Class Index]
*[https://web.archive.org/web/20070928142711/http://www.submarinesonstamps.co.il/openhist.php?ID=69 Submarines On Stamps]

{{Amphion class submarine}}
{{WWII British ships}}
{{UK submarine classes after 1945}}

[[Category:Submarine classes]]
[[Category:Amphion-class submarines| ]]