HMS Onyx (S21)

{{main|Oberon-class submarine}}

The Oberon class was a direct follow on of the Porpoise class, with the same dimensions and external design, but updates to equipment and internal fittings, and a higher grade of steel used for fabrication of the pressure hull.{{cite book |last=Chant |first=Christopher |title=Submarine Warfare Today: The World's Deadliest Underwater Weapons Systems |publisher=Silverdale Books |location=Wigston |date=2005 |isbn=1-84509-158-2|oclc=156749009 |page={{page needed|date=June 2015}}}}

As designed for British service, the Oberon-class submarines were {{convert|241|ft}} in length between perpendiculars and {{convert|295.2|ft}} in length overall, with a beam of {{convert|26.5|ft}}, and a draught of {{convert|18|ft}}.{{cite book |editor=Moore, John |title=Jane's Fighting Ships 1977-78 |edition=80th |year=1977 |series=Jane's Fighting Ships |publisher=Jane's Yearbooks |location=London |isbn=0531032779 |oclc=18207174 |page=490}} Displacement was 1,610 tons standard, 2,030 tons full load when surfaced, and 2,410 tons full load when submerged. Propulsion machinery consisted of two Admiralty Standard Range 16 VMS diesel generators, and two {{convert|3,000|shp|adj=on}} electric motors, each driving a {{convert|7|ft||adj=mid|diameter}} three-bladed propeller at up to 400 rpm. Top speed was {{convert|17|kn}} when submerged, and {{convert|12|kn}} on the surface. Eight {{convert|21|in|adj=on}} diameter torpedo tubes were fitted (six facing forward, two aft), with a total payload of 24 torpedoes. The boats were fitted with Type 186 and Type 187 sonars, and an I-band surface search radar. The standard complement was 68: 6 officers, 62 sailors.

Onyx was laid down by Cammell Laird on 16 November 1964, and launched on 18 August 1966. During Onyx{{'}}s construction there was an explosion which took the life of a shipyard worker and severely wounded communist union leader Barry Williams. The boat was commissioned into the Royal Navy on 20 November 1967. Onyx was ordered after a previous Oberon-class submarine of the same name (laid down by Chatham Dockyard in 1962) was transferred to the Royal Canadian Navy as {{HMCS|Ojibwa|S72|6}} before launching in February 1964.

{{expand section|date=June 2015}}

The first commission of Onyx saw her visit Swansea in South Wales for the investiture of His Royal Highness The Prince of Wales. She also attended the bicentennial celebrations of the United States of America in 1976.

Onyx was the only non-nuclear submarine of the Royal Navy to take part in the Falklands War.The diesel submarine went south with a special 5 man diving chamber and fully armed with 10 MK 24, 2 Mk 20 and 11 Mk 8 torpedoes P. Hennessy & J. Jinks. The Silent Deep.The RN Submarine Service since 1945. Allen Lane (2015) London, p 444

Onyx was tasked with providing reconnaissance photographs of enemy installations enforcing the exclusion zone around the Falklands.{{Cite web |title=THE FALKLANDS CONFLICT, APRIL - JUNE 1982 |url=https://www.iwm.org.uk/collections/item/object/205018850 |access-date=2023-12-12 |website=Imperial War Museums}} Her smaller displacement compared to the nuclear submarines also made her ideal for landing SBS and SAS special forces, picked up from Ascension Island, ashore on the islands in shallow waters.Bonds, Ray and Miller, David (2003). illustrated Directory of Special Forces. Zenith Imprint, p. 109. {{ISBN|0-7603-1419-5}} The charts used for these landings, however, were made 200 years before the war.{{Cite web |title=Dean Rogers from the RNRMC recalls the end of the Falklands conflict {{!}} The Royal Navy and Royal Marines Charity |url=https://www.rnrmc.org.uk/news/dean-rogers-rnrmc-recalls-end-falklands-conflict |access-date=2023-12-12 |website=www.rnrmc.org.uk}}

During one of these missions, Onyx hit an uncharted pinnacle while submerged at {{convert|150|ft}} and suffered minor damage to her bow.Ewen Southby-Tailyour, Exocet FalklandsShips Monthly, Volume 28. Waterway Productions Ltd., 1993 Another claim is that the damage was inflicted by one of two torpedoes dropped by an Argentine Navy S-2E Tracker aircraftJ C Cicalesi & S Rivas, 'Argentine Strike Frustrated' in Warship International Fleet Review, August 2007, p 40 from {{ship|ARA|Veinticinco de Mayo|V-2|6}} operating {{convert|70|nmi}} off the Argentine coast. The Tracker S-2 twice detected sub-surface and electronic traces and a magnetic anomaly detector contact on 5–6 May while searching for {{ship|ARA|Alférez Sobral}} which was out of contact after being hit by Sea Skua missiles launched by Westland Lynx helicopters.

Contrary to some reports,{{cite news|url=https://www.telegraph.co.uk/news/worldnews/southamerica/argentina/1387091/SAS-suicide-mission-to-wipe-out-Exocets.html|title=SAS 'suicide mission' to wipe out Exocets|publisher=The Telegraph|date=2002-03-08|access-date=2011-12-16}} after the British cancelled Operation Mikado, there was never a plan to use Onyx to land the SAS in order to destroy Argentina's remaining stockpile of Exocet missiles. Prior to the submarine being damaged the SBS had been embarked to attack a mainland airfield but this operation, too, was cancelled.

Postwar, Onyx sank the hulk of the landing ship {{RFAux|Sir Galahad|1966|6}} with a Mk 8 Torpedo after firing two Mk 24 Tigerfish, the second Tigerfish, after a ten-minute delay, at the hulk; both failed to explodeP. Hennessy & J Jinks. The Silent Deep. The RN Submarine Service since 1945. Allen Lane (2015) London, pp. 443–444, 451–452 probably due to torpedo battery faults. Sir Galahad had been damaged beyond repair during an Argentine Air Force raid at Fitzroy and Bluff Cove.

File:Historic warships Birkenhead - geograph.org.uk - 60479.jpg

Defence cuts in the UK saw the Royal Navy dispense with its diesel-powered submarines to concentrate on nuclear attack submarines. In 1991, Onyx was decommissioned from the navy. She was then cared for by the Warship Preservation Trust and was on public display alongside several other ships in Birkenhead, UK.

In May 2006, Onyx was sold to the Barrow-in-Furness businessman Joe Mullen, for a reported £100,000 as a 'gift to the people of Barrow'. She left Birkenhead on 13 June 2006{{citation|url=http://www.photoboxgallery.com/MaritimeAviationNews/collection?album_id=94092267& |title=Photo: HMS Onyx leaves Birkenhead|access-date=12 August 2007}} to form the centrepiece of The Submarine Heritage Centre, a new heritage museum in Barrow-in-Furness, Cumbria, as a celebration to the town's illustrious submarine-building history.

After the submarine museum went into debt she was taken by an unknown liquidation company as a financial asset, to be broken up for scrap. A small party from HMS Exploit gave her a send off recognising her contribution to the Navy and country in the Cold War and Falklands conflict. On 30 April 2014 she was sailed from Barrow in tow for the Clyde and berthed at Rosneath amid continued uncertainty as to whether at least part of Onyx might be preserved.{{cite news|title=Remains of submarine in Barrow dock set to be scrapped|url=http://www.nwemail.co.uk/news/remains-of-submarine-in-barrow-dock-set-to-be-scrapped-1.1131486|access-date=2 May 2014|newspaper=North West Evening Mail|date=23 April 2014|location=Barrow-in-Furness|url-status=dead|archive-url=https://web.archive.org/web/20140502055928/http://www.nwemail.co.uk/news/remains-of-submarine-in-barrow-dock-set-to-be-scrapped-1.1131486|archive-date=2 May 2014|df=dmy-all}}{{cite news|title=Falklands veteran sub leaves Barrow and embarks on her final voyage|url=http://www.nwemail.co.uk/news/falklands-veteran-sub-leaves-barrow-and-embarks-on-her-final-voyage-1.1133207|access-date=2 May 2014|newspaper=North West Evening Mail|date=1 May 2014|location=Barrow-in-Furness|url-status=dead|archive-url=https://web.archive.org/web/20140502054803/http://www.nwemail.co.uk/news/falklands-veteran-sub-leaves-barrow-and-embarks-on-her-final-voyage-1.1133207|archive-date=2 May 2014|df=dmy-all}} Onyx was alongside Rosneath Jetty on the Gare Loch, Scotland on 18 July 2014. She was scrapped in Rosneath later that year.{{Cite web|url=http://www.drbmarine.co.uk/hms-onyx.html|title = RB Marine Services Limited}}

• British Naval Forces in the Falklands War

{{Reflist|30em}}

• [http://www.submarineheritage.com/ The Submarine Heritage Centre]

{{Oberon class submarine}}

{{Falklands War British ships}}

{{National Historic Ships}}

{{1982 shipwrecks}}

{{DEFAULTSORT:Onyx (S21)}}

Category:Oberon-class submarines of the Royal Navy

Category:Ships built on the River Mersey

Category:1966 ships

Category:Cold War submarines of the United Kingdom

Category:Falklands War naval ships of the United Kingdom

Category:Maritime incidents in 1982