HMS Onyx (J221): Steady Arctic Convoy Work on the Approach to D-Day

The Build: Harland and Wolff

HMS Onyx was ordered on 15 November 1940 from Harland and Wolff in Belfast, laid down on 24 November 1941, launched on 27 October 1942 and commissioned on 26 March 1943, a turbine-powered Algerine-class minesweeper displacing 850 tons standard, armed with a single 4-inch anti-aircraft gun and a substantial fit of Oerlikon and, later, Bofors anti-aircraft guns, alongside the depth charge equipment that gave her a genuine secondary anti-submarine capability.

Working Up Off Tobermory

HMS Onyx conducted anti-submarine exercises off Tobermory in September 1943 alongside the submarine HMS P511 and the sloop HMS Magpie, the demanding training regime through which so many escort vessels were put before being trusted with the real, life-or-death responsibility of convoy protection. She made the passage north from Harwich to Scapa Flow that November, and rounded off her work-up with further exercises off Scapa in December alongside HMS Vampire and HMS Swift.

Escorting the Arctic Convoys

HMS Onyx departed Loch Ewe on 22 January 1944 as part of the escort force for Convoy JW 56B, under the command of Temporary Acting Lieutenant Commander C. C. L. Gaussen, before being detached on 26 January and proceeding to Seidisfjord to refuel. It was, as it turned out, extremely good timing to be elsewhere: three days later a pack of German U-boats fell on the convoy she had just left, sinking the destroyer HMS Hardy (finished off by her own side once damage put salvage beyond hope) and prompting a running four-day battle of torpedo attacks and depth-charge counterattacks that Onyx's own detachment had spared her from entirely.

What happened to the ship she left behind is set out in the article on HMS Hardy (R08). It is worth sitting with the mechanism for a moment, because it is not luck in the way the word is usually meant. Onyx was not spared by anybody's judgement or by any decision taken on the night. She was detached to refuel because a fuelling schedule drawn up weeks earlier said that this was the day, and the difference between being in a four-day running battle and being alongside an oiler in a Faroese fjord came down to a line on a staff officer's timetable.

She joined a further Arctic convoy, JW 58, departing Loch Ewe on 27 March 1944, remaining with the convoy until 29 March, when she parted company and made her way to Skaalefjord in the Faroe Islands. This one travelled in altogether grander company: the battleships HMS Duke of York and HMS Anson and carrier HMS Victorious provided distant cover, while Captain Frederic "Johnnie" Walker's celebrated 2nd Escort Group, the most successful U-boat-hunting team of the entire war, sailed with it. By the time JW 58 reached the Kola Inlet on 4 April, three U-boats had been sunk for the loss of not a single merchant ship, a rare unambiguous convoy success, and Onyx's own safe delivery of the convoy to that point in the passage had been part of setting it up.

This kind of steady, rotating escort work, joining a convoy for one dangerous stretch of the journey before handing over to another escort group, formed the backbone of how the Arctic convoy system actually operated, a gruelling and largely unglamorous routine repeated by dozens of small escort vessels throughout the winter of 1943 and 1944.

The relay is worth setting out properly, because an Arctic convoy did not have an escort. It had three or four at once, at different distances, and understanding that explains almost everything about a career like this one.

Innermost was the close escort: corvettes, minesweepers and armed trawlers that stayed with the merchant ships from one end of the passage to the other, whose job was to be there when a torpedo arrived. Outside them was the ocean escort of fleet destroyers, joining and leaving on a fuelling cycle, because a destroyer running at convoy speed in Arctic weather burns oil at a rate that governs everything she does. Further out again sat a cruiser covering force, placed to deal with a German raider. And further out still, usually invisible to everyone in the convoy, was the Home Fleet's heavy covering force, battleships and a carrier, kept over the horizon against the possibility that the Tirpitz might come out.

Onyx belonged to the innermost ring, and that is the whole explanation for a record with no single dramatic action in it. The outer rings exist to fight battles. The inner ring exists so that there is no battle, and when it works properly the log entry reads: convoy arrived. It is a strange sort of achievement to have to explain, but it is the one the entire system was built to produce.

A Quiet, Reliable Career

HMS Onyx's surviving records do not detail any dramatic single action or confirmed U-boat engagement, a situation shared by a great many of the escort vessels that kept the convoy system running throughout the war; her value lay not in any one headline moment but in the accumulated weight of many such uneventful, successfully completed passages, each one a convoy that reached its destination safely because ships like HMS Onyx were there to see it through.

Channel Duties Through the Approach to D-Day

Her Arctic convoy days behind her, HMS Onyx spent the summer of 1944, the D-Day landings and their immediate aftermath included, on minesweeping duties in the English Channel, part of the huge, unglamorous effort needed to keep the invasion shipping lanes clear of mines both old and freshly laid. She was released from that Channel work in October 1944 and took passage to Harwich, by which point the Normandy campaign she had helped keep supplied by sea was already won.

Scrapped in 1967

After VJ Day, Onyx stayed on with her flotilla for mine clearance work off the east coast of England, before a refit at Devonport in September 1945 sent her south to Plymouth Command for similar duties in the South West Approaches and the Bristol Channel. In March 1947 she moved north again to join the 3rd Flotilla at Port Edgar on the Forth, before finally paying off into reserve that August, laid up first at Portsmouth and later with the Reserve Fleet at Plymouth.

She sat in reserve for the best part of two decades before appearing on the Disposal List in 1966. HMS Onyx was scrapped on 5 April 1967, sold to BISCO for breaking up by T.W. Ward and arriving in tow at Inverkeithing, more than two decades after the war's end, closing out the career of a minesweeper whose remarkably useful wartime service was built on patience and reliability rather than dramatic action, the quiet, essential kind of naval work that so rarely gets remembered but so consistently mattered.