HMS Diamond (D35): The Yard's First All-Welded Destroyer, Twice in Collisions

A First for Welded Construction

HMS Diamond was built by John Brown and Company at Clydebank, launched on 14 June 1950, and holds a properly notable technical distinction: she was John Brown's first all-welded ship, built without the traditional riveted construction that had defined shipbuilding for generations, a modernisation in build technique that reflected the broader postwar shift in how Britain's shipyards approached warship construction.

The name she was given had been vacant for nine years and the reason is worth knowing. The previous HMS Diamond was a D-class destroyer, and she was lost off Greece on 27 April 1941 in one of the grimmer episodes of that campaign. The troopship Slamat had been sunk while evacuating soldiers from the Greek beaches; Diamond and the destroyer Wryneck went in and took her survivors aboard, and both destroyers were then caught in the open by German aircraft and sunk with almost everyone they had just rescued. Something like a thousand men died between the three ships and about fifty survived. That story is told in the article on HMS Diamond (H22). It is worth holding in mind against what follows, because the ship that inherited the name went on to have a career whose worst days involved hitting other British warships in the dark.

It is worth understanding what that milestone actually meant on the slipway. A riveted ship is assembled by punching holes through overlapping steel plates and hammering red-hot rivets through them, which needs a squad of four to each rivet, produces a hull with a seam every few feet, and leaves you with something that leaks, weighs more than it needs to and takes a very long time to build. A welded ship is fused into a single continuous structure. It is lighter, stronger, quicker and quieter. The Royal Navy had been cautious about it because early all-welded hulls had a nasty habit of cracking in cold water, as a number of American-built Liberty ships had demonstrated by breaking clean in half, and it took the best part of a decade of metallurgy to work out why. By 1950 the answer was known, and John Brown of Clydebank, a yard that had riveted the Queen Mary and HMS Hood, built its first ship without a single rivet in her. Her name was Diamond. What the Daring class was is set out in the article on HMS Dainty.

One more thing about the welding is worth adding, because it did not stop with her. Once the metallurgy was understood, welded construction changed not just how ships were built but who could build them. Riveting is a craft skill learned over years by squads working together; welding can be taught faster, done by fewer people, done by women, done under cover, and above all done on prefabricated sections built away from the slipway and then lifted into place. Every large warship built in Britain since has been assembled that way, and the modern practice of building a frigate as a set of blocks in a covered hall and joining them up is the direct descendant of what John Brown did with Diamond in 1950. The yard that riveted the Queen Mary and the Hood taught itself a new trade on a destroyer, and the destroyer stayed afloat for thirty-one years.

A Collision at Exercise Mariner

HMS Diamond took part in the June 1953 Fleet Review celebrating the coronation of Queen Elizabeth II, but suffered a serious setback that September: on 29 September 1953, she sustained severe bow damage after colliding with the cruiser HMS Swiftsure during Exercise Mariner off Iceland, a major NATO naval exercise, a remarkably significant accident for so young a ship barely three years into her active career.

Exercise Mariner deserves more than a passing mention, because the conditions explain the accident. It ran for nineteen days in the late summer of 1953 and was, at that point, about the largest international naval exercise ever attempted: nine nations, nearly fifty different types of ship and twenty of aircraft, working convoy protection and fleet operations across the northern Atlantic, with the battleship HMS Vanguard and the carrier HMS Eagle among them. It then ran into force nine winds and stayed in them. Ships were damaged by the sea alone. And, because it was an exercise in wartime conditions, the fleet was darkened: no navigation lights, minimal radio. Two ships manoeuvring in a gale, at night, without lights, is a situation that has only ever had one outcome, and on 29 September it had it.

Diamond came off much the better. Her bow was crushed and she was photographed at Sheerness a week later looking very sorry for herself, but she was repaired and went on to serve another twenty-eight years. The cruiser did not. HMS Swiftsure was patched up and then sat, inactive, for over three years; when she finally went into Chatham in February 1957 for a proper refit, the dockyard opened her up and found the collision damage was a great deal worse than anybody had realised. She never went to sea again. The ship the Royal Navy had chosen to take the surrender of Hong Kong in 1945 was finished off, in the end, by a three-year-old destroyer in the dark off Iceland.

Suez and a Second Collision

HMS Diamond deployed to Port Said in 1956 for flag-showing operations ahead of the Franco-British intervention in the Suez Crisis, subsequently joining the main assault force for Operation Musketeer at Port Said itself, direct participation in one of the defining and most controversial episodes of postwar British foreign policy.

Her Suez role is more pointed than flag-showing suggests. She was sent into Port Said before the assault precisely as a piece of pressure, a modern destroyer sitting in an Egyptian harbour to make a diplomatic argument by being visible; the Egyptian government was entirely unmoved, and she sailed out and joined the attack force instead. When the landings went in on 5 and 6 November 1956 she was one of the ships bombarding the beaches to soften them for the troops going ashore. There is a certain awkwardness in that, and it is worth stating plainly rather than glossing: Port Said was a city of some quarter of a million people, the bombardment was deliberately limited in calibre for exactly that reason, and the casualty figures are still argued about. The operation was halted within two days by American financial pressure and a United Nations vote. It remains the clearest example in modern British history of a military operation that worked and a policy that did not.

She underwent a refit at Chatham Dockyard in 1959, but her run of accidental mishaps continued in 1964, when she collided with the frigate HMS Salisbury in the English Channel during a naval demonstration, a second embarrassing collision to add to her service record.

The second collision has a date and a cause, and both are instructive. On 23 June 1964 Diamond and the frigate HMS Salisbury ran into each other in the English Channel during a naval demonstration, having been steaming too close together. That is a phrase worth unpacking, because a naval demonstration means ships manoeuvring in company for an audience, which in turn means close formation, tight turns and a premium on looking impressive. Ships in company are held at intervals measured in hundreds of yards at twenty-odd knots, and the margin for a misread signal or a late helm order is a matter of seconds. It happened to Diamond twice in eleven years, once in a force nine gale off Iceland with no lights showing and once in a flat calm in the Channel in front of spectators, which between them cover the two ways a warship collides with another warship: too little information, or too much confidence.

A Long Retirement as a Training Ship

From 1970 onwards, HMS Diamond was converted into a Harbour Training Ship, moored at the Priddy's Hard jetty in Gosport and attached to HMS Sultan's Marine Engineering School, with her operational steam plant deliberately maintained specifically to give trainee engineers hands-on experience with real, working machinery rather than simulators alone, a truly valuable final role for a ship whose active seagoing career, however eventful, had by then run its course.

The detail about the steam plant is the interesting one. HMS Sultan at Gosport is the Royal Navy's marine engineering school, and the reason it wanted a real destroyer moored at Priddy's Hard rather than a set of training rigs is that a working steam plant misbehaves in ways no rig reproduces: it leaks, it vibrates, things seize, and a young artificer has to find out why with the thing running. Priddy's Hard itself had been the Navy's great powder magazine at Portsmouth since the 1770s and is a museum today. HMS Crossbow did the same job at Sultan a few years earlier, as set out in her own article. It is not a glamorous end. It is arguably the most useful thing a worn-out warship can be.

The End of Service

HMS Diamond was eventually replaced in her training role by HMS Londonderry and was scrapped at Rainham, Kent, in 1981, closing out more than three decades of service that had begun with a genuine construction milestone and included both a major Cold War international crisis and two separate collisions with fellow Royal Navy warships along the way.