HMS Defiance (A187): The Submarine Depot Ship That Sailed From Holy Loch to Singapore

Laid Down at Clydebank

HMS Defiance began life as HMS Forth, built by John Brown and Company at Clydebank, launched on 11 August 1938 and commissioned on 14 May 1939, a Maidstone-class submarine depot ship carrying eight 4.5-inch dual-purpose guns and eight 2-pounder anti-aircraft guns, built specifically to provide maintenance, supplies and accommodation for entire flotillas of submarines rather than to fight independently herself.

At 497 feet long and displacing almost 8,900 tons, she carried a complement of 1,167 officers and men, a floating small town's worth of engineers, torpedomen and stores staff assembled purely to keep somebody else's submarines fighting fit.

The armament is the detail that stops people short, and it is not decoration. Eight 4.5-inch guns in four twin high-angle mountings, backed by eight 2-pounders, is a heavier anti-aircraft battery than a good many cruisers of the period carried, fitted to a ship whose entire function was maintenance. The reason is geography. A depot ship works at anchor, in daylight, in a fjord or a creek or an open roadstead, with several submarines secured alongside her in trots and most of their crews aboard eating, sleeping or having their teeth seen to. She cannot manoeuvre, she cannot hide, and if she is hit the whole flotilla is hit with her. She is, in other words, the single most attractive target in any anchorage she happens to be in, and the Admiralty armed her accordingly.

The phrase floating small town is closer to literal than it sounds, and the inventory is worth reading. A Maidstone-class depot ship carried a foundry. She carried coppersmiths', plumbers' and carpenters' shops, heavy and light machine shops, electrical and torpedo repair shops, and the plant to charge submarine batteries. She held more than a hundred torpedoes and about as many mines, and she carried enough diving and salvage gear to go and get things off the bottom. She was designed to keep nine operational submarines running, indefinitely, anywhere there was water deep enough to anchor in.

And because a submarine has nowhere to put people, she carried the rest of it too: steam laundries, a bakery, two canteens, a barber's shop, a cinema, a chapel, and a hospital with a fully equipped operating theatre and a dental surgery. A submarine crew coming in from a fortnight in the North Sea went aboard the depot ship to sleep in a proper bunk, eat food somebody else had cooked, have their teeth seen to and watch a film. That is what a depot ship was for, and it is why the Royal Navy could run submarine flotillas from Malta, Halifax, Holy Loch and Singapore without building a single dockyard.

Wartime Service in Home Waters

HMS Forth spent most of the Second World War based in home waters, apart from a brief period at Halifax, Canada, in 1941. She moved to Holy Loch on the Firth of Clyde in 1940, and that February sailed from Greenock for Halifax alongside the Polish-crewed troop transport Batory, escorted by the destroyers HMS Hesperus and HMS Hurricane, the submarines operating out of Halifax at the time providing a useful extra layer of protection for convoys against surface raiders.

That Halifax passage needs its reason spelled out, because British submarines in Nova Scotia sounds like somebody misreading a chart. February 1941 is precisely the moment the German surface raiders were loose in the North Atlantic. Scharnhorst and Gneisenau were out together on Operation Berlin and took twenty-two Allied merchant ships between January and March; the heavy cruiser Admiral Hipper was working the same water. Against a battleship, a convoy escort of corvettes and elderly destroyers can do essentially nothing except make smoke and be brave.

A submarine is different. She is the one thing a fast, heavily armed surface raider genuinely has to worry about, because a raider cannot see her coming, cannot outrun a torpedo already in the water, and cannot afford even minor damage two thousand miles from a dockyard. So Forth took a handful of boats across and based them at the western end of the convoy routes, on the reasoning that a raider who knew submarines were waiting at the assembly ports might decide to be somewhere else, and that if one did come in, there would at last be something present that could hurt it. It is a very small operation and it never made a headline, but it is a neat illustration of what a depot ship is actually for: she is the reason submarines can be based anywhere at all, including places that have never seen one.

Holy Loch deserves a paragraph of its own. It is a short sea loch off the Firth of Clyde, deep, sheltered and close enough to the open Atlantic to be useful, and from 1940 it was where Britain kept its submarines. Forth sat at anchor in the middle of it with the boats of the 3rd Submarine Flotilla secured alongside her in trots, and that flotilla had two jobs: it ran the submarines working the North Sea and the Bay of Biscay, and it supervised the trials and working up of every newly built British submarine. Every boat that went to war went through Holy Loch first, and Forth is the ship they came alongside.

There is a long coda to that. Forth left in 1945 for Rothesay, and sixteen years later Holy Loch filled up again, this time with Americans: from 1961 to 1992 it was the United States Navy's forward base for Polaris and then Poseidon ballistic missile submarines, with a depot ship of their own moored more or less where Forth had lain, and a submarine tied up alongside her doing the same thing for the same reasons. The technology changed out of all recognition. The idea, a big ship full of workshops sitting in a Scottish loch keeping other people's submarines at sea, did not change at all.

During 1943, she served as a target vessel for submarine attack exercises in the Clyde area, valuable if unglamorous training work supporting the development of the submarine crews she would otherwise have been supporting in a more conventional depot ship role.

She was adopted by the county of Stirlingshire during that year's Warship Week fundraising campaign, with the adoption plaque today held by the National Museum of the Royal Navy.

Malta, Nuclear Submarines and Singapore

HMS Forth was stationed in Malta during the 1950s, moored at Msida creek, and took part in the June 1953 Fleet Review celebrating the coronation of Queen Elizabeth II. Between 1962 and 1966, she was modified at Chatham Dockyard specifically to support the Royal Navy's new nuclear-powered submarines, a particularly significant adaptation given how recently nuclear propulsion had entered British naval service, with HMS Dreadnought, the fleet's first nuclear-powered submarine, having only commissioned in 1963 and the Valiant class still under construction.

The nuclear modification is worth a note too, because it was not a matter of stocking different spare parts. Supporting a nuclear submarine means being able to handle primary circuit water chemistry, to monitor and control radiological work, to store and account for contaminated material, and to give the crew somewhere to be while all of it happens. Forth went into Chatham in 1962 as a ship built to look after diesel boats with torpedoes in them and came out four years later able to look after reactors, which for a hull laid down before the Second World War is a considerable second education.

In mid-1966, HMS Forth arrived in Singapore to relieve HMS Medway as depot ship for the 7th Submarine Squadron, and in 1968 she transported the first hovercraft to reach Australia, an unusual cargo for a vessel more usually associated with submarine maintenance.

Becoming HMS Defiance

HMS Forth departed Singapore on 31 March 1971 and reached the United Kingdom on 7 June that year, before being renamed HMS Defiance on 15 February 1972.

That name carried real history. The original HMS Defiance was the last wooden battleship the Royal Navy ever launched, built in 1861 and turned two decades later into a floating torpedo school moored in the Hamoaze off Wearde Quay, near Saltash. As the school grew, successive retired hulks joined her and took on the same name in turn, Defiance II, III and IV among them, until the whole establishment finally moved ashore to Portsmouth in 1955. Seventeen years on, the name returned to the water with a rather more modern job to do.

She went on to serve until 1978 as depot ship for the Fleet Maintenance Base at HM Naval Base Devonport, decommissioning on 1 January 1979 after a role that had kept her useful well into her fourth decade of service.

The name did not stop when the ship did, either. On 12 March 1981, two years after she paid off, the Fleet Maintenance Base at Devonport was itself commissioned as HMS Defiance, and it carried on as a shore establishment until 1994, when it was folded into HMS Drake. Trace the name back and the thread through all of it is the same one: a wooden battleship turned torpedo school, a line of hulks moored off Saltash, a floating base that had to shift from Wearde Quay up to Wilcove because the newer hulks drew too much water for the old berth, a purpose-built depot ship, and finally a shore establishment. Every one of them existed to put somebody else's ship right. Not many names in the Royal Navy have held a single idea that steadily for a hundred and thirty years.

The End of Service

HMS Defiance was eventually scrapped on 25 July 1985, closing out a career of nearly half a century that had carried her from wartime depot duty on the Clyde through nuclear submarine support work and a Far Eastern posting in Singapore, to a final chapter supporting Devonport's submarine maintenance base under a name with a long tradition of its own within the Royal Navy.