HMS Thule (P325): Twenty Vessels in Twelve Days

The Build: Devonport

HMS Thule was built at Devonport Dockyard and launched on 22 October 1942, a third-group T-class submarine that went on to serve extensively in the Far East against Japan.

The name is the first oddity about her. Thule was the far north of the ancient world, the place beyond the known map where Pytheas reported ice and midnight sun, and it has come down to us in the phrase ultima Thule, meaning the last place there is. It was hung on a submarine that spent almost her entire war within a few degrees of the equator, in some of the hottest and most humid water any British boat operated in. Sixty men in a steel tube off Sumatra in December would have appreciated the joke.

She belonged to the third group of the T class, the last and best of them, built with all-welded pressure hulls rather than riveted ones. That mattered enormously a few years later, when eight of those welded boats were cut in half at Chatham and rebuilt into fast underwater submarines for the Cold War, a programme set out in HMS Truncheon. Thule was not among the eight. She was, however, given the other great postwar addition, a snort mast, which is how she came to have one for a Portland tanker to damage in 1960.

A Remarkable Twelve Days

Between 17 and 29 December 1944, Thule embarked on an extraordinarily productive run through the Strait of Malacca, sinking thirteen junks, two lighters and five sampans by gunfire, a striking twenty vessels destroyed in less than a fortnight.

That figure needs unpacking rather than admiring, because a junk is not a freighter. What Thule was sinking were small wooden coastal craft: sailing junks of a few tens of tons, often with an auxiliary engine, unpowered lighters, and sampans, which are smaller again. They were destroyed by gunfire, from the surface, at ranges where the men firing could see the men being fired at. This was not a torpedo attack from periscope depth against a shape on the horizon.

The reason British submarines were doing this by the end of 1944 is that there was very little else left. The large Japanese merchant ships in the Indian Ocean and the Malacca Strait had already been sunk, largely by American submarines further east and by boats like HMS Tally-Ho closer to hand, and what remained of Japanese logistics in the region had moved into small craft hugging the coast in shallow water. A submarine cannot torpedo a junk drawing four feet. She has to surface and use the gun.

The vessels themselves occupied an uncomfortable position. Many were Chinese-owned trading junks that the Japanese had commandeered, some were armed and operating as patrol craft, and the crews were frequently local men rather than Japanese servicemen. The submariners doing the work knew all of this. The accounts that survive are not triumphant: one described these close-range surface actions as intolerably personal, and a number of commanding officers were reluctant to fight them at all and occasionally declined. It remained an argument, both moral and tactical, for the whole of the campaign.

The tactical case for it was real and it worked. Japanese forces in Burma were being supplied down that coast, and by March 1945 British submarines had closed the Strait of Malacca so completely that nothing was reaching them by sea at all. An army that cannot be resupplied stops being an army, and the Fourteenth Army fighting its way back through Burma benefited directly from work of exactly this kind. Twenty vessels in twelve days is a real contribution to that. It is also thirteen junks, and both things are true at once.

She also engaged a Japanese submarine, most likely the Ro-113, though a premature torpedo detonation allowed the enemy boat to escape, and went on to destroy five further sailing vessels and three coasters, alongside deploying mines during her patrols.

That failure has a long history behind it. Premature detonation had dogged British torpedoes since the beginning of the war, usually from magnetic influence pistols firing on the target's magnetic field rather than on contact, and every submarine navy in the war suffered some version of it. A torpedo that explodes short does worse than miss. It announces the attack, tells the target roughly where the attacker is, and gives him time to go deep or run. Submarine against submarine is the hardest shot in the business, HMS Trespasser having demonstrated on a dead whale how difficult identification alone could be, and Thule got the one chance and lost it to her own weapon.

The Man Who Commanded Her

Her commanding officer through the Far East patrols was Lieutenant Commander Alastair Campbell Gillespie Mars, DSO, DSC and Bar, and his career is one of the strangest the Submarine Service has produced.

Before Thule he had HMS Unbroken in the Mediterranean, and on 13 August 1942, at the age of twenty-seven, he fired a salvo off the north coast of Sicily that hit two Italian cruisers. The heavy cruiser Bolzano and the light cruiser Muzio Attendolo were both badly damaged, neither of them fought again in any meaningful way, and it happened during Operation Pedestal, the convoy operation that kept Malta in the war. Putting two cruisers out of the war with one salvo is about as much as a submarine can hope for in an afternoon, and he was given a DSO for it.

Then Thule, the Malacca Strait, and the twelve days in December 1944. He wrote a book about that commission afterwards, HMS Thule Intercepts, which is a large part of why this submarine's war is documented at all when so many contemporaries left nothing behind but a patrol report.

What happened next is harder to read. Mars spent four years after the war trying to obtain an allowance he could actually live on, with a seriously ill wife to care for, and got nowhere. In June 1952 he was court martialled for insubordination and absence without leave, and dismissed from Her Majesty's service. A man with a DSO and a DSC and Bar, who had crippled two Italian cruisers in a single attack and taken a submarine through the hardest water in the Far East, was put out of the Navy over money for his wife's care. He wrote about that too, in a book called Court Martial, and he spent the rest of his life writing. He died in 1985.

None of that is Thule's doing and it does not belong to her record. It is worth having here all the same, because the twenty vessels in twelve days were not achieved by a submarine. They were achieved by a ship's company under a particular man, and what became of him afterwards is part of what the country did with the people it had used.

A Postwar Posting to Canada

Thule survived the war and, in May 1951, deployed to Canada to take part in training exercises with the Royal Canadian Navy, a quieter but still valuable contribution to Allied submarine training in the early Cold War years.

An Accidental Collision

On 18 November 1960, while conducting anti-submarine drills off Portland Bill at periscope depth, Thule was accidentally rammed by the Royal Fleet Auxiliary tanker Black Ranger, an incident that damaged her snort system and periscope. She survived this final scrape and was scrapped by Thos. W. Ward at Inverkeithing on 14 September 1962, bringing to a close the career of a boat whose most dramatic moments had come in a single frenetic fortnight off Malaya.

The Black Ranger business is a good illustration of the ordinary hazard of peacetime. She was a small fleet tanker, one of the Ranger class that spent decades refuelling warships at sea, and on 18 November 1960 she was acting as a target in an anti-submarine exercise off Portland Bill. Thule was at periscope depth beneath her doing what the exercise required. The two things a submarine has above water at periscope depth are a periscope and, if she is snorting, a snort mast, and those are exactly the two things that were damaged, which tells you the tanker went straight over the top of her. A few feet lower and it is a different story entirely.

She was broken up at Inverkeithing in September 1962, twenty years after she was launched. Her sisters had scattered: HMS Thorough had become the first submarine to circumnavigate the world, HMS Stygian had towed a midget submarine to war, and eight of the class had been rebuilt into something quite different. Thule had done none of those things. She had spent a fortnight in December 1944 doing difficult, close, unglamorous work in the Malacca Strait under a man the Royal Navy would later throw away, and it is the best and most complicated thing on her record.