HMS Selene (P254): Gunfire in the Gulf of Siam

Built at Birkenhead

HMS Selene was built by Cammell Laird at Birkenhead, laid down in April 1943, launched the following spring and commissioned at Holy Loch in July 1944, an Improved S-class submarine that made the long voyage east through Gibraltar, Malta, Aden and on to Trincomalee to join the war against Japan.

Gunfire Off Sumatra and Siam

Through the spring and summer of 1945, Selene fought a notably active campaign against small Japanese coastal shipping, damaging and sinking sailing vessels off Sumatra that March before shifting her attention to the Gulf of Siam that June and July, where she sank several Japanese coasters and further sailing craft by gunfire.

That is the whole shape of the Far East submarine war by 1945 and it is worth being plain about. An ocean-going submarine with six torpedo tubes spent her days surfacing beside wooden coastal craft and destroying them with a three-inch gun, because American submarines had already sunk everything larger and what remained was the small stuff creeping along the coast at night. HMS Thule sets out what that work did to the men who had to do it.

One source suggests she may also have towed the midget submarine XE5 towards Hong Kong that summer as part of a special cable cutting operation, an operation since confirmed in published accounts as Operation Foil, aimed at the undersea telegraph cable between Hong Kong and Singapore.

Operation Foil, and Why a Cable Was Worth It

That operation has a name and it is a good deal stranger than the summary suggests. Selene sailed from Subic Bay in the Philippines on 27 July 1945 with the midget submarine XE5 in tow, bound for Hong Kong, to cut the undersea telegraph cable running between Hong Kong and Singapore.

The reasoning behind that is the interesting part. A submarine telegraph cable is completely secure: it is a wire on the seabed, and nobody can listen to it. So long as the Japanese could pass their signals between Hong Kong and Singapore by cable, those signals were invisible to Allied intelligence. Cut the cable and they have to use wireless instead, and wireless can be intercepted, direction-found and, by 1945, very often read. The operation was not about denying communication. It was about forcing the enemy to communicate in a way that could be overheard.

It very nearly did not happen. The tow parted during the passage, which for a thirty-foot craft with a crew of four in the open sea is close to a death sentence, and Selene could not reconnect it. XE5 went on to Hong Kong under her own power.

What she then had to do was find a cable. That meant three and a half days working in deep mud on the bottom off Hong Kong, with a diver going out of the midget submarine to grope for a wire he could not see, in an enemy anchorage. She cut it. Nobody was sure she had succeeded until after the Japanese surrender, when it could finally be checked, which means the crew came home not knowing whether any of it had been worth doing.

She was not working alone either. A companion operation, Sabre, sent the midget submarine XE4 after the cables running out of Saigon at almost the same time, towed out by another British submarine. The intention was to take the whole of Japanese-held South East Asia off cable together, so that everything the enemy said had to go by wireless at once, and all of it into Allied receivers.

It is the same class of operation HMS Stygian ran against the cruiser Takao at Singapore the same month, and the same class of submarine did the towing. Two British boats spent July 1945 dragging midget submarines across the South China Sea.

Correcting a Common Mix-Up

It is worth addressing directly a belief sometimes attached to this submarine, that she was eventually sold to the Danish Navy. No source consulted supports any such transfer, and Denmark's own postwar submarine fleet consisted of older U-class boats leased from Britain rather than any S-class vessel.

The likely source of the confusion is a similarly named but entirely unrelated Danish submarine, HDMS Sælen, whose name simply happens to sound close to Selene's own.

HMS Selene, in fact, remained in Royal Navy service throughout her career.

There is a better explanation for that mix-up than a similar-sounding name, and it is worth giving because it makes the mistake understandable rather than merely wrong. Denmark really did operate British submarines. From 1946 she leased three of them, and their names were Springeren, Storen and Saelen.

So somebody has remembered something true, that Britain lent Denmark submarines and one of them had a name resembling this one, and attached it to the wrong boat. The three that went were older U-class vessels, not S-class, and Selene was never among them. HMS Sentinel runs into exactly the same myth from the other direction and names all three.

The Saelen most people picture is different again, and later. She is a museum boat in Copenhagen today, she was built in Norway in 1965, and Denmark bought her in 1990. She has nothing whatever to do with the Second World War or with any British submarine.

A Long Peacetime Service

Selene returned to Portsmouth in November 1945 following Japan's surrender, and went on to serve for well over a decade afterwards, based at various points with flotillas at Portland and Rothesay and reportedly converted at some stage into an unarmed training target vessel to support the Navy's anti submarine forces.

She was finally scrapped at Gateshead in June 1961, closing out a career considerably longer and quieter than her active, gunfire filled final months against Japan might have suggested.

The conversion to an unarmed target is worth taking seriously rather than reading as a demotion. After 1945 the Royal Navy knew its next opponent would be Soviet submarines built on German designs, which meant fast and permanently submerged, and every escort crew in the fleet had been trained against an enemy that spent most of its time on the surface. All of that had to be relearned, and it could only be relearned against a real submarine.

So Selene was stripped of her armament, given the speed to be difficult, and spent the 1950s being hunted on purpose off Portland and Rothesay. HMS Untiring finished the same way and is still on the bottom off Devon where they left her.

Seventeen years, of which about eight months were spent at war. She fired her gun at wooden boats in the Gulf of Siam, dragged a midget submarine towards Hong Kong and lost it on the way, and then spent a decade and a half teaching the Royal Navy how to find submarines. Only one of those three is likely to be remembered, and it is arguably the least important.