HMS Trespasser (P312): The Great Whale Scare

Barrow-Built

HMS Trespasser was built by Vickers-Armstrongs at Barrow-in-Furness and launched on 29 May 1942, a third-group T-class submarine that served across home waters, the Mediterranean and the Far East, and remains, to this day, the only Royal Navy ship ever to carry the name.

She was launched without a name at all. In June 1940, with a very large submarine programme in prospect and a war to get on with, the Admiralty decided that naming boats individually was more trouble than it was worth and began issuing numbers instead: P31, P32, and so on through the series. Trespasser went down the ways at Barrow on 29 May 1942 as P312 and nothing else. At the end of that year Churchill intervened personally and ordered that submarines be named again, on the straightforward ground that men who might die in one were owed better than a number. HMS Tiptoe was one of the boats he named himself.

Trespasser is an odd choice even by the standards of a list that had to find a great many words beginning with T, and no Royal Navy ship has carried it before or since. It is also, in its way, an accurate description of the job: a submarine is a vessel whose entire purpose is to be somewhere she has no business being, without permission and without being noticed.

One boat from her own group never got a name. P311 was to have been Tutankhamen. She sailed from Malta on 28 December 1942 carrying chariots, the two-man human torpedoes, for an attack on the Italian anchorage at La Maddalena, and never arrived at the rendezvous. Her chariots were never launched. She had almost certainly run onto a mine off Tavolara in the first days of January 1943, and all seventy-one men aboard were lost. She is the only boat of the whole T class never to be given a name, and she went down within days of the order that would have given her one. A diver found her in 2016, sitting in eighty metres off Sardinia with the chariot containers still on her casing.

A Case of Mistaken Identity

Among the more memorable moments of her war, Trespasser once mistook a deceased whale for an enemy submarine in the Gulf of Lion and fired three torpedoes at the unfortunate creature, an entertaining misfire that stands as a reminder of just how difficult and imprecise underwater detection could be, even for an experienced crew doing their level best.

It is a better story once you know why it was a reasonable mistake. A dead whale floating awash is a long dark object lying low in the water with a rounded back and no obvious ends, seen through a periscope at a mile or two in a swell, and it looks very like the casing of a submarine on the surface. On ASDIC it is worse. A whale is a large mass of flesh and bone and air-filled lung in a body roughly the size of the thing being looked for, and it returns an echo of about the right strength from about the right sort of shape. Escort groups all over the Atlantic depth-charged whales throughout the war, and some of them did it more than once.

Three torpedoes was not a trivial thing to spend either. A T class boat sailed with what she carried and there was no resupply at sea; every one fired at a whale was one not available for a tanker. But the alternative to occasionally attacking the wrong thing is hesitating over the right one, and a submarine commander who waits until he is certain generally waits until the target has gone. The Royal Navy was reasonably relaxed about honest misidentification and extremely unrelaxed about missed opportunities, and the men in the control room knew it.

Genuine Successes Amid the Comedy

Trespasser's record was not all whale-hunting. She engaged the German auxiliary patrol vessel Uj 6073, also known as Nimeth Allah, without success, but sank the Italian auxiliary patrol vessel V8, or Filippo, by gunfire, and damaged the Japanese auxiliary gunboat Eifuku Maru off Burma with a torpedo attack, solid results in two very different theatres of the war.

The best documented of those is worth setting down properly. On 13 July 1943 she sank the Italian auxiliary patrol vessel V8, formerly the Filippo, a vessel of 242 tons, by gunfire, about twenty-five nautical miles south of Bastia on the east coast of Corsica. Two things follow from the word gunfire. The first is that she surfaced to do it, in daylight, within sight of an enemy-held island, which meant running the gun crew up through the hatch and accepting several minutes in which she could not dive quickly. The second is that a 242-ton patrol boat was not worth a torpedo, and everybody involved knew that too.

Her range was remarkable even by the standards of a class that went everywhere. In December 1942 she was working the North Cape, covering the Arctic convoy route, which is an unusual job for a submarine and a thoroughly unpleasant one: a British boat stationed off northern Norway in December sits in the dark, in ice-forming conditions, waiting for German heavy ships to come out. By the summer of 1943 she was off Corsica. By the end of the war she was off Burma putting a torpedo into the Japanese auxiliary gunboat Eifuku Maru. Three theatres, and HMS Tally-Ho will tell you what the last of them was like.

A Long, Quiet Retirement

HMS Trespasser survived the war and continued in service for well over a decade afterwards before finally being scrapped at Gateshead on 26 September 1961, closing out the career of a submarine whose most retold story will likely always be the day her crew declared war on a whale.

Sixteen Years After the War

She was not scrapped with the rest of them and that is worth a look. The Royal Navy came out of 1945 with far more submarines than it needed and disposed of most of them inside five years, keeping the newest and the best built. Trespasser was kept, and she spent sixteen further years doing the work that filled the postwar submarine service: training the anti-submarine forces, working up new crews, and exercising against a Soviet threat that had replaced the German one almost without a pause. HMS Truncheon carries the story of the eight T boats that were cut in half and rebuilt for that job. Trespasser was not one of them and carried on much as she was.

The peacetime submarine service was not safe. HMS Truculent, from the same class, was run down in the Thames Estuary in January 1950 and sixty-four men died. On 16 April 1951 HMS Affray sailed from Gosport with seventy-five aboard and did not report again, and the search that followed drew in twenty-six ships from four navies, several of them submarines. A press photograph survives of Trespasser at sea captioned as having been taken during that search, which is a single piece of evidence rather than a service record, but it puts her in the right water at the right time and it is the sort of job every available boat was given.

Affray was found on 14 June near the Hurd Deep, north of Guernsey, when a camera lowered from HMS Reclaim picked out a brass handrail and then her name at two hundred and fifty-eight feet. HMS Loch Fyne had made the first contact. She remains the last Royal Navy submarine lost at sea, and the cause has never been settled beyond a suspicion about a fractured snorkel mast.

Trespasser went to the breakers at Gateshead in September 1961, nineteen years after she was launched and sixteen after the war she was built for. She had fired at a whale, shelled a 242-ton patrol boat off Corsica, watched for German raiders in the Arctic dark and torpedoed a gunboat off Burma, and then spent the larger part of her life letting other people practise hunting her. It is not a bad career. It is simply that the whale is the bit anybody remembers.