HMS Pioneer (R76): The Aircraft Carrier That Never Actually Flew Aircraft

Three Names Before She Even Launched

Few ships change their minds about who they are quite as often as HMS Pioneer did before she ever touched water. Ordered from Vickers-Armstrong's yard at Barrow-in-Furness in August 1942 under the name Ethalion, she was renamed Mars later that same year, and renamed again to Pioneer in July 1944, just months before her launch.

She was laid down on 2 December 1942, finally launched on 20 May 1944, and commissioned on 8 February 1945, one of the Colossus-class light fleet carriers rushed into service to give the Royal Navy the hulls it needed to fight a global war.

The three names are less of a muddle than they look. Ethalion and Mars were ordinary fighting-carrier names from the Colossus programme, given to a ship nobody had yet decided anything unusual about. Pioneer arrived in July 1944, and it arrived because the Admiralty had by then settled what she was actually going to be. The renaming was the announcement.

A Carrier Built Not to Launch Aircraft

What made Pioneer unusual was not her class but her job. The success of HMS Unicorn, an earlier aircraft maintenance carrier that had proved just how useful a floating repair shop could be to a fleet operating thousands of miles from the nearest proper dockyard, prompted the Admiralty to convert Pioneer to the same specialised role while she was still under construction.

She was completed without catapults or arresting gear, the very equipment that defines a conventional carrier's ability to launch and recover aircraft, because launching and recovering aircraft was never going to be her job. Instead, her hangars and workshops were built to receive damaged and worn-out aircraft, patch them up, and send them back to the fleet's fighting carriers ready to return to combat.

The ship that proved the idea has an article of her own: HMS Unicorn (I72) was designed from the keel up as an aircraft repair ship and demonstrated, once she got to sea, that a fleet working a long way from a dockyard needs somewhere to mend its aeroplanes rather more urgently than it needs another flight deck. Pioneer and her sister Perseus were the follow-on, converted on the slipway rather than designed from scratch, which is why they ended up as carriers with hangars full of lathes.

Keeping the British Pacific Fleet Flying

Pioneer left Britain on 30 March 1945 under her first captain, H.S. Murray-Smith, and reached Sydney by mid-May, before moving on to the forward base at Manus Island in the Admiralty Islands that June, right in the operational heart of the British Pacific Fleet's push against Japan. That same month Murray-Smith was promoted commodore and hoisted his broad pennant aboard her, making Pioneer the flagship of the newly formed Commodore Air Train organisation, the fleet's floating aircraft supply and repair headquarters.

Anchored off Pityilu Island in the Admiralties, she carried out exactly the quiet, essential work she had been built for, repairing twenty-four Corsairs and Avengers in eight weeks, aircraft that would otherwise have been written off or left waiting weeks for repairs back in Australia, keeping the fleet's strike squadrons closer to full strength during the final, intense months of the Pacific war.

Commodore Air Train deserves a sentence, because it was a new thing rather than a new name for an old one. The British Pacific Fleet was the first fleet the Royal Navy had ever had to keep supplied at that sort of distance, and it had to invent the whole apparatus from almost nothing: tankers, store ships, repair ships, escort carriers ferrying replacement aircraft, and for the aeroplanes themselves a floating maintenance organisation with a commodore of its own. Pioneer was its flagship. Twenty-four Corsairs and Avengers in eight weeks does not sound like a great deal until you consider the alternative, which was putting each of them on a ship back to Australia and waiting.

Japan's surrender came on 15 August 1945, bringing that particular chapter of her service to a close.

Hong Kong, Then Home to Reserve

Pioneer's usefulness did not end with the war. She arrived at Hong Kong in early September 1945 to assist with the colony's reconstruction after years of Japanese occupation, and her engineers turned their hands to restoring power, water and sanitation systems across the battered territory, a role that made good use of a ship already equipped with substantial workshop and repair facilities, even if those facilities had originally been designed with aircraft rather than a shattered civilian infrastructure in mind.

Even her final leg home had one more job to do. Sailing from Hong Kong for Sydney at the end of November 1945, she was diverted to Bougainville to evacuate 270 military personnel, a last piece of unglamorous, useful work before command passed to Captain G.R. Deverell in January 1946, her Commodore Air Train duties handed on to HMS Perseus.

She returned to Britain on 17 February 1946 and was placed in reserve, her wartime job well and truly finished.

A Quiet End

Pioneer never returned to active service. She sat in reserve for the best part of a decade before being sold to Thos. W. Ward for scrap in September 1954 and broken up at Inverkeithing, a modest end for a ship whose entire career had been defined by supporting other vessels rather than fighting alongside them.

The Catapult That Came Out of a Repair Ship

There is a coda that belongs properly to her sister, and it is much the largest thing either of them did. HMS Perseus, who took the Commodore Air Train job over from Pioneer in 1946 and was otherwise as obscure a ship as this one, was chosen in 1950 to test a prototype. Commander Colin Mitchell of the Royal Naval Volunteer Reserve had designed a slotted-tube catapult driven by steam instead of by the hydraulics and cordite charges everybody had used until then, and somebody had to find out whether it worked.

It was fitted into a new structure on her deck early in 1951, and she spent the year firing things off the front of it: dead loads first, gradually heavier, then surplus airframes with their wings off and no engines running, then real aircraft of nearly every type in service. One thousand five hundred and sixty launches, and not one mishap.

In January 1952 she took it to Philadelphia to show the Americans. They asked whether the thing would stand their own much higher-pressure steam, and then moored the destroyer USS Eugene A. Greene alongside and piped it aboard to find out. It would. The United States Navy adopted the design that April, put the first one in USS Hancock, and on 1 June 1954 a Grumman Tracker was thrown off Hancock's bow in the first American steam catapult launch. Every catapult on every conventional aircraft carrier in the world since is descended from a piece of ironmongery bolted to the deck of a converted aircraft repair ship.

Neither Pioneer nor Perseus ever launched an aircraft off her own deck in operational service. One of them quietly changed the way every other carrier in the world does it.

The Unsung Value of a Repair Ship

It is easy to overlook a ship like HMS Pioneer when the history books are full of carriers that launched the strikes and won the headlines. But an aircraft maintenance carrier's contribution was just as real: every aircraft she patched up and returned to service was one less gap in a fighting carrier's squadron, one more strike aircraft available when it mattered.

Pioneer never flew a single sortie of her own, but the fleet she supported flew rather better for her being there.