:HMS Pioneer (R76)

The Colossus-class aircraft carriers were intended to meet a shortage of naval flight decks. Their design was based on that of the {{sclass|Illustrious|aircraft carrier|1}}s, but modified to permit rapid construction in commercial yards. Pioneer was not completed to her original design; the success of the maintenance aircraft carrier {{HMS|Unicorn|I72|2}} prompted modification of the ship, whilst under construction, to an aircraft maintenance ship without aircraft catapults.Friedman, pp. 237, 239

Pioneer had an overall length of {{convert|695|ft|m|1}}, a beam of {{convert|80|ft|4|in|m|1}}, and a draught of {{convert|23|ft|m|1}} at deep load. She displaced {{convert|12000|LT}} at standard load. Each of the ship's two sets of Parsons geared steam turbines drove one propeller shaft. Steam was supplied by four Admiralty three-drum water-tube boilers operating at a pressure of {{convert|400|psi|kPa kg/cm2|0|abbr=on|lk=on}}. The turbines were designed for a total of {{convert|40000|shp|lk=in}} and gave Pioneer a speed of {{convert|25|kn|lk=in}}.Lenton, p. 107 The ship carried {{convert|3196|LT}} of fuel oil which gave her a range of {{convert|8500|nmi|lk=in}} at {{convert|11|kn}}.Hobbs, p. 73

In order to maximize space for workshops and stores, the ship's arresting gear and catapult were not fitted; two large deckhouses were added to port of the island and on the rear of the flight deck. The ship had a single hangar, {{convert|17|ft|6|in}} high. Aircraft were transported between the hangars and the flight deck by two aircraft lifts; each measured {{convert|34|x|45|ft|m|1}}.Friedman, p. 367 Two large cranes were mounted on the flight deck to move aircraft and stores to and from the flight deck. The ship carried two small self-propelled lighters to allow unflyable aircraft to be transferred between ships or to shore facilities. Bulk petrol storage consisted of {{convert|98600|impgal|l usgal}}.Hobbs, pp. 69, 73 The ship's crew totaled 854, plus 222 in her aircraft repair department.

The ship was equipped with six quadruple mounts for the {{convert|40|mm|adj=on|1}} QF 2-pounder Mk VIII gun ("pom-pom"). These gun mounts could depress to −10° and elevate to a maximum of +80°. The Mk VIII 2-pounder gun fired a {{convert|40|mm|adj=on}} shell to a distance of {{convert|3800|yd|m}} at a rate of fire of approximately 96–98 rounds per minute per barrel.Campbell, pp. 71–74 She was also fitted with 19 Bofors 40 mm guns in single mounts. The Bofors had a rate of fire of about 120 rounds per minute and a maximum range of {{convert|10750|yd|m}}.Campbell, pp. 67, 70 All of the guns were mounted on the flight deck, not in sponsons on the side of the hull like her half-sisters that were completed as aircraft carriers.Hobbs, p. 68 Each "pom-pom" mount was provided with a separate fire-control director fitted with a Type 262 gunnery radar.

Pioneer was ordered on 7 August 1942 under the name Ethalion,Lenton, p. 108 but was renamed Mars later in 1942.Colledge, p. 217 She was laid down at Vickers-Armstrong in Barrow-in-Furness on 2 December and was launched on 20 May 1944 The ship was renamed Pioneer in July 1944 after the decision had been made to convert her to an aircraft maintenance ship. and was completed on 8 February 1945.

After working up, Pioneer sailed for Australia on 30 March 1945. She arrived in Sydney on 13 May and was transferred to Manus Island, in the Admiralty Islands, on 21 June to prepare for operations off Japan. She was still there when Japan surrendered on 15 August and had repaired 24 aircraft since her arrival. Pioneer arrived in Hong Kong in late September to help with the rebuilding of the colony's infrastructure. Her sailors restored power, telephone service and repaired trains and buses. She made one trip back to Manus, but was back in Hong Kong in late November. The ship sailed for Sydney the following month and departed for the UK on 17 February 1946. Upon her arrival, she was placed in reserve. Pioneer was sold to Thos. W. Ward for scrap in September 1954 and broken up in Inverkeithing.Hobbs, pp. 68–69, 73

• List of aircraft maintenance carriers of the Royal Navy

{{Reflist|30em}}

• {{Cite book|last=Campbell|first=John|title=Naval Weapons of World War II|year=1985|publisher=Naval Institute Press|location=Annapolis, Maryland|isbn=0-87021-459-4}}
• {{Cite Colledge2006}}
• {{cite book|last=Friedman|first=Norman|title=British Carrier Aviation: The Evolution of the Ships and Their Aircraft|year=1988|publisher=Naval Institute Press|location=Annapolis, Maryland|isbn=0-87021-054-8}}
• {{cite book|last=Hobbs|first=David, Commander|title=Moving Bases: Royal Navy Maintenance Carriers and MONABs|publisher=Maritime Books|location=Liskeard, Cornwall, UK|year=2007|isbn=978-1-904459-30-9}}
• {{cite book|last=Lenton|first=H. T.|title=British & Commonwealth Warships of the Second World War|publisher=Naval Institute Press|location=Annapolis, Maryland|year=1998|isbn=1-55750-048-7}}

• [http://www.maritimequest.com/warship_directory/great_britain/pages/aircraft_carriers/hms_pioneer_d76.htm Maritimequest HMS Pioneer photo gallery]

{{1942 design aircraft carrier}}

{{DEFAULTSORT:Pioneer (R76)}}

Category:Colossus-class aircraft carriers

Category:Ships built in Barrow-in-Furness

Category:1944 ships

Category:World War II aircraft carriers of the United Kingdom

Category:Cold War aircraft carriers of the United Kingdom