HMS Pioneer was a Colossus-class

Colossus class aircraft carrier

The 1942 Design Light Fleet Carrier, commonly referred to as the British Light Fleet Carrier, was a light aircraft carrier design created by the Royal Navy during World War II, and used by eight naval forces between 1944 and 2001...

 aircraft carrier

Aircraft carrier

An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

 built for the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. She was modified whilst under construction into an aircraft maintenance carrier. The ship arrived in Australia in mid-1945 to support operations by the British Pacific Fleet

British Pacific Fleet

The British Pacific Fleet was a British Commonwealth naval force which saw action against Japan during World War II. The fleet was composed of British Commonwealth naval vessels. The BPF formally came into being on 22 November 1944...

 (BPF) against Japanese

Empire of Japan

The Empire of Japan is the name of the state of Japan that existed from the Meiji Restoration on 3 January 1868 to the enactment of the post-World War II Constitution of...

 forces. She supported the BPF's attacks on the Japanese Home Islands

Japanese Archipelago

The , which forms the country of Japan, extends roughly from northeast to southwest along the northeastern coast of the Eurasia mainland, washing upon the northwestern shores of the Pacific Ocean...

 from mid-June until the end of the war in August from a base in the Admiralty Islands

Admiralty Islands

The Admiralty Islands are a group of eighteen islands in the Bismarck Archipelago, to the north of New Guinea in the south Pacific Ocean. These are also sometimes called the Manus Islands, after the largest island. These rainforest-covered islands form part of Manus Province, the smallest and...

. The ship and her facilities were used to help repair Hong Kong

Hong Kong

Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

's infrastructure in late 1945 and she returned to the UK in early 1946. Pioneer was immediately placed in reserve upon her arrival and she was sold in 1954 for scrap

Ship breaking

Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially...

.

Design, description and construction

The Colossus-class carriers were intended to meet a shortage of naval flight decks. Their design was based on that of the Illustrious-class aircraft carrier

Illustrious class aircraft carrier

The Illustrious class was a class of aircraft carrier of the Royal Navy that were some of the most important British warships in World War II...

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 prompted modification of the ship, whilst under construction, to an aircraft maintenance ship without aircraft catapult

Aircraft catapult

An aircraft catapult is a device used to launch aircraft from ships—in particular aircraft carriers—as a form of assisted take off. It consists of a track built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft, or in...

s.

Pioneer had an overall length of 695 feet (211.8 m), a beam of 80 in 4 in (24.49 m), and a draught of 23 feet (7 m) at deep load. She displaced 12000 LT at standard load. Each of the ship's two sets of Parsons

Parsons Marine Steam Turbine Company

Parsons Marine Steam Turbine Company was a British engineering company based in Wallsend, North England, on the River Tyne.-History:The company was founded by Charles Algernon Parsons in 1897 with £500,000 of capital, and specialised in building the steam turbine engines that he had invented for...

 geared steam turbine

Steam turbine

A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....

s drove one propeller shaft. Steam was supplied by four Admiralty three-drum water-tube boiler

Water-tube boiler

A water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes...

s operating at a pressure of 400 pound per square inch. The turbines were designed for a total of 40000 shp and gave Pioneer a speed of 25 knots (13.6 m/s). The ship carried 3196 LT of fuel oil

Fuel oil

Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...

 which gave her a range of 8500 nautical miles (15,742 km) at 11 knots (6 m/s).

In order to maximize space for workshops and stores, the ship's arresting gear

Arresting gear

Arresting gear, or arrestor gear, is the name used for mechanical systems designed to rapidly decelerate an aircraft as it lands. Arresting gear on aircraft carriers is an essential component of naval aviation, and it is most commonly used on CATOBAR and STOBAR aircraft carriers. Similar systems...

 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

Hangar

A hangar is a closed structure to hold aircraft or spacecraft in protective storage. Most hangars are built of metal, but other materials such as wood and concrete are also sometimes used...

, 17 in 6 in (5.33 m) high. Aircraft were transported between the hangars and the flight deck by two aircraft lifts (elevators); each measured 34 by 45 ft (10.4 by 13.7 m). Two large crane

Crane (machine)

A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...

s 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

Lighter (barge)

A lighter is a type of flat-bottomed barge used to transfer goods and passengers to and from moored ships. Lighters were traditionally unpowered and were moved and steered using long oars called "sweeps," with their motive power provided by water currents...

 to allow unflyable aircraft to be transferred between ships or to shore facilities. Bulk petrol storage consisted of 98600 imp gal (448,244.5 l; 118,413.7 US gal). The ship's crew totaled 854, plus 222 in her aircraft repair department.

The ship was equipped with six quadruple mounts for the 40 millimetres (1.6 in) QF 2-pounder Mk VIII gun

QF 2 pounder naval gun

The 2-pounder gun, officially designated the QF 2-pounder and universally known as the pom-pom, was a 1.575 inch British autocannon, used famously as an anti-aircraft gun by the Royal Navy. The name came from the sound that the original models make when firing...

 ("pom-pom"). These gun mounts could depress to −10° and elevate to a maximum of +80°. The Mk VIII 2-pounder gun fired a 40 millimetres (1.6 in) 0.91 pound (0.4127690567 kg) shell at a muzzle velocity of 1920 ft/s (585.2 m/s) to a distance of 3800 yards (3,474.7 m). The gun's rate of fire was approximately 96–98 rounds per minute. She was also fitted with 19 Bofors 40 mm autocannon

Autocannon

An autocannon or automatic cannon is a rapid-fire projectile weapon firing a shell as opposed to the bullet fired by a machine gun. Autocannons often have a larger caliber than a machine gun . Usually, autocannons are smaller than a field gun or other artillery, and are mechanically loaded for a...

 in single mounts. The Bofors fired a 0.719 pound (0.32613291403 kg) shell at a muzzle velocity of 2890 ft/s (880.9 m/s). It had a rate of fire of about 120 rounds per minute and a maximum range of 10750 yards (9,829.8 m). All of the guns were mounted on the flight deck, not in sponson

Sponson

Sponsons are projections from the sides of a watercraft, for protection, stability, or the mounting of equipment such as armaments or lifeboats, etc...

s on the side of the hull like her half-sisters that were completed as aircraft carriers. 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, but was renamed Mars later in 1942. She was laid down

Keel

In boats and ships, keel can refer to either of two parts: a structural element, or a hydrodynamic element. These parts overlap. As the laying down of the keel is the initial step in construction of a ship, in British and American shipbuilding traditions the construction is dated from this event...

 at Vickers-Armstrong in Barrow-in-Furness

Barrow-in-Furness

Barrow-in-Furness is an industrial town and seaport which forms about half the territory of the wider Borough of Barrow-in-Furness in the county of Cumbria, England. It lies north of Liverpool, northwest of Manchester and southwest from the county town of Carlisle...

 on 2 December and was launched

Ship naming and launching

The ceremonies involved in naming and launching naval ships are based in traditions thousands of years old.-Methods of launch:There are three principal methods of conveying a new ship from building site to water, only two of which are called "launching." The oldest, most familiar, and most widely...

 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.

Service

After working up, Pioneer sailed for Australia on 30 March 1945. She arrived in Sydney

Sydney

Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

 on 13 May and was transferred to Manus Island

Manus Island

Manus Island is part of Manus Province in northern Papua New Guinea and is the largest island of the Admiralty Islands. It is the fifth largest island in Papua New Guinea with an area of 2,100 km², measuring around 100 km × 30 km. According to the 2000 census, Manus Island had a...

, in the Admiralty Islands, on 21 June to prepare for operations off Japan

Japan campaign

The Japan Campaign was a series of battles and engagements in and around the Japanese Home Islands, between Allied forces and the forces of Imperial Japan during the last stages of the Pacific Campaign of World War II. The Japan Campaign lasted from around June 1944 to August 1945.-Air war:Periodic...

. She was still there when Japan surrendered

Surrender of Japan

The surrender of Japan in 1945 brought hostilities of World War II to a close. By the end of July 1945, the Imperial Japanese Navy was incapable of conducting operations and an Allied invasion of Japan was imminent...

 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 for scrap in September 1954 and broken up in Inverkeithing

Inverkeithing

Inverkeithing is a town and a royal burgh in Fife, Scotland, located on the Firth of Forth. According to population estimates , the town has a population of 5,265. The port town was given burgh status by King David I of Scotland in the 12th century and is situated about 9 miles north from...

.

External links

• Maritimequest HMS Pioneer photo gallery