HMS Ark Royal (pennant number 91) was an aircraft carrier of the Royal Navy that operated during the Second World War.

Designed in 1934 to fit the restrictions of the Washington Naval Treaty, Ark Royal was built by Cammell Laird at Birkenhead, England, and completed in November 1938. Her design differed from previous aircraft carriers. Ark Royal was the first ship on which the hangars and flight deck were an integral part of the hull, instead of an add-on or part of the superstructure. Designed to carry a large number of aircraft, she had two hangar deck levels. She was used during a period that first saw the extensive use of naval air power; several carrier tactics were developed and refined aboard Ark Royal.

Ark Royal operated in some of the most active naval theatres of the Second World War. She was involved in the first aerial U-boat kills of the war, operations off Norway, the search for the German battleship , and the Malta Convoys. Ark Royal survived several near misses and gained a reputation as a 'lucky ship'. She was torpedoed on 13 November 1941 by the and sank the following day. One of her 1,488 crew members was killed. Her sinking was the subject of several inquiries, with investigators keen to know how the carrier was lost in spite of efforts to save the ship and tow her to the naval base at Gibraltar. They found that several design flaws contributed to the loss, which were rectified in subsequent British carriers.

The wreck was discovered in December 2002 by an American underwater survey company using sonar mounted on an autonomous underwater vehicle, under contract from the BBC for the filming of a documentary about the ship, at a depth of about and about from Gibraltar.

Design In 1923, the Admiralty prepared a 10-year building programme which included an aircraft carrier and 300 aircraft for the Fleet Air Arm. The economic downturn following the First World War caused it to be postponed. In 1930, the Director of Naval Construction, Sir Arthur Johns, began to update the plans for the carrier by incorporating recently developed technology. His aim was to increase the number of aircraft carried by shortening the landing and take-off distances of aircraft using arrestor gear and compressed steam catapults respectively, which would make more deck space available for storage and aircraft preparation. Along with the inclusion of two hangar decks, this allowed Ark Royal to carry up to 72 aircraft, although the development of larger and heavier aircraft during the carrier's construction meant that the actual number carried was between 50 and 60. Ark Royal featured an enclosed hangar design where the flight deck was the 'strength deck' and was strongly built with 0.75in (19mm) thick Ducol steel plating. The two hangar decks were thus enclosed within the hull girder, which also gave splinter protection to the hangars. The machinery spaces were protected by belt armour. Three lifts moved aircraft between the hangars and the flight deck.

Another feature was the length and height of the flight deck. At , the flight deck was longer than the keel; the latter dictated by the length of Royal Navy drydocks in Gibraltar and Malta. Due to the twin hangar decks, the flight deck rose to above the waterline.

The Washington and London Naval treaties had restricted warship displacement for a number of nations after the end of the Great War and were both to expire by the end of 1936. With a potential naval arms race developing between Britain, Japan and Italy, the British government sought a second treaty, which included limiting the maximum displacement of an aircraft carrier to . Ark Royal would have to fit this anticipated limit; to conserve weight, armour plating was limited to the belt, engine rooms, and magazines, while welding instead of rivetting 65% of the hull saved . Installation of an armoured flight deck was not possible, as the weight would have placed Ark Royal above the proposed limit, while reducing her endurance and stability. The ship was designed with a three-layer side protection system based upon a void-liquid-void scheme very similar to that used on the King George V-class battleships, and was designed to protect against torpedoes with up to a warhead.

The ship was fitted with six boilers, which powered three Parsons geared turbines. The turbines were connected via three driveshafts to three propellers in diameter, to produce a maximum theoretical speed of . Speed was important, as with catapults and arrestor gear, Ark Royal would have to turn into the wind to launch and recover aircraft. To avoid endangering other ships with the frequent course changes associated with flight operations, Ark Royal would have to break away from accompanying ships, and catch up on completion. Additionally, as the carrier was not armed for ship-to-ship combat, speed was her main protection against enemy warships.

Construction The deteriorating international situation by 1933, typified by Germany's rearmament and the expansion of Japan and Italy, convinced the British to announce funds for the carrier's construction in the 1934 budget proposals. The plans were finished by November 1934 and were tendered in February 1935 to Cammell Laird and Company, Ltd, which calculated the cost of the hull at £1,496,250 (equivalent to £ in ) and the main machinery at about £500,000 (equivalent to £ in ). The overall cost was estimated to be over £3 million (equivalent to £ in ), making Ark Royal the most expensive non-battleship ordered by the Royal Navy. Construction began on Job No. 1012 when Ark Royals keel was laid down on 16 September 1935.

Ark Royal spent nearly two years in the builder's yard before being launched on 13 April 1937 by Lady Maud Hoare, wife of Sir Samuel Hoare, then First Lord of the Admiralty. The bottle of champagne thrown against Ark Royals bows did not smash until the fourth attempt. The carrier spent a year fitting out, was handed over to her first commander, Captain Arthur Power, on 16 November 1938, and was commissioned on 16 December. Although intended for the Far East, events in Europe during the carrier's construction, including the Italian invasion of Abyssinia in 1935 and the Spanish Civil War in 1936, caused the Admiralty to mark her for deployment with the Home and Mediterranean Fleets. After her crew joined at the end of 1938, Ark Royal underwent sea trials to prepare for service, during which the carrier proved capable of sailing above her theoretical speed, reaching over 31 knots (57.4 km/h; 35.6 mph) and in trials during May 1938 Ark Royal achieved with at a deep displacement of .Friedman, p. 123

Armament and aircraft Ark Royals armament was designed with anti-aircraft warfare in mind, as aircraft were expected to be the main threat; ships and submarines could be outrun or dealt with by escorts. Her main armament was sixteen quick-firing 4.5-inch (113 mm) dual purpose guns in eight twin turrets, four on each side of the hull, controlled by four Directors using the High Angle Control System. The original design placed the turrets low on the hull, but was later altered to locate them just below the flight deck, which increased each turret's field of fire. SixFriedman, 1988, Appendix A. 8-barrelled QF 2-pounder "pom-pom" gun mounts were located on the flight deck, in front of and behind the superstructure island, while eight 4-barrelled Vickers machine guns were installed on small projecting platforms to the front and rear of the flight deck.

Sixteen Fleet Air Arm squadrons were posted aboard Ark Royal during her career; an average of five squadrons at any time. On entering service, most of Ark Royals squadrons were equipped with either Blackburn Skuas—used as fighters and dive bombers—or Fairey Swordfish, for reconnaissance and torpedo bombing. From April 1940, squadrons equipped with Skuas were upgraded to Fairey Fulmars; like their predecessors, these were used as fighters and bombers. On occasion, the carrier operated Blackburn Roc fighter-bombers (from April 1939 – October 1940) and Fairey Albacore torpedo bombers (during October 1941); these were replacement aircraft used to boost squadron numbers. In June 1940, Ark Royal was host to 701 Naval Air Squadron, a training squadron which operated Supermarine Walrus reconnaissance amphibians.

+ Squadrons embarked aboard Ark RoyalSquadronAircraft operatedEmbarked (from – to)Notes800 Blackburn Skua Mk. II January 1939 – April 1941 Transferred to 810 Fairey Swordfish Mk. I January 1939 – September 1941820 Fairey Swordfish Mk. I January 1939 – June 1941 –821 Fairey Swordfish Mk. I January 1939 – April 1940 Removed from operational service following losses against Scharnhorst803 Blackburn Skua Mk. II Blackburn Roc Mk. I April 1939 – October 1940 –818 Fairey Swordfish Mk. I August–October 1939 June–July 1940 Operated from and land bases between October 1939 and June 1940801 Blackburn Skua Mk. II April–May 1940 Transferred to Furious807 Fairey Fulmar Mk. II April–November 1941 Embarked at sinking701 Supermarine Walrus Mk. I June 1940 Training squadron808 Fairey Fulmar Mk. II September 1940 – November 1941 Embarked at sinking821X Fairey Swordfish Mk. I December 1940 – January 1941 Flight assembled from 821 Squadron survivors, later absorbed into 815 Squadron800Y Fairey Fulmar Mk. I June 1941 Flight from 800 Squadron825 Fairey Swordfish Mk. I June–November 1941 Embarked at sinking816 Fairey Swordfish Mk. I July–November 1941 Embarked at sinking812 Fairey Swordfish Mk. I September–November 1941 Embarked at sinking828 Fairey Swordfish Mk. I Fairey Albacore Mk. I October 1941 Redeployed to Malta

Service history

With the hunter-killer groups

The outbreak of the Second World War on 1 September 1939 had been presaged by Germany's U-boat fleet taking up positions off the British coast, where they could intercept British shipping. Within hours of Britain and France declaring war on Germany, the passenger ship was torpedoed by , the first of over 65,000 tons of shipping sunk by U-boats during the first week of the war. Ark Royal was deployed with the Home Fleet in the North Western Approaches as part of a "hunter-killer" group, consisting of a flotilla of destroyers and other anti-submarine vessels grouped around an aircraft carrier; either , or Ark Royal. Carrier-borne aircraft could increase the area searched for U-boats, but made the carriers tempting targets.

On 14 September, Ark Royal received a distress call from , which was away under pursuit from the surfaced U-30. Ark Royal launched aircraft to aid the merchant ship, but was spotted by , which launched two torpedoes. Lookouts spotted the torpedo tracks and Ark Royal turned towards the attack, reducing her cross-section and causing the torpedoes to miss and explode harmlessly astern. Three F-class destroyers escorting the carrier began to depth charge U-39, and forced her to the surface. The German crew abandoned ship before U-39 sank—the first U-boat lost during the war. Ark Royals aircraft reached Fanad Head, which was in the hands of a German boarding party. The Skuas unsuccessfully attacked U-30: two crashed when caught by the blast of their own bombs. The U-boat escaped after rescuing the boarding party and the pilots of the downed aircraft (both observers had drowned), and torpedoing the Fanad Head.

Ark Royal returned to base in Loch Ewe, where she and her crew were inspected by Winston Churchill. The sinking of U-39 was hailed as important to morale. However, the failed attack on Ark Royal, and the successful attack on Courageous on 17 September, convinced the Admiralty it was too dangerous to risk aircraft carriers in this way, and carrier-centred hunter-killer groups were abandoned.

Another near miss