The Courageous class, sometimes called the Glorious class, was the first multi-ship class of aircraft carriers to serve with the Royal Navy. The three ships—, and —were originally laid down as Courageous-class battlecruisers as part of the Baltic Project during the First World War. While very fast, their minimal armour and few guns limited their long-term utility in the post-war Royal Navy, and they were laid up after the war. They were considered capital ships by the terms of the 1922 Washington Naval Treaty and were included in the total amount of tonnage allowed to the Royal Navy. Rather than scrap them, the Navy decided to convert them to aircraft carriers as permitted under the Treaty.
Furious, already partially converted during the war, began her reconstruction in 1921, before the Treaty came into effect. In an attempt to minimise air turbulence, she was given no superstructure or island. This was not entirely satisfactory, and a small island was added in 1939. Another problem was that she lacked a standard funnel; instead, her boiler uptakes ran along the sides of the ship and exhausted out of gratings on the rear of the flight deck, or at the sides of the ship if landing operations were in progress. The long ducts reduced her aircraft capacity, and the exhaust gases were as much of a problem for landing aircraft as the turbulence would have been. Her half-sisters, Courageous and Glorious, began their conversions to aircraft carriers as Furious neared completion. They drew upon the experience gained by the Royal Navy since Furious had been designed and incorporated an island with a funnel, increasing their aircraft capacity by one-third and making it safer to land.
As the first large carrier completed by the Royal Navy, Furious was extensively used to evaluate aircraft handling and landing procedures, including the first-ever carrier night landing in 1926. Courageous became the first warship lost by the Royal Navy in the Second World War when she was torpedoed in September 1939 by a German submarine. Glorious participated in the Norwegian campaign in 1940, but she was sunk by two German battleships in June as she sailed home with a minimal escort. Furious participated in many major operations during the war, including the Norwegian campaign in 1940, the Malta Convoys and Operation Torch in 1942, and airstrikes on the and other targets in Norway in 1944. The ship was worn out by 1944 and was placed in reserve status in September 1944 before being paid off in 1945 and sold for scrap in 1948.
Careers as battlecruisers
The first two ships of the class, Courageous and Glorious, spent the First World War on North Sea patrols, climaxing in the Second Battle of Heligoland Bight in November 1917. Their half-sister Furious was designed with a pair of guns—as opposed to four —but was modified while being built to hold a flying-off deck and hangar in lieu of her forward turret and barbette. She made some patrols in the North Sea before her rear turret was removed and another flight deck added. Her aircraft attacked Zeppelin sheds during the Tondern raid in July 1918.Roberts, p. 123
All three ships were reduced to reserve after the war. The Washington Naval Treaty of 1922 limited the signatory nations to a set amount of capital ship tonnage; all ships in excess of this figure had to be scrapped. Up to of existing ships could be converted into aircraft carriers, and the Royal Navy decided to use the Courageous-class ships due to their high speed. Each ship was reconstructed with a flight deck during the 1920s.Friedman, p. 97
Conversions
had been fitted during the First World War with a flying-off and landing deck, but the latter proved largely unusable because of the strong air currents around the superstructure and exhaust gases from the funnel. She was laid up after the war, but was converted to an aircraft carrier between June 1921 and September 1925. Her design was based on the very limited experience gained with the first two British carriers: , less than three years old, and , which had carried out only 143 deck landings during preliminary sea trials in 1920.Burt 2012, pp. 263–267Burt 2012, p. 252Brown, p. 252
Furiouss superstructure, masts, funnel and landing deck were removed and she was given a flight deck that extended over three-quarters of her length. This flight deck was not level; it sloped upwards about three-quarters of the way from the stern to help slow down landing aircraft, which had no brakes at the time it was designed. That era's fore-and-aft arresting gear, initially long on Furious, was not intended to stop landing aircraft—the landing speeds of the time were low enough that this was unnecessary given a good headwind—but rather to prevent aircraft from veering off to one side and potentially falling off the flight deck. Various designs for the flight deck were tested in a wind tunnel by the National Physical Laboratory which showed that the distinctive elliptical shape and rounded edges minimised turbulence. To minimise any turbulence over the flight deck, Furious was flush-decked and lacked an island, like Argus; instead she was provided with a retractable charthouse at the forward end of the flight deck.Friedman, pp. 93–95
A two-storey hangar was built under the flight deck, each level being high. The lower hangar was long by wide and the upper was . Each hangar could be sectioned off by electrically operated steel shutters on rollers. Her boilers were ducted down the side of the ship to exhaust either out of gratings at the rear of the flight deck, or, when landing operations were in progress, out of the side of the lower hangar at the rear of the ship. This solution proved to be very unsatisfactory as it consumed valuable space, made parts of the lower hangar unbearable and interfered with landing operations to a greater or lesser degree. Her original flying-off deck remained in place for use by small aircraft like fighters so that the ship could simultaneously land aircraft on the main flight deck while fighters were taking off on the lower deck and could speedily launch her aircraft from both decks. Doors at the forward end of the upper hangar opened onto the lower flying deck.Burt 2012, pp. 264–265 Two lifts (elevators) were installed to transfer aircraft between the flight deck and hangars. Two ready-use petrol tanks were provided for aircraft and the ship's boats on the upper deck. An additional of petrol were in bulk storage. The longitudinal arresting gear proved unpopular in service and it was ordered removed in 1927 after tests aboard Furious in 1926 had shown that deck-edge palisades were effective in reducing cross-deck gusts that could blow aircraft over the side.Friedman, pp. 94–95 Furiouss long exhaust ducting hampered landing operations, and restricted the size of the hangars and thus the number of aircraft that she could carry.Friedman, pp. 103, 105–106
Glorious and Courageous were converted to aircraft carriers after Furious began her reconstruction, Courageous at Devonport starting on 29 June 1924, and Glorious at Rosyth on 14 February 1924. The latter was moved to Devonport to complete the conversion after Furious was finished. Their design was based on Furious with a few improvements based on experience gained since she was designed. All superstructure, guns, and fittings down to the main deck were removed. A two-storey hangar, each level high and long, was built on top of the remaining hull; the upper hangar level opened onto a short flying-off deck, below and forward of the main flight deck. Two slightly larger lifts were installed fore and aft in the flight deck. An island was added on the starboard side with the bridge, flying control station, and funnel, as an island did not create as much turbulence as had been earlier feared. By 1939 both ships could carry of petrol.
Description
The Courageous-class ships had an overall length of , a beam of , and a draught of at deep load. These were increases of in beam and over in draught compared to their earlier incarnations as battlecruisers. They displaced at normal load and at deep load, increases of over . Their metacentric height declined from at deep load to and the ships had a complete double bottom.Roberts, pp. 64–65 In 1939, Courageous had a complement of 807 officers and ratings, plus 403 men in her air group.Burt 2012, pp. 283, 285
Their half-sister Furious was the same length, but had a beam of ,Jenkins, front endpaper and an average draught of at deep load, two feet deeper than before the conversion. She displaced at normal load and at deep load, over 3,000 long tons more than her previous displacement of at load and at deep load. Furiouss metacentric height was at deep load, a reduction of after her conversion. In 1932, Furious had a complement of 738 officers and ratings, plus 468 men in her air group.Burt 2012, pp. 266, 273
Propulsion The Courageous-class ships were the first large warships in the Royal Navy to have geared steam turbines. Arranged in two engine rooms, each of the turbines drove one of the four propeller shafts. Furiouss propellers were in diameter. The turbines were powered by 18 Yarrow small-tube boilers equally divided among three boiler rooms. The turbines were designed to produce a total of at a working pressure of .Roberts, pp. 71, 76 No significant changes to the machinery were made during the conversion process to any of the three ships, but their increased displacement reduced their speed to approximately .Friedman, p. 95
Furiouss fuel capacity was increased by during her reconstruction, which increased her range to at a speed of . The maximum fuel capacity of Courageous and Glorious was increased during the conversion to of fuel oil,Burt 2012, p. 283 giving them an endurance of at 10 kn.Friedman, p. 363
Armament
Furious retained ten of her original eleven breech-loading BL 5.5-inch Mk I guns, five on each side, for self-defence from enemy warships. They fired projectiles at a muzzle velocity of . Their maximum range was at their maximum elevation of 25°, and the rate of fire was 12 rounds per minute.Campbell, p. 40
Half a dozen QF 4-inch Mark V guns replaced her original anti-aircraft guns. Four were mounted on the sides of the flying-off deck and two on the quarterdeck.Burt 2012, p. 267 They had a maximum depression of −5° and a maximum elevation of 80°. The guns fired a high explosive (HE) shell at a muzzle velocity of at a rate of 10 to 15 rounds per minute. The guns had a maximum ceiling of , but an effective range of much less.Campbell, p. 58 The four guns on the flying-off deck were removed during trials of the lower flight deck in 1926–1927, but only two were replaced when the trials were concluded.Friedman, p. 109
Four single QF 2-pounder pom-poms were installed by 1927. During Furiouss September 1930 – February 1932 refit, her anti-aircraft outfit was changed by the substitution of two 8-barrel 2-pounder pom-pom mounts for the forward 4-inch guns on the flying-off deck removed earlier.Burt 2012, p. 276 The Mark V mount could depress to −10° and elevate to a maximum of 80°. The Mark VIII 2-pounder gun fired a shell at a muzzle velocity of to a distance of . The gun's rate of fire was approximately 96–98 rounds per minute.Campbell, pp. 71–74
The and guns were replaced during Furiouss refit in early 1939 by a dozen QF 4-inch Mk XVI guns in twin dual-purpose Mark XIX mounts. One mount each was on the former flying-off deck and the quarterdeck while the other four were mounted two per side.Burt 2012, pp. 268–269, 276 The Mark XIX mount could depress to −10° and elevate to a maximum of 80°. The Mark XVI gun fired fifteen to twenty HE shells per minute at a muzzle velocity of . Against surface targets it had a range of and a maximum ceiling of , but an effective anti-aircraft range of much less.Campbell, p. 56 Two more Mark V 2-pounder mounts were added fore and aft of the newly added island at the same time.