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.
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.
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.