Space/press the ship to fire HMS Courageous was the lead ship of her class of three battlecruisers built for the Royal Navy during the First World War. Designed to support the Baltic Project championed by First Sea Lord John Fisher, the ship was very lightly armoured and armed with only a few heavy guns. Courageous was completed in late 1916 and spent the war patrolling the North Sea. She participated in the Second Battle of Heligoland Bight in November 1917 and was present when the German High Seas Fleet surrendered a year later. Courageous was decommissioned after the war, then rebuilt as an aircraft carrier during the mid-1920s. She could carry 48 aircraft compared to the 36 carried by her half-sister Furious on approximately the same displacement. After recommissioning she spent most of her career operating off Great Britain and Ireland. She briefly became a training ship, but reverted to her normal role a few months before the start of the Second World War in September 1939. Courageous was torpedoed and sunk by a German submarine later that month, going down with the loss of more than 500 of her crew.
During the First World War, Admiral Fisher was prevented from ordering an improved version of the preceding Renown-class battlecruisers by a wartime restriction that banned construction of ships larger than light cruisers in 1915. To obtain ships suitable for the doctrinal roles of battlecruisers, such as scouting for fleets and hunting enemy raiders, he settled on ships with the minimal armour of a light cruiser and the armament of a battlecruiser. He justified their existence by claiming he needed fast, shallow-draught ships for his Baltic Project, a plan to invade Germany via its Baltic coast. Courageous had an overall length of 786 feet 9 inches (239.8 m), a beam of 81 feet (24.7 m), and a draught of 25 feet 10 inches (7.9 m) at deep load. She displaced 19,180 long tons (19,490 t) at load and 22,560 long tons (22,922 t) at deep load.[3] Courageous and her sisters were the first large warships in the Royal Navy to have geared steam turbines. To save design time, the installation used in the light cruiser Champion, the first cruiser in the navy with geared turbines, was simply replicated for four turbine sets. The Parsons turbines were powered by eighteen Yarrow small-tube boilers. They were designed to produce a total of 90,000 shaft horsepower (67 MW) at a working pressure of 235 psi (1,620 kPa; 17 kgf/cm2). The ship reached an estimated 30.8 knots (57.0 km/h; 35.4 mph) during sea trials.[4] The ship's normal design load was 750 long tons (762 t) of fuel oil, but she could carry a maximum of 3,160 long tons (3,211 t). At full capacity, she could steam for an estimated 6,000 nautical miles (11,110 km; 6,900 mi) at a speed of 20 knots (37 km/h; 23 mph).[5] Courageous carried four BL 15-inch Mk I guns in two hydraulically powered twin gun turrets, designated 'A' and 'Y' from front to rear. Her secondary armament consisted of eighteen BL 4-inch Mk IX guns mounted in six manually powered mounts.[5] The mount placed three breeches too close together, causing the 23 loaders to get in one another's way, and preventing the intended high rate of fire.[6] A pair of QF 3-inch 20 cwt[Note 1] anti-aircraft guns were fitted abreast the mainmast on Courageous. She mounted two submerged tubes for 21-inch torpedoes and carried 10 torpedoes for them.
