With her sister-ship HMS Courageous, HMS Glorious was intended to be an interim solution to the problems of providing the Royal Navy with a fast aircraft carrier force, able to keep up with the rest of the fleet
The "Large Light Cruisers"
In October 1914, the Admiralty ordered three heavily-armed, fast, shallow-draught "large light cruisers": HMS Furious, and then the two ships of the Courageous class. All were destined to become aircraft carriers. HMS Glorious was laid down at Harland & Wolff's yard in Belfast on 1 May, 1915, launched on 20 April the following year and completed as a cruiser (actually, a battle cruiser in all but name) in January 1917. The Major innovations in her design were to be found in her machinery, which was actually the powerplant of a light cruiser doubled, with the boilers increased from eight to 18, giving her a mximum speed of 32 knots.
Converted to Aircraft Carriers
Conversion of HMS Courageous and HMS Glorious to their new role started in 1923, and it was fundamental. All superstructure and fittings down to the main deck level were razed, and two superimposed hanger decks, 510 feet (155m) long were built, the uppermost opening forwards onto the forecastle deck, which now became a "flying-off" deck. Two cruciform lifts connected the two hangers with the main flight deck, which ran the length of them and protruded to the stern. HMS Courageous was completed first and put back into commission on 5 May 1928, HMS Glorious followed on 10 March 1930. There was some dispute as to how the ships should be armed; ten 5.5in guns were fitted at first, but they were later deleted in favour of 4.7in AA guns.