Glorious in Plymouth Sound in 1935, after catapults and arrester wires had been fitted. Anti-aircraft guns have been mounted on the former flying-off deck. The long structure to port of the island was a bridge extension, intended to give the captain and navigating officer a view to port in pilotage waters. It was folded back flush with the island at sea during flying operations. (AUTHOR’S COLLECTION)
Technical background
Both ships saw service as light battlecruisers with the Grand Fleet, and some early thought was given to converting them into aviation ships like their half-sister Furious, but nothing was done until after the war. They were saved from the scrapyard by a decision taken by the Admiralty in 1920 to convert them into flush-deck aircraft carriers similar to Furious, and a team of constructors under J H Narbeth worked out the detailed redesign, which took advantage of the early experience with Argus and Eagle.
Even before Furious was completed it was clear that the trunked funnel arrangements and lack of an island were not successful, although the latter did allow aircraft with large wingspans to land-on without obstruction. Against that single positive, the trunking added about 200 tons in weight high in the ship, reduced the amount of workshop space available and reduced the number of aircraft that could be struck down into the upper hangar by about ten. The temperature near the ducts was found to reach 63 degrees Celsius (or 146 degrees Fahrenheit), and made the after end of the ship hot, dirty and, at times, intolerable. The lack of an island made ship control difficult and made it difficult to find space for aerials, offices and aircrew briefing or ready rooms.
The idea of an island and funnel arrangement was first considered by Narbeth to make space for 8in gun turrets and their ammunition-hoist arrangements, to match similar weapons reported on American and Japanese carriers. Their advantages were deemed to be so great, however, that they were retained when the big guns were deleted from the design. Although the small island was important for ship and flying control, the trunked funnel gave the biggest advantage, and Narbeth referred to these ships at first as ‘funnel carriers’.
The same double-hangar arrangement as Furious was adopted as a means of stowing the maximum number of aircraft in a relatively small hull. Deck parking was still not considered an option, as the relatively lightweight aircraft of the era could easily suffer wind damage even when lashed on deck. Without the trunking making inroads into the upper hangar, these two later ships were able to carry a useful air group of forty-eight aircraft as well as having more extensive workshop arrangements. The same cruciform lifts as those in Eagle and Hermes were fitted fore and aft. Like Furious, both ships had a flying-off deck over the forecastle connected to the upper hangar, from which fighters could be launched when the main deck was filled with parked aircraft. Windbreaks, which lay flush with the deck when not in use, were fitted at the forward end of both decks to protect aircraft ranged behind them as the ships accelerated into wind before starting a launch. With increasing aircraft weights leading to longer take-off runs the forward deck was no longer used after 1935, and the doors on to it from the upper hangar were welded shut.
A Swordfish lands on Glorious while others join overhead in formation. The ‘W’ shaped bracket under the extended round- down is a distinctive recognition feature for this ship, but the letters GL painted on the after part of the flight deck confirm her identity. (AUTHOR’S COLLECTION)
Courageous was the first British carrier to be fitted with transverse arrester wires when she carried out flying trials of various different types in 1930. Both ships were fitted with production Mark III arrester wires from 1933, but neither was ever fitted with a barrier. At first there was some resistance to the new techniques in Courageous until Admiralty experts pointed out the marked improvement in landing intervals that followed the introduction of arrested landings and explained the progress that had been made by the US Navy. Both ships were also fitted with catapults, intended at first for launching aircraft fitted with floats. The potential for catapulting the first aircraft out of a large range to increase the number of aircraft on deck beyond the amount of deck that would be
needed for a free take-off was not appreciated until some years later. At the time the RN differentiated between catapults fitted in battleships, cruisers and specialised catapult ships and those fitted in aircraft carriers, the latter being referred to as accelerators. With the rapid disappearance of seaplane flights after 1943 the term catapult was applied universally and is used so throughout this work. The catapults fitted in Courageous and Glorious could launch an 8,000lb aircraft at an end speed of 56 knots or a 10,000lb aircraft at 53 knots. All naval aircraft of the 1930s were designed to operate either with wheels or floats, so that they could operate from either aircraft carriers or battleships and cruisers equipped with catapults. The aircraft floats were stressed to allow deck landings, although the metal-to-metal contact with the deck cannot have been good for either structure if carried out frequently.
Courageous as converted. (©JOHN JORDAN 2010)
The after ends of the two ships’ flight decks were significantly different, and were a useful recognition feature by which they could be told apart. Courageous’ flight deck ended abruptly with a very short round-down at the after end of the hangar, and she had a seaplane handling deck built up above the quarterdeck. Glorious had a longer round-down that extended right aft, supported by a large W-shaped bracing at the after end of the quarterdeck. Her seaplane handling deck was lower, level with the lower hangar deck. Both ships had derricks for lowering seaplanes on to the water, these being folded flush with the after hangar bulkhead when stowed. There was more space in both ships for workshops than in Furious and they were relatively well equipped. Whatever their demerits, this class gave the RN the opportunity to evaluate the operation of relatively large numbers of aircraft in manoeuvres at sea, especially when two or more carriers operated together.
The sea water washing down Glorious’ flying-off deck and crashing into the hangar door show the disadvantage of the design in rough weather. (AUTHOR’S COLLECTION)
Both ships were originally completed with a main armament of four 15in guns in twin turrets, one forward and one aft. When the guns and mountings were removed they were kept in storage and eventually refurbished to equip the battleship Vanguard (those from Courageous being mounted forward and those from Glorious aft). Early in the carrier-conversion design process a number of options were considered for gun armament, including, as mentioned before, 8in weapons to match similar designs in other navies and provide a defence against cruisers. In the event they were fitted with twelve single 4.7in high-angle guns intended mainly for use against aircraft in barrage fire. They were controlled by four directors, two on each side just below the flight deck. Once the lower flight deck ceased to be used by aircraft, two eight-barrelled ‘pom-poms’ were mounted on it, and a third was mounted on the flight deck aft of the island in the late 1930s. Both ships had fittings for multiple machine guns for close-range defence against strafing aircraft.
The biggest design weakness of the class was that they had ‘grown upwards’ from light cruisers and not ‘downwards’ from a capital ship design. The protective arrangements could not be described as a cohesive system and had been designed and applied piecemeal. They were inadequate against the weapons deployed against them in 1939.
Courageous Class technical details
Displacement: 27,560 tons deep load
Dimensions: length 786ft 6in beam 11 Oft draught 28ft
4 shaft Parsons geared turbines 18 Yarrow small-tube boilers 90,670shp
Machinery: delivering 30 knots
Armament: 16 single 4.7in QF Mark VIII HA (12 in Glorious); 4 single 3pdr; machine guns Procection: 3in side belts; 3in forward and 2in aft bulkheads; 1.75in over machinery and
steering gear; ant-torpedo bulges designed to defeat 440lb warheads
Fuel: 3,685 tons FFO
Endurance: 2,920 miles at 24 knots
Complement: 1,260
Aircraft operating data
Flight deck: 530ft × 91 ft 6in steel plate
Hangars: upper 550ft × 50ft × 16ft lower 550ft × 50ft × 16ft
Catapults: 2 hydraulic, 10,000lbat 52 knots
Arrester wires: 4x 11,0001b ae 53 knots
Lifts: forward 46ft × 47ft cruciform aft 46ft × 47ft cruciform
Aircraft: 48
Aircraft fuel: 35,700gal avgas
Air weapons:
18in torpedoes; 5001b SAP bombs; 2501b SAP bombs; 2501b GP bombs; 1001b bombs; 1001b A/S bombs; 201b bombs; 0.303in machine-gun ammunition; flares and pyrotechnics