My entry, the Insuperable Class.
HMS Insuperable, May 1941
The successor to the Ark Royal completed in 1938 were two similar ships built as replacements for HMS Eagle and HMS Hermes. They were modified from the basic Ark Royal design with a longer hull, revised hangar arrangements and a new machinery layout with four propeller shafts. While the idea of the armoured carrier gained ground, it was decided that maximum capacity of aircraft was desired over wasting precious tonnage given the treaty tonnage limits then in force. Insuperable completed shortly before the war and was one of the best carrier designs then afloat. In the meantime it had been planned to order another four near-repeats as the Illustrious class.
HMS Insuperable gained the honour of being the first carrier to sink another carrier during the Operation Rheinübung in May 1941. The battleship Bismarck had broken out from the North Sea in concert with the carrier Graf Zeppelin and the crusier Prinz Eugen. Graf Zeppelin's aircraft managed to cripple the cruiser HMS Norfolk off Greenland but was intercepted by a force from Scapa Flow including HMS Hood, the new HMS Prince of Wales and HMS Insuperable.
Insuperable had aboard 30 Fairey Swordfish torpedo-bombers, 12 Fairey Fulmar two-seat fighters and rushed aboard 6 new Fairey Barracuda torpedo bombers powered by the Rolls-Royce Exe engine and 12 new Fairey Petrel fighters powered by the Rolls-Royce Griffon. In the first attack in the Battle of the Denmark Strait her aircraft sank the Graf Zeppelin, the Barracuda's new magnetic pistol torpedoes failed but the Swordfish did their work in two waves of attacks. The Petrel proving a match for the Bf 109 fighters trying to protect their carrier. Bismarck was also crippled and this allowed the rest of the Home Fleet to engage, HMS Victorious adding her airpower into the battle. Ultimately Bismarck was pounded to destruction by the battleships but Prinz Eugen was also hunted down and sunk by the combined airwings.
Drawing Note: I have always wanted to do a Batch II Ark Royal and this is the result, she takes cues from Ark herself as well as Illustrious several other 1930s carrier projects for commerce protection carriers that were never built. The result is something more akin to a 'British Essex' and in my AU no less than 9 of double-hangar carriers would be built (Ark, 2 Insuperables, 4 Illustrious, 2 Indomitables).
The Barracuda is of course the original design planned for the 24-cylinder air-cooled Exe and the Petrel is a real project to N.9/39 which was instead built as the 2-seat Firefly.
2 ships commissioned:
HMS Insuperable 16 July 1939
HMS Invincible D33 22 February 1940
23,000 tons standard
785ft (oa), 725ft (wl) length; 95ft (hull), 105ft (flightdeck) beam; 25ft draught (standard displacement)
110,000shp steam turbines powering 4x shafts
7,800 nautical miles at 20kts
6x2 4.7in/45 Mk.X (400 rpg) in BD Mk.II turrets
7x8 2pdr pom-poms (1,000 rpg)
8x4 0.5in Vickers machine-guns
Upper hangar 550ft long; 60ft wide; 16ft high; capacity for 36 aircraft
Lower hangar 460ft long; 60ft wide; 16ft high; capacity for 30 aircraft
Dark park: 6 permanent parking positions
Total capacity: 72 aircraft (as designed)
Flight Deck Equipment
2x BH.I hydraulic accelerators (from 1941 replaced by 1x BH.III unit)
6x arrester wires (from 1942 upgraded to 9x wires)
2x crash barriers
3x 45 x 22ft elevators (serving all 3 hangars)
Belt: 4.5in (closed by 4.5in bulkheads)
Deck: (lower hangar floor) 3.5in over boiler rooms, machinery spaces and magazines
Flight deck: strengthened plating equal to 1in thickness armour
Rudder space: 3in 'box' protection
Torpedo protection: double space bulkheads
2x Type 79 air search (transmit and receive aerials)
2x Type 285 on HACS directors for 4.7in guns
7x Type 282 pom-pom barrage fire directors