Menghean Aircraft Carrier "Hangmo Il-ho" (Carrier No.1)
Length: 548 ft (167 m)
Beam: 67 ft (20.4 m) hull
Draft: 24 ft (7.32 m) at full load
Displacement: 11,030 tonnes standard
Speed: 26.2 knots
Range: 3,650 nautical miles at 12 knots
Powerplant: 6x water-tube boiler, coal-burning with oil spray
Propulsion: 2x steam turbine, 22,000shp each, 2 shafts
Armament:
- 2x1 Type 10 125mm L/50 LA gun in Type 10 mount
- 4x1 Type 16 75mm L/40 HA gun in Type 22 mount
- 6x1 Type 15 7.5mm "Magŭsim" AA machine gun
Air wing:
- 12x Gloster Type 23 Carrier Fighter (licensed Gloster Sparrowhawk)
- 12x Chanam Type 24 Reconnaissance Bomber
Boy, this was a fun one to modify last minute!
Before the scoring begins...
does anyone want to take a moment to look up when all-transverse arresting wire schemes first entered service? 
In the 1910s and early 1920s, Menghe was engaged in a naval arms race against Dayashina, its maritime neighbor across the Sea of Fuso and, at the time, its most serious geostrategic threat. Thus, when rumors emerged that Dayashina was building its first aircraft carrier, the Federal Assembly eagerly authorized construction of a Menghean aircraft carrier to keep pace. The new ship's keel was laid down on 13 March 1922, squeaking in ahead of the Selkiö Naval Treaty and securing her classification as an "experimental" vessel that would not contribute to Menghe's treaty tonnage. Despite this classification, and a number of features to facilitate experimental operations, she was in all respects a fully combat-capable vessel, and she would later go on to see service in the Pan-Septentrion War.
Rather than convert an existing tanker, oiler, warship, or liner, the Menghean Navy insisted on a keel-up design which would minimize compromises inherited from an old hull. One such optimiziation, visible from the arrangement of the funnels, is that her six large water-tube boilers are located aft of the turbines, thus keeping smoke somewhat further from the forward flight deck. Another was her cruiser-like armor scheme, with 3" armor plating over the machinery spaces, steering gear, magazines, and part of the forward waterline. This protection was chosen to prevent critical damage from destroyer- and light-cruiser-grade guns, and not much else, the idea being that shrewd planning would keep the ship out of combat. This was also reflected in the armament, with two 125mm low-angle guns on the quarterdeck to engage pursuing vessels. The other guns, at the time of construction, were high-angle only: four 75mm flak guns and six 7.5mm water-cooled machine guns.
Early design sketches proposed aircraft braking on the deck without help from arresting wires. During construction, however, the Navy concluded that current and especially future torpedo bombers would require some kind of wire-based arresting system, and began experimenting on land with systems derived from Anglian technology, quickly settling on longitudinal arresting wires as the least risky option. Crews nicknamed this system the "Gayagŭm" (a traditional zither) for the long parallel cables, which served the dual purpose of slowing down a landing aircraft through friction, and preventing it from veering too far to either side. Three ramp-like structures, which could be individually raised and lowered, elevated the wires above the decks for landing operations, and a systme of pulleys routed through the forward entry point kept adequate tension on the wires. Though primitive by comparison with the transverse arresting wires that later became ubiquitous, longitudinal wires were arguably the most mature type of arresting system of the mid-1920s.
The addition of the arresting system obstructed the initial planned location of the aft elevator. Because planking this over would seriously hinder the launching and recovery rate, and relocating it aft would require shrinking it and imposing other changes, in the end the designers chose to move it further forward, creating a 150-foot-long arresting space positioned nicely toward the end of the flight deck. With the erection of a safety net amidships, it became possible to conduct launch and recovery operations simultaneously; with an aft safety net erected and only the rear section of the arresting array raised, it was even possible to recover the lightest fighters while using the rear elevator, though in practice this was risky and seldom done.
One feature not altered between design and completion was the flat, washboard-like flight deck. The navigation bridge was situated in an enclosed arc suspended under the flight deck, with protruding wings on either side; flight operations were overseen from a platform on the starboard side of the flight deck. Visibility from both was quite poor, and a watch station on the main mast was not usable while the mast and radio lines were folded down. On the plus side, the lack of protruding funnels and islands did reduce the collision risk for new pilots.
An open hangar was chosen in order to allow aircraft to run up their engines before being brought up to the flight deck. In addition to benefiting the average sortie generation rate, this would allow test-runs of engines while at sea, useful in testing and maintenance. A further advantage of the open hangar is that it allowed more generous growth margins in the event that newer aircraft might be brought into service, or at least trialed temporarily aboard the Il-ho.
At the time of commissioning, the air wing consisted of Type 23 Carrier Fighters, licensed versions of the Gloster Sparrowhawk, and Chanam Type 24 Reconnaissance Bombers, a domestic design. Both were fitted with distinctive horizontal bars forward of the landing gear, under which were hooks to snag the parallel arresting wires. The Type 23s did not have folding wings, but their small wingspan reduced their hangar footprint, and the relocation of the aft elevator further forward enabled parking changes which raised the size of the initial air wing from ten to twelve fighters. The Chanam Type 24 did have folding wings, and with wings folded, it was possible to park two of them on the aft elevator. The forward elevator was likewise long enough to bring up two Type 23s, or one Type 24 with wings folded.
This twin-plane-on-elevator layout was actually found to be inefficient in early service, because Menghean carrier doctrine of the time stressed immediate strikedown of landing aircraft, with all servicing and rearmament taking place inside the hangar. Along with the open hangar, well-positioned twin elevators, and below-deck warmups, this allowed higher sortie generation rates on average, because the deck was generally kept clear for new aircraft coming in to land. The tradeoffs of this doctrine included a reduced air wing size, because of the lack of provisions for deck parking, and a reduced "surge" generation rate, because it was cumbersome to amass a large number of aircraft on the flight deck in preparation for a large strike. This tradeoff reflected early Menghean Navy assumptions about the role of carrier aircraft, which emphasized reconnaissance, local air patrol, and small strike packages launched on a rolling bases, rather than massed airstrikes involving a large share of the serviceable strike wing. Though defensible in the early 1920s, these assumptions had become hard-wired into Menghean doctrine and carrier design by the late 1930s, hampering the Menghean Navy's transition to carrier-centric naval warfare.
