Japanese aircraft carrier Kumano Maru

Kumano Maru (熊野丸) was a landing craft carrier with a full-length flight deck built for the Imperial Japanese Army (IJA) during World War II. Completed in early 1945, fuel shortages meant that the ship never became operational during the war. She was turned over to the Allies at Kure when Japan surrendered later that year. Before beginning to repatriate Japanese troops home, Kumano Maru was disarmed and modified to facilitate that mission. The ship continued to do so until she was sold for scrap in 1947.

Background and description
In March 1944 the IJA and the Imperial Japanese Navy (IJN) held a conference to decide how to better protect their merchant shipping from the heavy losses suffered at the hands of American submarines. The IJN's escort carriers had, at best, limited success in doing so thus far and the participants focused on improving the number of carriers available. The IJA proposed converting oil tankers into escort carriers and agreed to forgo any further construction of Akitsu Maru-class landing craft carriers with limited aviation facilities. The Imperial Japanese Navy Technical Department agreed to design the conversions while the Imperial Japanese Navy General Staff required that the Army's auxiliary escort carriers would be dedicated to protecting the merchant ships. The services agreed that the IJA would convert two standard Type M (military) cargo ships into landing-craft carriers with full aviation facilities, beginning with Kumano Maru. The Kumano Maru-class ships had a flush-decked configuration that displaced 8128 t at standard load,  although naval historian Hans Lengerer states that they had a standard displacement of 6314 t. The ships had an overall length of 152 m, a beam of 19.58 m  and a draft of 6.95 m. The flight deck was 110 m long, 21.5 m wide, and was fitted with a four-wire Kayaba arresting gear system. They had a single hangar that was served by a lift at the rear of the flight deck. A large crane was fitted on the rear port side of the ship. The intended air group of the Kumano Marus was to consist of eight depth-charge equipped Kokusai Ki-76 liaison aircraft. If serving as an aircraft transport, the ships could fit 18 Nakajima Ki-84 Hayate fighters on the flight deck and 17 more in the hangar.

The carriers had two Kampon geared steam turbines, each driving one propeller shaft using steam provided by three Kampon water-tube boilers. The fourth boiler cited in many sources  was a cylindrical donkey boiler for the ship's steam-powered machinery. The turbines were rated at a total of 10000 shp for a speed of 19 kn  or 20 kn. The Kumano Marus had a range of 6000 nmi at 17 kn. Their funnels were positioned on the starboard side and vented horizontally outward to keep the flight deck clear. Their bridges were located under the forward edge of the flight deck. Their crew consisted of 107 men; including embarked troops, the ships' complement numbered 1,664.

The Kumano Maru-class carriers were classified as M Type C landing ships by the IJA. They could carry up to a dozen 56 ft Toku Daihatsu-class landing craft and thirteen 46 ft Daihatsu-class landing craft in their holds that were launched on rails through two large doors in the stern.

Armament
Air defence for the carriers consisted of eight 75 mm Type 88 anti-aircraft (AA) guns on single mounts below the flight deck; three on the starboard side and five on the port side. These fired 6.5 kg projectiles at a muzzle velocity of 720 m/s. These were supplemented by six autocannon on single mounts; two on platforms in front of the flight deck and the remainder on a platform aft of the flight deck. Sources disagree whether they were Army 20 mm Type 98 guns or Navy 25 mm Type 96 guns. The Type 98 gun fired its 136 g shells at a practical rate of 100 rounds per minute, while the Type 96 gun had a rate of fire for its 250 g shells of about 110 rounds per minute.

The ships were also equipped with two single 150 mm anti-submarine mortars on platforms at the bow and stern. They fired 27 kg shells to a range of 4500 m.

Construction and career
Kumano Maru was laid down at the Hitachi Shipbuilding shipyard at Innoshima, near Kure, as a standard wartime cargo ship on 15 August 1944 and was converted into her aircraft-carrier configuration while under construction. The ship was launched on 28 January 1945 and was attacked by 13 Grumman F6F Hellcat and 14 Vought F4U Corsair fighters on 19 March during the American air raid on the Kure area. Undamaged during the attack, she was completed on 31 March. Fuel oil shortages caused the Japanese to consider removing her turbines and converting the ship's boilers to burn coal, but nothing was ultimately done. Kumano Maru never became operational during the war.

The ship was turned over to the Allies on 15 August when Japan surrendered and was disarmed. To improve her suitability for the task of repatriating Japanese forces abroad, her horizontal funnel was replaced by a vertical one and four large lifeboats was added on davits that overhung the flight deck. Kumano Maru remained on repatriation duty until she was sold for scrap to Kawasaki in 1947; demolition began at their Kobe facility on 4 November and lasted until 1 September 1948.