Escort Aircraft Carrier Yamashio Maru
Escort aircraft Carrier Yamashio Maru class: Imperial Japanese Army project
The Imperial Japanese Navy and the Imperial Japanese Army had several conflicts of interest before and during the Pacific War. The Imperial Japanese Army, in addition, was always reluctant to the idea of air naval power projection. However, after the succeeds of the Combined Fleet led by the 1st Air Fleet composed of six fleet carriers during the fist half year of the Pacific War, the Imperial Japanese Army started to consider seriously to acquire their own escort carriers for air naval power support on landing assaults operations. To that end, in 1942 they transformed and re-built two passengers liners such as Akitsu Maru and Nigitsu Maru into escort carriers or what they were called by the Imperial Japanese Army, a combined assault ship and aircraft carrier. They were considered the first assault landing ships in the naval history.
Air wing and defense systems
By 1944, the American submarines activity was very intense, and many troop convoys were attacked. In order to perform protection operations such as aerial anti-submarine cover for these transport ships, they stated to consider the conversion of partly built 2TL tankers into escort aircraft carriers. The conversion process was rough and easy: just add a 107 meters of flight deck over the existing deck, without any additional hangar construction. Because of lack of hangar, the air wing composed of eight Ki-67 would be stored on deck. Sixteeen 25 mm AA guns completed the weapon system defense.
The Ki-76 remained in service as an artillery spotter and liaison aircraft until the end of the war. Ki-76s were also used as anti-submarine aircraft, operating from the Japanese Army’s escort carrier, the Akitsu Maru and Yamashio Maru (planned) being fitted with an arrestor hook and carrying two 60 kg depth charges.
The Yamashio Maru class was expected to be composed by three escort carriers converted from Type 2TL tankers. However, only one was completed (Yamashio Maru). The Yamashio Maru could not enter in military operations because only one month after she was completed, she was sunk by aerial attack in Yokohama Bay, in February 1945.
The three sisters: Yamashiro Maru, Chigusa Maru and Zuiun Maru
The Yamashio Maru sisters were the Chigusa Maru and Zuiun Maru. Both ships were not completely transformed into carriers when the war ended. Therefore, the Zuiun Maru survived war and works were done again by civilian companies to operate as a tanker. She was scrapped on June 1964. The Chigusa Maru seems to have been sunk in 1945, probably when the construction works were still on progress, It is unclear the details. However, she could be repaired and transformed as tanker to perform civilian transport operations. She was finally scrapped in June 1963, one year before than the Chigusa Maru.