I.J.N. light aircraft carrier “Ryūjō”, c. 1935.

I.J.N. light aircraft carrier Ryūjō, c. 1935, as originally launched before major structural modifications were made in 1936 to improve her stability and operations including curving her funnels down to keep the flight deck clear of smoke. Launched in 1931, Ryujō was small and lightly built in an attempt to exploit a loophole in the Washington Naval Treaty of 1922.

“Ryūjō (‘Prancing Dragon’) was a light aircraft carrier built for the Imperial Japanese Navy (IJN) and commissioned in 1931. Small and lightly built in an attempt to exploit a loophole in the Washington Naval Treaty of 1922, she proved to be top-heavy and only marginally stable and was back in the shipyard for modifications to address those issues within a year of completion.

“Between the time the carrier was laid down in 1929 and launched in 1931, the Navy doubled her aircraft stowage requirement to 48 in order to give her a more capable air group. This necessitated the addition of a second hangar atop the first, raising freeboard to 14.9 meters (48 ft 11 in). Coupled with the ship’s narrow beam, the consequent top-heaviness made her minimally stable in rough seas, despite the fitting of Sperry active stabilizers. This was a common flaw amongst many treaty-circumventing Japanese warships of her generation.

“Ryūjō was docked at the Kure Naval Arsenal for modifications ca. 1936 that strengthened her keel and added ballast and shallow torpedo bulges to further improve her stability. Her funnels were also moved higher up the side of her hull and curved downward to keep the deck clear of smoke.

“During World War II, Ryūjō provided air support for operations in the Philippines, Malaya, and the Dutch East Indies, where her aircraft participated in the Second Battle of the Java Sea. During the Indian Ocean raid in April 1942, the carrier attacked British merchant shipping with her guns and aircraft.

“Ryūjō next participated in the Battle of Dutch Harbor, the opening battle of the Aleutian Islands campaign in June 1942. Two months later, she was sunk by American carrier aircraft in the Battle of the Eastern Solomons on 24 August 1942.”

– Wikipedia

I.J.N. light aircraft carrier Ryujo, 1942. [Source: Japanese Naval Vessels, Division of (U.S.) Naval Intelligence, December 1942.]