Ryujo (aircraft carrier)

The Ryujo was originally designed as an aircraft carrier that would be too small to count towards the total tonnage of aircraft carriers allowed to Japan under the terms of the Washington Naval Treaty. This would have made it an 8,000 ton ship capable of carrying 24 aircraft, but the Imperial Japanese Navy decided that this was too small an air group to be effective. The design was modified to include a second hanger, which allowed her to carry 48 aircraft, 37 of which could be operational.

This change was made without increasing the dimensions of the ship, and as a result she was too lightly built and unstable. After a year in service she had to be modified to improve her stability – two of her main guns were removed, and she was given larger bulges and more ballast. This still didn’t solve all of the problems, and in 1936 an extra foredeck was added. Her armament was also repeatedly modified, and by the start of the Pacific War she was armed with 22 25mm antiaircraft guns.

Carrier Ryujo from the left
Carrier Ryujo from the left

In December 1941 the Ryujo was used to cover the invasion of the Philippines, and in February 1942 the invasion of Java. In April 1942 the Japanese launched a major carrier raid into the Indian Ocean, using five carriers for the main attack on Ceylon and the British Eastern Fleet. A second force, commanded by Vice-Admiral Ozawa, and including the Ryujo as its sole carrier, was sent on a raid into the Bay of Bengal. In three days this force sank 23 ships of 112,312 tons, while aircraft from the Ryujo attacked Vizagapatan and Cocanada, on the east coast of India, causing an invasion scare that lasted long after the Japanese fleet had returned to the Pacific.

During the Midway campaign of June 1942 the Ryujo was one of two carriers sent on the diversionary raid on Dutch Harbor in the Aleutian Islands. 

The Ryujo was sacrificed at the battle of the Eastern Solomons of August 1942. A powerful force which included the fleet carriers Shokaku and Zuikaku was sent to support an attempt to get reinforcements onto Guadalcanal. The Ryujo was sent ahead of the main force, partly to allow her aircraft to attack the US Marines on Guadalcanal and partly to draw the Americans into a battle on Japanese terms.

The plan was partially successful. On the morning of 24 August American scout planes found the Ryujo, and Admiral Fletcher sent 67 aircraft from his two carriers (the Enterprise and the Saratoga) to attack the small Japanese carrier. Although American scouts then discovered the two main Japanese carriers it was too late to alter the target of the attack and most of the American aircraft hit the Ryujo. She was struck by four bombs and a torpedo, and sank.

Ryujo as newly completed, 1933
Ryujo as newly completed, 1933

The sacrifice of the Ryujo allowed the two Japanese fleet carriers to launch an attack on the Enterprise and the Saratoga, hitting the Enterprise with three bombs, although without sinking her. The operation failed to achieve its main objective – the ships carrying the reinforcements to Guadalcanal were forced back by Marine dive-bombers based at Henderson Field.

Statistics after 1936

Displacement (standard)


Displacement (loaded)


Top Speed



10,000 nautical miles


37 operational
48 maximum


590ft 4in max


8 5in/40 Dual Purpose guns in four double mountings
4 25mm AA guns (22 from 1942)
24 13mm AA guns

Crew complement



2 April 1931


9 May 1933

Sunk at Eastern Solomons

24 August 1942

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How to cite this article: Rickard, J (27 November 2008), Ryujo (aircraft carrier) , http://www.historyofwar.org/articles/weapons_ryujo.html

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