Junyo (or Hiyo) class aircraft carriers

The two Junyo class carriers were originally laid down as the passenger liners Kashiwara Maru and Izumo Maru, which were funded by the Imperial Japanese Navy as part of a scheme to provide a number of ships that could easily be converted into aircraft carriers. The two liners were laid down in 1939, but neither of them had been launched when they were requisitioned by the navy in February 1941, and both were completed as carriers.

The Junyo class carriers were the first Japanese aircraft carriers to combine the smoke stacks with the islands, replacing the earlier system in which the smoke stacks were mounted horizontally on the side of the ships. The stacks were sloped outwards at 26 degrees to keep smoke off the flight deck. They were given two hangers served by two elevators, and could carry 48 operational and 5 reserve aircraft.

Front view of Junyo
Front view of Junyo

The Navy was aware that the Junyo class ships were not going to be very fast, and so very little armour was carried, concentrated around the magazines and machinery spaces. They were also given destroyer-type boilers and merchant turbines in an attempt to improve their speed, but without success, and they were 10kts slower than the main fleet carriers.

Displacement (standard)


Displacement (loaded)


Top Speed


Armour – machinery


 - magazines







719ft 6in max


12 5in/40 Dual Purpose guns in double mountings
24 25mm anti aircraft guns

Crew complement


Ships in class


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How to cite this article: Rickard, J (27 November 2008), Junyo or Hiyo class aircraft carriers , http://www.historyofwar.org/articles/weapons_junyo_class.html

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