Nitta Maru-class cargo liner


The Nitta Maru-class ocean liner was a class of ocean liners of Japan, serving briefly during the late 1930s up to the beginning of World War II, being converted as the Taiyō-class escort carriers of the Imperial Japanese Navy.

Background and description

The class was designed from the start to be converted, featuring military-grade hull and facilities.
These ships were built by Mitsubishi at their Nagasaki shipyard for the shipping lines Nippon Yusen Kaisha and Osaka Shosen Kaisha. Their names where chosen to match the "NYK" abbreviation.
Nitta Maru and Yawata Maru were ordered for NYK and both were completed before the beginning of the Pacific War in December 1941. The ships were intended for service to Europe, but the start of World War II in September 1939 restricted them to the Pacific. Kasuga Maru had been ordered by OSK and was fitting out when she was acquired by the IJN in 1940 and towed to Sasebo Naval Arsenal on 1 May 1941 to finish her conversion into an escort carrier. She was the first ship to be completed as her sister ships were not converted until 1942.
The Nitta Maru-class ships were cargo liners that had a length of, a beam of and a depth of hold of. They had a net tonnage of 9,397 and a cargo capacity of 11,800 tons. They had accommodations for 285 passengers. The ships were powered by two sets of geared steam turbines made by the shipbuilder, each driving one propeller shaft, using steam produced by four water-tube boilers. The turbines were rated at a total of that gave them an average speed of and a maximum speed of.

Escort carrier conversion

The conversion of the Taiyō-class ships, as the former liners were now known, was fairly austere and they were flush-decked escort carriers that displaced at standard load and at normal load. The ships had an overall length of, a beam of and a draught of. As carriers they had a speed of. The uptakes for the boilers were trunked together into a downward-curving funnel on the starboard side of the hull amidships. The ships carried of fuel oil that gave them a range of at a speed of. Taiyōs crew numbered 747 officers and ratings while her sisters had 850 officers and crewmen.
The flight deck was long and wide. The ships had a single hangar, approximately long, served by two centreline aircraft lifts, each. Taiyō could accommodate a total of 27 aircraft, including four spares, and her sisters had a capacity of 30 aircraft. Although larger, faster and having a larger aircraft-carrying capacity than their western counterparts, these ships were unsuited to a traditional carrier role as they lacked arresting gear.