SHIPS-IN-CLASS (2): IJN Zuiho; IJN Shoho
OPERATORS: Imperial Japan
PROPULSION: 4 x Boilers with 2 x Geared steam turbines developing 52,000 horsepower to 2 x Shafts.
Detailing the development and operational history of the IJN Zuiho Converted Light Carrier.
Entry last updated on 1/25/2018.
Authored by Staff Writer. Content ©www.MilitaryFactory.com.
Owing to a shortage of aircraft-carrying warships during World War 2 (1939-1945), Imperial Japanese Navy (IJN) authorities centered on the idea of converting existing ship hulls to that of support carriers. This proved the case with the Tsurigizaki-class high-speed diesel-powered oilers / submarine tenders which were selected for such a conversion process in 1940. The original ships were part of a 1934 initiative calling for additional support vessels to serve the expansion of the IJN fleet. Tsurigizaki was the lead ship of the class and adopted for service in the early part of 1939. Her sister, Takasaki, was not finished and lay in such a state into 1940.
During January of that year, the unfinished hull of Takasaki was finally attended to when it was decided to complete her as a light carrier, given the name of "Zuiho". The diesel powerplant scheme was dropped in favor of a boiler-fed, steam turbine powered system which immediately improved performance. Much of the ship's natural hull structure and lines were kept as-is though, over the top of nearly the entire vessel's length was added a flattop, straight-through flight deck. A hangar area was installed to manage some thirty warplanes and the hangar-to-deck transfer was handled by way of two powered lifts near centerline. A pair of catapults would be used to get these aircraft into the air in short order. To save on weight and construction time, the warship was not completed with any notable amount of armor protection.
Power was from 4 x Boiler units feeding 2 x Geared steam turbines outputting 52,000 horsepower and driving 2 x Shafts astern. Maximum speed was 28 knots and range was out to 7,800 nautical miles.
Dimensions included an overall length of 674.1 feet with a beam of 59.7 feet and a draught of 21.6 feet. Displacement was 11,262 long tons and the crew complement numbered 785 personnel.
Armament was strictly defensive in nature, the warship expected to be defended by accompany ships, warplanes or simply by its inherent speed. 8 x 127mm /40 caliber Type 89 Anti-Aircraft (AA) guns in four twin-gunned emplacements and 8 x 25mm AA guns in four twin-gunned emplacements were installed for airspace denial.
Her sister in the Zuiho-class became "Shoho" and she, too, saw action in the Second World War.
In as little as a year, Zuiho was ready for service, officially commissioned on December 27th, 1940 - this at a time when aircraft carriers were in high demand by the IJN. She joined the Combined Fleet in January of 1941 and her first major action centered on the Philippines before moving on to the East Indies a time later. In June of 1942, she formed the support force accompanying the main fleet in its assault on Midway Island, a disastrous defeat for the IJN in which several prized carriers were lost (4 total). For October of that year, she formed part of the fleet at the Battle of Santa Cruz Islands in which the IJN managed only a tactical victory against the Americans. During this commitment, the warship took a USN bomb directly to her flight deck but survived - though her aircraft recovery function was entirely negated, forcing her return home.
Following repairs, she supported the evacuation of friendlies from the islands during early-1943. June 19th - 20th, 1944 saw her take part in the Battle of the Philippine Sea which led to yet another American victory. Her warplanes did manage to damage USS South Dakota in the fighting. During the Battle of Leyte Gulf (October 23rd - 26th, 1944), IJN Zuiho was heavily damaged by USN warplanes as part of the Battle of Cape Engano after taking two direct hits from aerial bombs (as well as six near-misses). Her crews valiantly attempted to save the vessel, and did to some extent, for she soldiered on for another six hours or so before being hunted down and officially ended by another USN air attack. While hundreds were rescued by accompanying warships, 215 men went down with the ship.
Both ships of the Zuiho-class were lost to enemy action in World War 2 - irreplaceable losses for the IJN going forward into 1945.