Japanese aircraft carrier Kaiyo
Encyclopedia
was a escort carrier operated by the Imperial Japanese Navy
(IJN) in World War II
. The ship was originally built as the ocean liner
Argentina Maru. She was purchased by the IJN on 9 December 1942, converted into an escort carrier, and renamed Kaiyo. The ship was primarily used as an aircraft transport, escort carrier and training ship during the war. She was badly damaged by repeated air attacks in July 1945 and was scrapped
in 1946–48.
Argentina Maru was completed in 1939 and rated at . After being rebuilt, the ship had a length of 155 metre overall. She had a beam
of 21.9 metre and a draft of 8.04 metre. She displaced
13600 tonnes (13,385.2 LT) at standard load. As part of her conversion, her original diesel engine
s, which had given her a top speed of 21.5 knots (11.7 m/s), were replaced by a pair of destroyer-type geared steam turbine
sets with a total of 52000 shp, each driving one propeller. Steam was provided by four water-tube boiler
s and Kaiyo now had a maximum speed of 23 knots (12.5 m/s). She carried enough fuel oil
to give her a radius of 7000 nautical miles (12,964 km). Her crew numbered 829 officers and men.
The ship's flight deck
was 72 feet (21.9 m) wide and Kaiyo had a single hangar
, served by two aircraft elevators, mounted on the centerline. She was not built with an island and could operate 24 aircraft. The ship's primary armament consisted of eight 40-caliber
12.7 cm Type 89
anti-aircraft
(AA) guns in twin mounts on sponsons along the sides of the hull. They fired 23.45 kilograms (51.7 lb) projectiles at a rate between 8 and 14 rounds per minute at a muzzle velocity
of 700–725 m/s (2,296.6–2,378.6 ft/s); at 45°, this provided a maximum range of 14800 metres (16,185.5 yd), and a maximum ceiling of 9400 metres (30,839.9 ft). Kaiyo was also initially equipped with eight triple 25 mm Type 96 light AA guns, also in sponsons along the sides of the hull. They fired 0.25 kilogram (0.551155655462194 lb) projectiles at a muzzle velocity
of 900 m/s (2,952.8 ft/s); at 50°, this provided a maximum range of 7500 metres (8,202 yd), and an effective ceiling of 5500 metres (18,044.6 ft). The maximum effective rate of fire was only between 110 and 120 rounds per minute due to the frequent need to change the fifteen-round magazines. In early July 1944, 20 single 25 mm guns were added as were eight depth charge
s. Some sources say that a number of 28-round AA rocket launchers were added in late 1944. Each 12 centimetres (4.7 in) rocket weighed 22.5 kilograms (49.6 lb) and had a maximum velocity of 200 m/s (656.2 ft/s). Their maximum range was 4800 metres (5,249.3 yd). Early warning was provided by a Type 2, Mark 2, Model 1 air search radar
that was installed on the side of the flight deck in November 1943.
in December 1941. The ship began conversion at Nagasaki on 10 December 1942, the day after she was purchased. After the conversion was completed on 23 November 1943, she was renamed Kaiyo. Her initial duties were to transport aircraft to Japanese overseas bases. Her first such task to ferry aircraft for the 23rd Air Flotilla to Singapore
via Manila
in January 1944 as part of Convoy HI-33. On her return journey, the ship transported aircraft of the 551st Air Group to Truk
. On 10 February, en route to Truk from Palau
, the submarine
made a night attack on Kaiyo, but the torpedo
es missed. Kaiyo is briefly refitted between 23 February and 2 March and was assigned to the 1st Surface Escort Division on 17 March. escorted Convoy HI-57 to Singapore via Taiwan
and Indochina
in April. She escorted Convoy HI-58 on the return voyage; one of her aircraft spotted the submarine on the surface behind the convoy. The submarine was damaged by the escorts, but escaped.
In late May, Kaiyo forms part of the escort for Convoy HI-65, together with the escort carrier , bound for Singapore. One of the escorts was torpedoed en route and two of the merchantmen collided while trying to dodge the other torpedoes. The rest of the convoy arrived at Singapore on 12 June. Kaiyo was assigned to fast Convoy HI-66 for the return voyage and reached Japan on 26 June. She was briefly docked at Kure Naval Arsenal
in early July to have more 25 mm AA guns fitted. Together with the escort carrier , Kaiyo was loaded with aircraft bound for the Philippines to be delivered in Convoy HI-69. They departed on 13 July and arrived a week later. The convoy left Manila four days later and reached Japan on 1 August. The ship's machinery broke down as she was preparing to join another convoy on 4 August and she was transferred to Sasebo.
On 25 October, Kaiyo ferried a dozen transport aircraft to Keelung
, Taiwan, and arrived at Kure
on 2 November. The ship was assigned to escort Convoy HI-83 to Singapore via Taiwan and Hainan Island on 25 November and arrived on 13 December. En route, she was assigned to the First Escort Fleet on 10 December. While returning to Japan with Convoy HI-84 later that month, Kaiyo was attacked and missed by the submarine on 31 December. After arriving at Moji
on 13 January 1945, the ship was transferred to Kure and assigned to pilot training in the Inland Sea.
On 19 March 1945, while moored at Kure, Kaiyo was attacked by a American carrier aircraft from Task Force 58. She was hit in the port engine room by a bomb that started fires and caused some flooding. The ship started to list and was moved into shallow water near Etajima
Island lest she sink. On 20 April she was assigned to serve as a target ship for kamikaze
crews. Kaiyo resumed her pilot training duties a month later and hit a mine
on 18 July with only minor damage. Six days later, she struck a mine while attempting to dodge attacks by British-flown Grumman TBF Avenger torpedo bombers. She was hit twice more, possibly by rockets, and was flooding badly. The ship was towed overnight to Beppu Bay
and deliberately grounded the following morning to prevent her from sinking. The ship was attacked again on 28 July by American carrier aircraft that knocked out the ship's power and stopped her pumps. Kaiyo was also hit by 18 rockets and a total of 20 crewmen were killed by the attacks. The damage caused her to ground again with a list to port. The next day she was attacked again by B-25J Mitchell medium bomber
s of the Fifth Air Force
as well as by aircraft from the carrier . The amount of damage inflicted by these attacks, if any, is unknown, but they did cause the ship's captain
to abandon attempts to repair the ship. He ordered that the boilers be flooded with sea water and the machinery coated in oil to better preserve it. Some crewmen were left aboard to man the AA guns.
Low-level air strikes by Okinawa-based B-25J Mitchells of the United States Army Air Forces 38th Bomb Group
on 9 August further damaged the carrier, despite extensive use of camouflage netting and foliage. The following day, the ship's list increased and she was ordered abandoned. Kaiyo was struck from the Navy List on 20 November and scrapped in place from 1 September 1946 and 30 January 1948 by Nissan Salvage.
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...
(IJN) in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The ship was originally built as the ocean liner
Ocean liner
An ocean liner is a ship designed to transport people from one seaport to another along regular long-distance maritime routes according to a schedule. Liners may also carry cargo or mail, and may sometimes be used for other purposes .Cargo vessels running to a schedule are sometimes referred to as...
Argentina Maru. She was purchased by the IJN on 9 December 1942, converted into an escort carrier, and renamed Kaiyo. The ship was primarily used as an aircraft transport, escort carrier and training ship during the war. She was badly damaged by repeated air attacks in July 1945 and was scrapped
Ship breaking
Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for scrap recycling. Most ships have a lifespan of a few decades before there is so much wear that refitting and repair becomes uneconomical. Ship breaking allows materials from the ship, especially...
in 1946–48.
Description
The ship was ordered as the fast luxury passenger liner Argentina Maru by Osaka Shosen Kaisha (OSK) in 1938. In exchange for a subsidy of her building costs by the Navy Ministry, she was designed to be converted to an aircraft carrier.Argentina Maru was completed in 1939 and rated at . After being rebuilt, the ship had a length of 155 metre overall. She had a beam
Beam (nautical)
The beam of a ship is its width at the widest point. Generally speaking, the wider the beam of a ship , the more initial stability it has, at expense of reserve stability in the event of a capsize, where more energy is required to right the vessel from its inverted position...
of 21.9 metre and a draft of 8.04 metre. She displaced
Displacement (ship)
A ship's displacement is its weight at any given time, generally expressed in metric tons or long tons. The term is often used to mean the ship's weight when it is loaded to its maximum capacity. A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load...
13600 tonnes (13,385.2 LT) at standard load. As part of her conversion, her original diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s, which had given her a top speed of 21.5 knots (11.7 m/s), were replaced by a pair of destroyer-type geared steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
sets with a total of 52000 shp, each driving one propeller. Steam was provided by four water-tube boiler
Water-tube boiler
A water tube boiler is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which heats water in the steam-generating tubes...
s and Kaiyo now had a maximum speed of 23 knots (12.5 m/s). She carried enough fuel oil
Fuel oil
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...
to give her a radius of 7000 nautical miles (12,964 km). Her crew numbered 829 officers and men.
The ship's flight deck
Flight deck
The flight deck of an aircraft carrier is the surface from which its aircraft take off and land, essentially a miniature airfield at sea. On smaller naval ships which do not have aviation as a primary mission, the landing area for helicopters and other VTOL aircraft is also referred to as the...
was 72 feet (21.9 m) wide and Kaiyo had a single hangar
Hangar
A hangar is a closed structure to hold aircraft or spacecraft in protective storage. Most hangars are built of metal, but other materials such as wood and concrete are also sometimes used...
, served by two aircraft elevators, mounted on the centerline. She was not built with an island and could operate 24 aircraft. The ship's primary armament consisted of eight 40-caliber
Caliber (artillery)
In artillery, caliber or calibredifference in British English and American English spelling is the internal diameter of a gun barrel, or by extension a relative measure of the length....
12.7 cm Type 89
12.7 cm/40 Type 89 naval gun
The 12.7 cm/40 Type 89 naval gun was a Japanese anti-aircraft gun introduced before World War II. It was the Imperial Japanese Navy's standard heavy AA gun during the war.-External links:*...
anti-aircraft
Anti-aircraft warfare
NATO defines air defence as "all measures designed to nullify or reduce the effectiveness of hostile air action." They include ground and air based weapon systems, associated sensor systems, command and control arrangements and passive measures. It may be to protect naval, ground and air forces...
(AA) guns in twin mounts on sponsons along the sides of the hull. They fired 23.45 kilograms (51.7 lb) projectiles at a rate between 8 and 14 rounds per minute at a muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
of 700–725 m/s (2,296.6–2,378.6 ft/s); at 45°, this provided a maximum range of 14800 metres (16,185.5 yd), and a maximum ceiling of 9400 metres (30,839.9 ft). Kaiyo was also initially equipped with eight triple 25 mm Type 96 light AA guns, also in sponsons along the sides of the hull. They fired 0.25 kilogram (0.551155655462194 lb) projectiles at a muzzle velocity
Muzzle velocity
Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately to in black powder muskets , to more than in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to for tank guns...
of 900 m/s (2,952.8 ft/s); at 50°, this provided a maximum range of 7500 metres (8,202 yd), and an effective ceiling of 5500 metres (18,044.6 ft). The maximum effective rate of fire was only between 110 and 120 rounds per minute due to the frequent need to change the fifteen-round magazines. In early July 1944, 20 single 25 mm guns were added as were eight depth charge
Depth charge
A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...
s. Some sources say that a number of 28-round AA rocket launchers were added in late 1944. Each 12 centimetres (4.7 in) rocket weighed 22.5 kilograms (49.6 lb) and had a maximum velocity of 200 m/s (656.2 ft/s). Their maximum range was 4800 metres (5,249.3 yd). Early warning was provided by a Type 2, Mark 2, Model 1 air search radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
that was installed on the side of the flight deck in November 1943.
Service history
Argentina Maru was initially used for troop transport after the beginning of the Pacific WarPacific War
The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...
in December 1941. The ship began conversion at Nagasaki on 10 December 1942, the day after she was purchased. After the conversion was completed on 23 November 1943, she was renamed Kaiyo. Her initial duties were to transport aircraft to Japanese overseas bases. Her first such task to ferry aircraft for the 23rd Air Flotilla to Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
via Manila
Manila
Manila is the capital of the Philippines. It is one of the sixteen cities forming Metro Manila.Manila is located on the eastern shores of Manila Bay and is bordered by Navotas and Caloocan to the north, Quezon City to the northeast, San Juan and Mandaluyong to the east, Makati on the southeast,...
in January 1944 as part of Convoy HI-33. On her return journey, the ship transported aircraft of the 551st Air Group to Truk
Chuuk
Chuuk — formerly Truk, Ruk, Hogoleu, Torres, Ugulat, and Lugulus — is an island group in the south western part of the Pacific Ocean. It comprises one of the four states of the Federated States of Micronesia , along with Kosrae, Pohnpei, and Yap. Chuuk is the most populous of the FSM's...
. On 10 February, en route to Truk from Palau
Palau
Palau , officially the Republic of Palau , is an island nation in the Pacific Ocean, east of the Philippines and south of Tokyo. In 1978, after three decades as being part of the United Nations trusteeship, Palau chose independence instead of becoming part of the Federated States of Micronesia, a...
, the submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
made a night attack on Kaiyo, but the torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
es missed. Kaiyo is briefly refitted between 23 February and 2 March and was assigned to the 1st Surface Escort Division on 17 March. escorted Convoy HI-57 to Singapore via Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
and Indochina
Indochina
The Indochinese peninsula, is a region in Southeast Asia. It lies roughly southwest of China, and east of India. The name has its origins in the French, Indochine, as a combination of the names of "China" and "India", and was adopted when French colonizers in Vietnam began expanding their territory...
in April. She escorted Convoy HI-58 on the return voyage; one of her aircraft spotted the submarine on the surface behind the convoy. The submarine was damaged by the escorts, but escaped.
In late May, Kaiyo forms part of the escort for Convoy HI-65, together with the escort carrier , bound for Singapore. One of the escorts was torpedoed en route and two of the merchantmen collided while trying to dodge the other torpedoes. The rest of the convoy arrived at Singapore on 12 June. Kaiyo was assigned to fast Convoy HI-66 for the return voyage and reached Japan on 26 June. She was briefly docked at Kure Naval Arsenal
Kure Naval Arsenal
was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy. -History:The Kure Naval District was established at Kure, Hiroshima in 1889, as the second of the naval districts responsible for the defense of the Japanese home islands along with the establishment of the...
in early July to have more 25 mm AA guns fitted. Together with the escort carrier , Kaiyo was loaded with aircraft bound for the Philippines to be delivered in Convoy HI-69. They departed on 13 July and arrived a week later. The convoy left Manila four days later and reached Japan on 1 August. The ship's machinery broke down as she was preparing to join another convoy on 4 August and she was transferred to Sasebo.
On 25 October, Kaiyo ferried a dozen transport aircraft to Keelung
Keelung
Keelung City is a major port city situated in the northeastern part of Taiwan. It borders New Taipei and forms the Taipei–Keelung metropolitan area, along with the Taipei and New Taipei. Nicknamed the Rainy Port for its frequent rain and maritime role, the city is Taiwan's second largest seaport...
, Taiwan, and arrived at Kure
Kure, Hiroshima
is a city in Hiroshima prefecture, Japan.As of October 1, 2010, the city has an estimated population of 240,820 and a population density of 681 persons per km². The total area is 353.74 km².- History :...
on 2 November. The ship was assigned to escort Convoy HI-83 to Singapore via Taiwan and Hainan Island on 25 November and arrived on 13 December. En route, she was assigned to the First Escort Fleet on 10 December. While returning to Japan with Convoy HI-84 later that month, Kaiyo was attacked and missed by the submarine on 31 December. After arriving at Moji
Moji-ku, Kitakyushu
is a ward of Kitakyūshū, Fukuoka Prefecture, Japan. It is the former city of Moji which was one of five cities merged to create Kitakyūshū in 1963. It faces the city of Shimonoseki across the Kanmon Straits between Honshū and Kyūshū....
on 13 January 1945, the ship was transferred to Kure and assigned to pilot training in the Inland Sea.
On 19 March 1945, while moored at Kure, Kaiyo was attacked by a American carrier aircraft from Task Force 58. She was hit in the port engine room by a bomb that started fires and caused some flooding. The ship started to list and was moved into shallow water near Etajima
Etajima
Etajima is an island in Hiroshima Bay located in southwestern Hiroshima Prefecture.From the city of Hiroshima the island is about 7km out at sea. The island is about 6km from the city of Kure. It is connected to Kure by two bridges....
Island lest she sink. On 20 April she was assigned to serve as a target ship for kamikaze
Kamikaze
The were suicide attacks by military aviators from the Empire of Japan against Allied naval vessels in the closing stages of the Pacific campaign of World War II, designed to destroy as many warships as possible....
crews. Kaiyo resumed her pilot training duties a month later and hit a mine
Naval mine
A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...
on 18 July with only minor damage. Six days later, she struck a mine while attempting to dodge attacks by British-flown Grumman TBF Avenger torpedo bombers. She was hit twice more, possibly by rockets, and was flooding badly. The ship was towed overnight to Beppu Bay
Beppu Bay
Beppu Bay is an arm of the western end of the Seto Inland Sea of Japan.Beppu Bay is located on the northeast coast of Kyushu in Ōita Prefecture. The city of Ōita lies on its southern coast and the city of Beppu at its western end....
and deliberately grounded the following morning to prevent her from sinking. The ship was attacked again on 28 July by American carrier aircraft that knocked out the ship's power and stopped her pumps. Kaiyo was also hit by 18 rockets and a total of 20 crewmen were killed by the attacks. The damage caused her to ground again with a list to port. The next day she was attacked again by B-25J Mitchell medium bomber
Medium bomber
A medium bomber is a bomber aircraft designed to operate with medium bombloads over medium distances; the name serves to distinguish them from the larger heavy bombers and smaller light bombers...
s of the Fifth Air Force
Fifth Air Force
The Fifth Air Force is a numbered air force of the United States Air Force Pacific Air Forces . It is headquartered at Yokota Air Base, Japan....
as well as by aircraft from the carrier . The amount of damage inflicted by these attacks, if any, is unknown, but they did cause the ship's captain
Captain (nautical)
A sea captain is a licensed mariner in ultimate command of the vessel. The captain is responsible for its safe and efficient operation, including cargo operations, navigation, crew management and ensuring that the vessel complies with local and international laws, as well as company and flag...
to abandon attempts to repair the ship. He ordered that the boilers be flooded with sea water and the machinery coated in oil to better preserve it. Some crewmen were left aboard to man the AA guns.
Low-level air strikes by Okinawa-based B-25J Mitchells of the United States Army Air Forces 38th Bomb Group
38th Bombardment Group
The 38th Bombardment Group is an inactive unit of the United States Air Force. It was most recently assigned as the operational component of the 38th Bombardment Wing, stationed at Laon-Couvron Air Base, France, where it was inactivated on 8 December 1957.During World War II the 38th Bomb Group...
on 9 August further damaged the carrier, despite extensive use of camouflage netting and foliage. The following day, the ship's list increased and she was ordered abandoned. Kaiyo was struck from the Navy List on 20 November and scrapped in place from 1 September 1946 and 30 January 1948 by Nissan Salvage.