Specifications following reconstruction
Displacement: 41,300 tons full load
Dimensions: 821.5 x 102.5 x 28.5 feet/250.4 x 31.25 x 8.7 meters
Extreme Dimensions: 855 x 102.5 x 28.5 feet/260.6 x 31.25 x 8.7 meters
Propulsion: Steam turbines, 19 boilers, 4 shafts, 133,000 shp, 31.2 knots
Armor: 6 inch belt, 3 inch armored deck
Armament: 6 single 8/50 SP, 6 dual 4.7/45 DP, 28 25 mm AA
Aircraft: 72 (91 maximum)
Concept/Program: A pair of 47,000 ton battlecruisers (fast battleships) cancelled under the Washington Treaty and reordered as aircraft carriers, equivalent to USS Lexington & USS Saratoga and HMS Glorious & HMS Courageous. One of the two ships was wrecked by an earthquake; the other was compeleted as Japan's first large carrier, and saw extensive service.
Design/Conversion: Hull essentially unchanged, except armor was reduced. Completely reworked from the main deck up, with dual-level hangar. Had short flying-off decks at the bow, opening directly from the hangars, in addition to the main flight deck. Completed without an island. She mounted a cruiser's gun armament, partially in turrets and partially in casemates. The boilers exhausted through a starboard-side funnel, which was angled downward. The short flying-off decks were nearly useless.
Modifications: A small island was installed on the starboard side prior to reconstruction.
Modernization: Underwent a major reconstruction to remove the forward flying decks and modernize the ship. The forward flying decks were eliminated, the hangars extended forward, and the main flight deck lengthened, widened and strengthened. A port-side island was installed; the small starboard island was removed. The gun armament was re-arranged and improved. Aircraft arrangements were improved and there were general updates throughout.
Operational: Generally operated with semi-sister Kaga. Saw extensive service as one of the primary Japanese carriers prior to and during WWII.
Departure from Service/Disposal: Lost at Midway.
Operated in trials and developmental service during the early years of Japanese naval aviation. Was fitted with a small starboard-side island for trials purposes.
Reconstructed at Sasebo Navy Yard 10/1935 to 8/1938. Participated in the Sino-Japanese war, Pearl Harbor raid, Indian Ocean raids in 1942. Bombed by US aircraft at Midway 4 June 1942; munitions and fuel exploded on the flight deck and hangar deck, leading to uncontrollable fires; ship was scuttled 5 June 1942.
Specifications following reconstruction
Displacement: 42,541 tons full load
Dimensions: 788.5 x 106.5 x 31 feet/240.3 x 32.5 x 9.5 meters
Extreme Dimensions: 812.5 x 106.5 x 31 feet/247.6 x 32.5 x 9.5 meters
Propulsion: Steam turbines, 8 boilers, 4 shafts, 127,400 shp, 28.34 knots
Crew: 2016
Armor: 11 inch belt
Armament: 10 single 8/50 SP, 8 dual 5/40 DP, 22 25 mm AA
Aircraft: 81 (90 maximum)
Concept/Program: A fast battleship cancelled under the Washington Treaty and reordered as a carrier to replace Amagi. She was Japan's second large carrier became a semi-sister to Akagi.
Design/Conversion: Hull essentially unchanged. Completely reworked from the main deck up, with dual-level hangar. Had short flying-off decks at the bow, opening directly from the hangars, in addition to the main flight deck. Completed without an island. She mounted a cruiser's gun armament, partially in turrets and partially in casemates. The short flying-off decks were nearly useless. Boiler exhausts were run aft to the stern beside the hangar deck. Limited by relatively slow speed.
Modifications: A small island was installed on the starboard side prior to reconstruction.
Modernization: Underwent a major reconstruction to remove the forward flying decks, improve speed, and modernize the ship. The forward flying decks were eliminated, the hangars extended forward, and the main flight deck lengthened, widened and strengthened. A starboard-side island was installed. The gun armament was re-arranged and improved. She was completely re-engined; boiler exhuasts replaced by a downward-angled starboard-side funnel. Aircraft arrangements were improved and there were general updates throughout.
Operational: Generally operated with semi-sister Akagi. Saw extensive service as one of the primary Japanese carriers prior to and during WWII.
Departure from Service/Disposal: Lost at Midway.
Operated in trials and developmental service during the early years of Japanese naval aviation. Was fitted with a small starboard-side island for trials purposes.
Reconstructed at Sasebo Navy Yard 1934-1935. Participated in the Sino-Japanese war, Pearl Harbor raid, Indian Ocean raids in 1942. Bombed by US aircraft at Midway 4 June 1942; munitions and fuel exploded on the flight deck and hangar deck, leading to uncontrollable fires; blew up and sank when the gasoline tanks exploded.
Concept/Program: First large purpose-built Japanese aircraft carrier; design was the basis for all later fleet carrier construction. The program originated as an "flight deck cruiser" designed to get around treaty restrictions, but the design became a full fleet carrier when the treaties were abrogated. Hiryu was intended as a sistership but was completed to a modified design.
Design: A completely new design, and relatively lightly built. Dual hangars with full-length flight deck and starboard-side island. Cruiser-type machinery used for high speed.
Operational: Generally operated with semi-sister Hiryu as part of IJN's second carrier division.
Departure from Service/Disposal: Sunk at Midway.
Participated in the Sino-Japanese war; air group was sent ashore to support the Army in China in 1938, 1940, and early 1941. Participated in the Pearl Harbor raid, and Indian Ocean raids in 1942.
Bombed by US aircraft at Midway 4 June 1942; munitions and fuel exploded on the flight deck and hangar deck, leading to uncontrollable fires; blew up and sank when the gasoline tanks exploded.
Concept/Program: An improved version of Soryu, often considered to be her sistership.
Design: Soryu design with strengthened hull, raised forecastle, improved armor, a port-side island, and other minor changes.
Operational: Generally operated with semi-sister Soryu as part of IJN's second carrier division.
Departure from Service/Disposal: Sunk at Midway.
Participated in the Sino-Japanese war, Pearl Harbor raid, Indian Ocean raids in 1942. Bombed by US aircraft at Midway 4 June 1942; munitions and fuel exploded on the flight deck and hangar deck, leading to uncontrollable fires; ship was scuttled 5 June 1942.
Concept/Program: The third pair of fleet carriers, and the last big carriers completed before WWII. They were an improved and enlarged Soryu.
Design: In general similar to the Soryu design, but more significantly larger, more heavily built, better armed and armored. They were the best Japanese carriers built. The original design had included a port-side island on one ship (as in the previous carrier pairs), but completed with starboard-side islands.
Modifications: During WWII they carried 96 25 mm AA and 6 28-barrel AA rocket launchers. Zuikakulater carried additional AA armament and had other modifications.
Operational: Usually operated together, until Shokaku was lost.
Departure from Service/Disposal: Both lost in WWII.
Participated in the Pearl Harbor raid. Bombed with serious damage at Coral Sea 8 May 1942; barely survived the return to Japan for repairs. Damaged at Eastern Solomons 8/1942 and seriously damaged at Santa Cruz 10/1942; six bomb hits.
Torpedoed and sunk by submarine Cavalla during the Battle of the Philippine Sea, 19 June 1944.
Participated in the Pearl Harbor raid and Coral Sea; seriously damaged at the Battle of the Philippine Sea. Sunk by seven bombs and seven torpedoes during Leyte Gulf, 25 October 1944, while serving as a decoy.
Concept/Program: Large liners built under the "Shadow Program" and intended for easy conversion to carriers. They were an intermediate type between heavy and light fleet carriers: as large as the heavies, but too slow for effective fleet operations. These vessels were classed as auxiliaries until 31 July 1942, when they were reclassified as warships.
Design/Conversion: Taken over prior to completion. Reworked from the main deck up with dual hangars (restricted in height to reduce topweight), full length flight deck, large island, bulged hull, etc. Sea speed was 22-23 knots and the low hangar clearances were a serious hindrance.
Modifications: Both received an additional 26 25 mm AA in 1943; Junyo carried up to 76 25 mm by 1944.
Operational: Both saw varied service through 1944.
Departure from Service/Disposal: Hiyo sunk 1944; Junyo rendered inoperable in 1944.
Took part in the Aleutian campaign, battle of Santa Cruz, off Guadalcanal, seriously damaged in the Philippine Sea 6/1944. Torpedoed off Nagasaki 12/1944 with serious damage; not fully repaired, laid up for the remainder of the war. Hulk scrapped 1947.
Suffered unreliable engines early in her service; the air group was split up and operated ashore for a period; rejoined the ship late 1942. Operated off Guadalcanal several times. Damaged by a submarine torpedo 7 June 1943.
Torpedoed and sunk during the Battle of the Philippine Sea, 20 June 1944.
Concept/Program: A large, heavily armored carrier design embodying many wartime improvements, but too late to see effective service. These ships were meant to serve as the core of fleet battlegroups. Two ships of a slightly improved design were ordered but cancelled in favor of a 5-ship program of improved ships; this in turn was cancelled by wartime events.
Design: Essentially a Shokaku design with an armored flight deck, revised armament, enclosed bows, much larger island, and other improvements.
Departure from Service/Disposal: Sunk soon after completion of shakedown.
Hit by one submarine torpedo and blew up due to spreading gasoline vapors, 19 June 1944.
Concept/Program: A final class of fast fleet carriers, but intended for strikes against US convoys, not fleet actions. They were intended to operate with large heavy cruiser screening forces.
Design: Generally similar to Hiryu but with starboard-side islands. Lightly built and intended for mass production. They used cruiser machinery, but two unit received destroyer machinery to speed prodution.
Departure from Service/Disposal: None ever deployed operationally. Many were incomplete at the end of the war; the survivors and hulks were scrapped postwar.
The ship was operational but never embarked aircraft. Torpedoed and sunk by submarines Redfish off Shanghai 19 December 1944.
Never deployed. Bombed at Kure by US aircraft 24 June 1945, grounded to prevent sinking, capsized 28 June 1945. Hulk scrapped in 1947.
Never deployed. Damaged in late-war raids on Kure. Used as repatriation ship postwar. Scrapped at Osaka in 1947.
Concept/Program: A large battleship hull of the Yamato class taken over for conversion to a carrier. The ship was intended to operate as a support, supply and repair base for the fast fleet carriers. She would have carried a mid-size air group of her own, plus spare aircraft, parts and supplies for the fleet carriers, enabling those ships to resupply without returning to Japan. She was the largest carrier prior to 1960.
Design/Conversion: Single-level hangar built above the main deck, armored flight deck, large island. The battleship hull was unchanged.
Departure from Service/Disposal: Never became operational; sunk prior to fitting out. When lost she had no functional damage control facilities.
Torpedoed and sunk by Archerfish 29 Nov 1944 while moving to Kure for fitting out.
Concept/Program: Japan's first aircraft carrier. Often considered the first ship built from the keel up as a carrier, but was initially laid down as a tanker and redesigned during construction. Officially known as an aircraft depot ship. She was extensively used for experimental, trials and development work.
Design: Designed with considerable British assistance; relatively conventional carrier design, but quite small. Had three folding funnels and a small starboard-side island.
Modifications: The island was removed in 1923 due to interference with smoke discharge; her funnels were fixed in the upright position in 1934. During WWII she was refitted with heavier AA batteries.
Operational: Served in experimental, trials and development roles up to 1933, then as training carrier. Returned to combat service during WWII but saw no noteworthy action.
Departure from Service/Disposal: One of the Japanese carriers to survive the war; scrapped postwar.
Island removed 1923. Served as experimental, trials and development ship until 1933, then as a training carrier. 3.1 inch guns replaced by 13 mm guns 2/1936. In reserve for repair and modification, 12/1937 to 11/1940.
Aircraft capacity reduced to 11 by 1940. Returned to first-line duty in WWII; sailed with the main strike force at Midway but saw no combat. 5.5 inch guns removed 1944, 30 25 mm added. By 1945 her armament was reduced to 6 25 mm AA. Slightly damaged in air raid 28 July 1945. Used as repatriation ship postwar, taken out of service 16 August 1946, scrapped at Osaka starting 30 April 1947.
Concept/Program: A small carrier designed to fill the remaining tonnage allowed by treaty. The design attempted too much on the displacement, and the ship was not a success. However, she did set the pattern for a series of light carriers which followed.
Design: Built on a cruiser-type hull. Originally planned with a single-level hangar, but changed to dual hangars during construction. She was lightly armored, unstable and overloaded as completed.
Modifications: Immediately following commissioning she was reconstructed with a strengthened hull, bulges, and a reduction of the heavy AA armament; following modifications she was 13,650 tons full load, 575.5 x 68 x 23 feet/175.4 x 20.7 x 7 meters, 924 crew, armed with 4 dual 5/40 DP, 4 25 mm, 24 13 mm; 37 aircraft.
The forecastle had to be raised to overcome wetness induced by the modifications. During WWII additional AA guns were fitted.
Operational: Saw varied service early in WWII, but was soon sunk.
Departure from Service/Disposal: Lost during the Guadalcanal battles.
Reconstructed at Yokosuka Yard 1934-1936, and soon returned for additional modifications. Operated around the Philippines, East Indies and Aleutians early in WWII; 6 triple 25 mm AA added early 1942. Sunk by bombs and torpedoes 24 August 1942, off Guadalcanal.
Concept/Program: Originally built as fleet seaplane carriers as part of the "Shadow Program". They were meant to be easily convertible to fleet oilers, submarine tenders, or light carriers. Following the carrier losses early in WWII both underwent reconstruction as carriers, but had fairly short and unproductive careers.
Design/Conversion: These ships had been modified in 1941 to carry and launch 12 midget submarines, a capability which they apparently retained post-conversion. During the conversion all superstructure was demolished down to the main deck, a hangar and flight deck were built, AA armament completely reworked, hulls bulged, and exhausts routed into downward-angled discharges. The ships did not have islands.
Modifications: Both received additional 6 triple 25 mm AA prior to loss.
Operational: Japan was desparately short of aircraft and pilots by the time these ships entered service as carriers, so they saw little operational service.
Departure from Service/Disposal: Both lost during Leyte Gulf, while acting as decoys.
Bombed and sunk during Leyte Gulf, 25 October 1944, while serving as a decoy.
Disabled by aircraft, sunk by cruiser and destroyer gunfire during Leyte Gulf, 25 October 1944, while serving as a decoy.
Concept/Program: Originally built as submarine tenders as part of the "Shadow Program". They were meant to be easily convertible to fleet oilers or light carriers. In 1940-41 both underwent reconstruction as carriers.
Design/Conversion: During the conversion most superstructure was reworked, a hangar and flight deck were built, AA armament completely reworked, hulls bulged, all new engines fitted, and exhausts routed into downward-angled discharges. The ships did not have islands. The new hangar was an expansion of the small seaplane hangar the ships carried in their original role.
Modifications: Zuiho received 6 triple 25 mm AA in 1943, 20 more 25 mm in 1944, along with 6 8-barrel AA rocket launchers; her flight deck was extended forward.
Operational: Zuiho participated in many wartime campaigns.
Departure from Service/Disposal: Shoho sunk at Coral Sea; Zuiho at Leyte.
Covered East Indies invasion, damaged at Santa Cruz 25 October 1942, operated off Guadalcanal 12/1942 and in the Marianas 6/1943. Ferried aircraft to Truk during late 1942 and early 1943.
Sunk by multiple bombs and torpedoes during Leyte Gulf, 25 October 1944, while serving as a decoy.
Ferried aircraft to Truk early in her career. Sunk by US aircraft in the Coral Sea 7 May 1942.
Concept/Program: Another converted submarine tender, generally similar to Zuiho.
Design/Conversion: As a submarine tender she had been lightly and rapidly built, was structurally deficient, and required extensive modifications 1936-37. Conversion to carrier was generally similar to Zuiho. During the conversion most superstructure was reworked, a hangar and flight deck were built, AA armament completely reworked, hulls bulged, all new engines fitted, and exhausts routed into downward-angled discharges. The ship did not have an island. The new turbine machinery was needed for speed, but delayed the conversion and caused serious problems in service. This ship was not a success.
Modifications: Light AA increased to 54 25 mm and 6 13.2 mm in 1943; to 61 25 mm, 21 13.3 mm and 6 28-barrel AA rocket launchers in 1944. Her flight deck was extended forward in 1944.
Operational: Was damaged several times and saw little operational service; mostly used for training but made one combat deployment in 1944.
Departure from Service/Disposal: Survived the war, but seriously damaged and scrapped postwar.
Damaged by US B-25 raid during conversion. Torpedoed 12/1942 while ferrying aircraft to Truk. Had consistent machinery problems. Operated as a training carrier for most of her career, but deployed operationally in 1943, temporarily replacing Hiyo.
Severely damaged at Kure by US aircraft 17 March 1945. Hulk scrapped 1946.
Concept/Program: A heavy cruiser hull taken over for completion as a carrier as an emergency measure following the carrier disasters of 1942-43. Construction was delayed and eventually stopped by wartime hardships, and the ship never saw service.
Design/Conversion: Originally a heavy cruiser, apparently an improved Mogami type. Conversion was typical of the light carriers, but with a single hangar, one half the boilers removed for fuel storage, and a relatively large island.
Departure from Service/Disposal: Hulk scrapped postwar.
Concept/Program: The first Japanese escort carriers, built from small passenger liners and intended for supporting duties such as training and aircraft transport. These vessels were classed as auxiliaries until 31 August 1942, when they were reclassified as warships.
Design/Conversion: Simple conversion. Small hangar and relatively short flight deck added, no island, catapult or arresting gear.
Variations: The AA armament varied.
Modifications: The AA armament was augmented during WWII.
Operational: Served almost exclusively in transport and training roles.
Departure from Service/Disposal: All were sunk by submarines before the end of 1944.
Used for training and transport but made one combat deployment. Final armament was 2 dual 5/40, 64 25 mm, 10 13.2 mm. Sunk by submarine Rasher off the Philippines, 18 Aug 1944.
Used solely for transport and training. Final armament was 2 dual 5/40, 64 25 mm, 10 13.2 mm. Sunk by submarine Barb near Hong Kong, 15 Sept 1944.
Used solely for transport and training. Final armament was 4 dual 5/40 DP, 22 25 mm AA, 5 13.2 mm AA. Torpedoed and sunk by submarine Sailfish near the Home Islands, 4 Dec 1943.
Concept/Program: Another escort carrier conversion from a small liner. Originally taken over as a troop transport but converted to a carrier in view of the critical need for carriers.
Design/Conversion: Simple conversion, similar to other escort carriers. Small hangar and relatively short flight deck added, no island, catapult or arresting gear. Original diesels replaced by destroyer machinery. Second ship was sunk prior to conversion.
Modifications: By mid-1944 was fitted with an additional 20 25 mm AA and some AA rocket launchers.
Operational: Used as transport and training carrier.
Departure from Service/Disposal: Wrecked by British aircraft and scrapped postwar.
Used as transport through 1944, then training carrier. Sunk by US aircraft 24 July 1945. Hulk scrapped postwar.
Concept/Program: Another escort carrier converted from a small liner. This was an ex-German liner acquired early in the war; the Germans also had planned a carrier conversion for this ship and her sister.
Design/Conversion: Simple conversion, similar to other escort carriers. Small hangar and relatively short flight deck added, no island, catapult or arresting gear. Hull was bulged to counteract instability caused by higher placement of hangar and flight deck, in turn due to hull shear.
Modifications: The AA battery was up to 42 25 mm early in 1944 and up to 50 25 mm by mid-1944. Her boilers were experimental high-pressure units and caused constant problems, so she was reboilered at some point in her career.
Operational: Used solely for training.
Departure from Service/Disposal: Like many other escort carriers, sunk by submarines.
Used solely for training. Sunk by submarine Spadefish in the Yellow Sea, 17 Nov 1944.
Concept/Program: Another small passenger liner planned for conversion, but sunk before this could be carried out.
Design/Conversion: Would have been similar to the other escort carriers. Some sources indicate her hangar would have been open-sided.
Concept/Program: Merchant ships acquired, converted and operated by the Army as minimal aircraft carriers to support amphibious operations in the Western Pacific and East Indies. They were intended to assist in the defense of amphibious convoys, transport aircraft to landing areas, and fly aircraft off for defensive and assault-support roles. They could fly off conventional aircraft but not land them, however, they did operated autogyros, which could land aboard. Little is known about these ships service histories.
Design/Conversion: Converted passenger liners, taken over before completion. An extremely simple conversion. A lightweight, relatively short flight deck was built above the hull, on top of the superstructure. There was no hangar, but aircraft could be stored below the flight deck on the original main deck. The funnels and bridge were relocated to the starboard side, and several small cranes were fitted. There was no arresting gear. They retained their original cargo capabilities.
Departure from Service/Disposal: Both sunk by submarines in 1944.
Concept/Program: Another Army conversion, generally similar to the previous class in role and design.
Design/Conversion: Generally similar to Akitsu Maru. It is not known whether a hangar was installed; there was a funnel in the center of the flight deck, and apparently no bridge.
Departure from Service/Disposal: Never employed operationally, and reconverted postwar.
Never became operational. Served as a repatriation ship postwar, then reconverted as a merchant ship. Possibly scrapped at Kobe 11/1947 to 9/1948.
Concept/Program: A continuation of the Army assault/escort carrier concept, these were tankers converted by the Army to provide minimal air cover for troop convoys.
Design/Conversion: Minimal conversion: 2/3 length flight deck fitted, but no hangar, catapults, etc. The boiler uptakes were run aft and discharged at the sides of the flight deck. No island.
Operational: Would have been operated under Army control, with Army aircraft. Neither became an operational ship.
Concept/Program: Tankers converted by the Army to provide minimal air cover for troop convoys. Four additional conversions were reportedly considered but not proceeded with. These were extremely spartan carriers.
Design/Conversion: Minimal conversion: full length flight deck fitted, small hangar, single elevator, but no catapults. No island. The boiler uptakes were run aft to the stern, discharging to starboard.
Operational: Would have been operated under Army control, with Army aircraft. Neither became an operational ship.
