Warships of the Imperial Japanese Navy, Light Aircraft Carriers: Hosho, Ryūjō, Shōkaku, Junyo, Zuihō, Shōhō, Chitose, Taiyo, Chuyo, Kaiyo, Shin'yo, Akitsu Maru, Nigitsu Maru, Shimane Maru, Yamashio Maru, Kumano Maru

Imperial Japanese Navy, Light Aircraft Carriers: Hosho, Ryūjō, Shōkaku, Junyo, Zuihō, Shōhō, Chitose, Taiyo, Chuyo, Kaiyo, Shin'yo, Akitsu Maru, Nigitsu Maru, Shimane Maru, Yamashio Maru, Kumano Maru

Hosho-class

(Kure Maritime Museum Photo)

Imperial Japanese Navy aircraft carrier Hōshō conducts tests in Tokyo Bay in December 1922.

Hōshō participated in the Battle of Midway in June 1942 in a secondary role. After the battle, the carrier resumed her training role in Japanese home waters for the duration of the conflict and survived the war with only minor damage from air attacks. She was surrendered to the Allies at the end of the war and used to repatriate Japanese troops until she was scrapped in 1946. (Wikipedia)

Light aircraft carrier Hosho (1922–1945), 7,470 tonnes. This was the first purpose-built carrier in the world. It was scrapped in 1946.

Ryujo-class

(Photo from the Archives of the Kure Maritime Museum)

The Imperial Japanese Navy aircraft carrier Ryūjō underway on 6 September 1934.

Ryujo (1931–1942), 8,000 tonnes. Sunk in 1942. Ryūjō (Japanese: 龍驤 "Prancing Dragon") was a light aircraft carrier built for the Imperial Japanese Navy (IJN) during the early 1930s. Small and lightly built in an attempt to exploit a loophole in the Washington Naval Treaty of 1922, she proved to be top-heavy and only marginally stable and was back in the shipyard for modifications to address those issues within a year of completion. With her stability improved, Ryūjō returned to service and was employed in operations during the Second Sino-Japanese War. During World War II, she provided air support for operations in the Philippines, Malaya, and the Dutch East Indies, where her aircraft participated in the Second Battle of the Java Sea. During the Indian Ocean raid in April 1942, the carrier attacked British merchant shipping with her guns and aircraft. Ryūjō next participated in the Battle of Dutch Harbor, the opening battle of the Aleutian Islands campaign, in June 1942. She was sunk by American carrier aircraft in the Battle of the Eastern Solomons on 24 August 1942. (Wikipedia)

Battle of the Eastern Solomons

The American landings on Guadalcanal and Tulagi on 7 August caught the Japanese by surprise. The next day, Ryūjō was transferred to Carrier Division 1 and departed for Truk on 16 August together with the other two carriers of the division, Shōkaku and Zuikaku. Her air group consisted of 24 Zeros and nine B5N2s.[22] Admiral Isoroku Yamamoto, commander-in-chief of the Combined Fleet, ordered Truk to be bypassed and the fleet refueled at sea after an American carrier was spotted near the Solomon Islands on 21 August.[23] At 01:45 on 24 August, Vice Admiral Chūichi Nagumo, commander of the Mobile Force, ordered Ryūjō and the heavy cruiser Tone, escorted by two destroyers, detached to move in advance of the troop convoy bound for Guadalcanal and to attack the Allied air base at Henderson Field if no carriers were spotted. This Detached Force was commanded by Rear Admiral Chūichi Hara in Tone.

Ryūjō launched two small airstrikes, totaling 6 B5Ns and 15 Zeros, beginning at 12:20 once the Diversionary Force was 200 nautical miles (370 km; 230 mi) north of Lunga Point. Four Grumman F4F Wildcat fighters from Marine Fighter Squadron VMF-223 on combat air patrol (CAP) near Henderson Field spotted the incoming Japanese aircraft around 14:20 and alerted the defenders. Ten more Wildcats from VMF-223 and VMF-212 scrambled, as well as 2 United States Army Air Corps Bell P-400s from the 67th Fighter Squadron in response. Nine of the Zeros strafed the airfield while the B5Ns bombed it with 60-kilogram (132 lb) bombs to little effect. The Americans claimed to have shot down 19 aircraft, but only three Zeros and three B5Ns were lost, with another B5N forced to crash-land. Only three Wildcats were shot down in turn.

Around 14:40, the Detached Force was spotted again by several search aircraft from the carrier USS Enterprise; the Japanese ships did not immediately spot the Americans. They launched three Zeros for a combat air patrol at 14:55, three minutes before two of the searching Grumman TBF Avenger torpedo bombers narrowly missed Ryūjō 150 meters (164 yd) astern with four 500-pound (227 kg) bombs. Two more Zeros reinforced the patrol shortly after 15:00, just in time to intercept two more searching Avengers, shooting down one. In the meantime, the carrier USS Saratoga had launched an airstrike against the Detached Force in the early afternoon that consisted of 31 Douglas SBD Dauntlesses and eight Avengers; the long range precluded fighter escort. They found the carrier shortly afterward and attacked. They hit Ryūjō three times with 1,000-pound (454 kg) bombs and one torpedo; the torpedo hit flooded the starboard engine and boiler rooms. No aircraft from either Ryūjō or Saratoga were shot down in the attack.

The bomb hits set the carrier on fire and she took on a list from the flooding caused by the torpedo hit. Ryūjō turned north at 14:08, but her list continued to increase even after the fires were put out. The progressive flooding disabled her machinery and caused her to stop at 14:20. The order to abandon ship was given at 15:15 and the destroyer Amatsukaze moved alongside to rescue the crew. The ships were bombed several times by multiple B-17s without effect before Ryūjō capsized about 17:55 at coordinates 06°10′S 160°50′E with the loss of seven officers and 113 crewmen. Fourteen aircraft that she had dispatched on raids returned shortly after Ryūjō sank and circled over the force until they were forced to ditch. Seven pilots were rescued. (Wikipedia)

Hiyo-class

Light aircraft carriers Hiyo (1942–1944), and Jun'yo (1942–1946), 24,150 tonnes. Converted from an ocean liner in 1939. Hiyō was sunk and Jun'yō was scrapped 1946–1947.

(U.S. Naval History and Heritage Command Photo, 80-G-701429)

IJN Junyo, in Ebisu Bay, Sasebo, 25 September 1945.

Imperial Japanese Navy Jun'yō (隼鷹, "Peregrine Falcon") was a Hiyō-class aircraft carrier. She was laid down as the passenger liner Kashiwara Maru (橿原丸), but was purchased by the IJN in 1941 while still under construction and converted into an aircraft carrier. Completed in May 1942, the ship participated in the Aleutian Islands Campaign the following month and in several battles during the Guadalcanal Campaign later in the year. Her aircraft were used from land bases during several battles in the New Guinea and Solomon Islands Campaigns.

IJN Jun'yō was torpedoed in November 1943 and spent three months under repair. Several bombs damaged her during the Battle of the Philippine Sea in mid-1944, but she was quickly returned to service. Lacking aircraft, she was used as a transport in late 1944 and was torpedoed again in December. Jun'yō was under repair until March 1945, when work was cancelled as uneconomical. She was then effectively hulked for the rest of the war. After the surrender of Japan in September, the Americans also decided that she was not worth the cost to make her serviceable for use as a repatriation ship, and she was broken up in 1946–1947. (Wikipedia)

(U.S. Naval History and Heritage Command Photo, SC 218543)

View of the island of the Japanese aircraft carrier Junyō, seen from the aft flight deck, at Sasebo, Japan, on 19 October 1945. Note the Type 3 radar antenna on the ship's mainmast.

(U.S. Naval History and Heritage Command Photo, USMC 136995)

Japanese aircraft carrier Junyō at Sasebo, Japan, on 26 September 1945. Two HA-201 class submarines are alongside.

(U.S. Naval History and Heritage Command Photo, USMC 136996)

The Japanese aircraft carrier Junyō anchored at Sasebo, Japan, on 26 September 1945.

(AGC-7 Photo, 80-G-352479)

IJN Junyo in Ebisu Bay, Sasebo, 25 September 1945.

(AGC-7, 80-G-352473)

IJN Junyo, in Ebisu Bay, Sasebo, 25 September 1945.

Zuiho-class

Japanese aircraft carrier Zuihō at Yokosuka, Japan, on 28 December 1940.

(IJN Photo)

Japanese aircraft carrier Zuihō at Yokosuka, Japan, on 28 December 1940. The IJN Zuiho (1940–1944), was sunk during the war.

(IJN Photo)

Imperial Japanese Navy aircraft carrier Shōhō, 20 December 1941.

Shoho (1939–1942), 11,443 tonnes. Shōhō was the first Japanese aircraft carrier lost during the Second World War.

Chithose-class

(IJN Photo)

Imperial Japanese Navy aircraft carrier Chitose.

Light aircraft carriers Chitose (1938/1944–1944), and Chiyoda (1938/1944–1944), 11,200 tonnes. Both ships were seaplane tenders before their conversion in 1943. Both ships were sunk in 1944.

Ryuho-class

(IJN Photo)

Imperial Japanese Navy aircraft carrier Ryūhō, 1942.

Light aircraft carrier Ryuho (1934/1942–1945), 16,700 tonnes. Converted from the submarine tender Taigei 1941–1942. Recommissioned as Ryūhō 1942. Scrapped 1946.

IJN Escort Carrier Taiyo-class

IJN escort carriers Taiyo (1941–44), Chuyo (1942–43), Unyo (1942–44), 17,830 tonnes. All were sunk during the war.

(IJN Photo)

IJN escort carrier Taiyo (1941–44)

(IJN Photo)

IJN escort carrier Chuyo (1942–43).

(IJN Photo)

The escort carrier Un'yō steaming astern on Feb 4 or Feb 5 1944 after losing her bow in the stormy seas off Tateyama.

Kaiyo-class

IJN escort carrier Kaiyo (1943–1945), 13,600 tonnes. Converted from ocean liner Argentina Maru. Scrapped in 1946.

Shin'yo-class

(IJN Photo)

IJN escort carrier Shin'yo (1943–1944), 17,500 tonnes.

Akitsu Maru-class

(IJN Photo)

IJN escort carriers Akitsu Maru (1942–1944), and Nigitsu Maru (1942–1944), 11,800 tonnes. Operated by the Imperial Japanese Army. These were the worlds' first Amphibious Assault ships.

Shimane Maru-class

(IJN Photo)

IJN escort carrier Shimane Maru, 28 July 1945 at Shido Bay, Kagawa, Japan. She was completed on 28 February 1945, but was sunk 24 July 1945 by British aircraft at Shido Bay.

8 June 1944: Kobe. Laid down at Kawasaki Heavy Industries’ shipyard as construction number 740, a 10,215-ton Wartime Standard Type 1TL tanker for Ishihara Kisen, K. K. and allotted to the IJN. 19 December 1944: Launched and named SHIMANE MARU.29 February 1944: Completed. Taken over by the IJN for conversion to an escort aircraft carrier. SHIMANE MARU is to be operated under Imperial Army control and carry 12 Yokosuka K5Y1 Type 93 "Willow" intermediate trainers. The plan is for her to provide anti-submarine air cover for convoys going from Southeast Asia to the homeland. She can also be used as a tanker. SHIMANE MARU is fitted with a full length flight deck, small hangar and a single elevator forward, but no catapult. The boiler uptakes are rerouted to run aft to the stern and discharge to starboard via a downward-angled funnel. Her deck is camouflaged with netting and potted plants, the hull also receives camouflage painting. 28 February 1945: Construction is abandoned when almost complete. Escort carrier SHIMANE MARU never becomes operational due to a lack of planes, pilots and fuel. [1]19 March 1945:Vice Admiral (later Admiral) Marc A. Mitscher's (former CO of HORNET, CV-8) Task Force 58 carriers USS ESSEX (CV-9), INTREPID (CV-11), HORNET (CV-12), WASP (CV-18), HANCOCK (CV-19), BENNINGTON (CV-20) and BELLEAU WOOD (CVL-24) make the first carrier attack on the Kure Naval Arsenal. More than 240 aircraft (SB2C Helldivers, F4U "Corsairs" and F6F Hellcats) make the attack on the many ships in the area. Bombs severely damage SHIMANE MARU's stern, flight deck and the area in front of the elevator.1945: Plans are developed to convert damaged SHIMANE MARU to a coal burning freighter. She is probably towed to Shido Bay. There her flight deck is further camouflaged with trees. 24 July 1945: Inland Sea. Attacked in Shido Bay by aircraft from British Task Force 37’s carrier HMS Victorious and heavily damaged by bombs and rockets. She breaks in two and sinks in shallow water at at 34-20N, 134-07E. Only her stern remains above water. Six crewmen are KIA.1945: A mine strikes SHIMANE MARU’s hulk.  1948: Osaka. Scrapped at Naniwa Dock Co. Ltd. (Bob Hackett and Peter Cundall)

(Naval History and Heritage Command Photo)

IJN escort carrier Shimane Maru, c1947-48, showing damage received by bombing at Shido, near Takamatsu. This ship was first intended to be a type 1TL tanker.

(Admiralty Official Collection, Public Domain Photo)

Japanese escort carrier Shimane Maru under attack by Grumman Avenger aircraft from HMS Victorious on 24 July 1945.

IJN escort carrier Shimane Maru (1945), 11,989 tonnes. The Shimane Maru class was a pair of auxiliary escort carriers built for the Imperial Japanese Navy (IJN) in 1945. Four additional conversions were reportedly considered but not carried out. Although both ships were launched, only one was completed, and neither entered active service before being destroyed.

On 24 July 1945, the Fleet Air Arm conducted an attack against the IJN escort carrier  Shimane Maru. The force involved was a portion of the British Pacific Fleet, which was designated Task Force 37 and consisted of the aircraft carriers Formidable, Victorious, Implacable and Indefatigable, the battleship King George V, six cruisers and 15 destroyers. Task Force 37 began operations on 17 and 18 July by launching a series of strikes against the Japanese home islands alongside the American Task Force 38. During these initial strikes, the attacking British aircraft destroyed or damaged several minor Japanese vessels and 48 Japanese aircraft.

Due to persistent bad weather, the next series of Allied attacks did not occur until 24 July. Even then, the weather conditions were far from ideal as low clouds obscured many of the target areas. Despite this, Task Force 38 conducted a series of major air attacks against the important Japanese naval bases at Kure and Kobe. These bases contained the remnants of the once formidable Japanese fleet now immobilised due to a lack of fuel. The American attacks were highly successful as their carrier aircraft sank or heavily damaged a large number of Japanese warships including the battleships Ise, Hyūga and Haruna and the aircraft carriers Amagi and Katsuragi.

Task Force 37 launched a maximum effort against targets in and around the Inland Sea. In all, the British conducted 15 strikes against Japan consisting of 227 offensive sorties out of a total of 416 sorties flown for the day. In the early afternoon one of these strikes, consisting of six Avengers, two Fireflies and two Corsairs from the aircraft carriers Victorious and Implacable, happened upon and attacked what they described as a Kobe-class escort carrier off Shido Bay in the Inland Sea. For the loss of one Firefly, these aircraft succeeded in hitting the Japanese carrier with two 500-pound bombs. In follow-up strikes, Corsairs from Formidable strafed and bombed the stricken carrier, and then a force of Avengers and Seafires from Indefatigable bombed it again claiming two more hits and a near miss. These attacks left the Japanese escort carrier fatally damaged with a broken back and a breached hull. It bottomed in shallow water and remained a derelict wreck until 1948 when it was finally scrapped. Interestingly, the identity of this ship remained in dispute for a number of years. Most early historical accounts identified it as the escort carrier Kaiyo, but more recent analysis shows it was in fact the 11,800-ton auxiliary escort carrier Shimane Maru.

In other attacks during the day, the British destroyed a small freighter (possibly the 873-ton Komyo Maru), at least seven other minor vessels and 15 aircraft. They further damaged numerous other vessels, 31 aircraft and various shore installations and transportation centres. British losses in attaining these successes amounted to just four aircraft in return. On the 25th the British continued their aerial onslaught against Japan, but a deterioration in the weather quickly curtailed offensive operations, and Task Force 37 was only able to launch 155 sorties for the day. Despite this low number, the British still achieved a fair degree of success as their aircraft destroyed two enemy aircraft on the ground with six more damaged, and sank or damaged three freighters, a large cargo ship and several junks and coasters in the Inland Sea. That night the British added to this score when two Hellcats from Formidable intercepted and shot down three out of four Grace torpedo-bombers that were attempting to attack the fleet for no loss to themselves.

Task Force 37 would continue its operations against Japan in the succeeding days. (Forgotten War, the British Empire and Commonwealth’s Epic Struggle Against Imperial Japan, 1941-1945)

Yamashio Maru-class

(IJN Photo)

IJN escort carrier Yamashio Maru (1945–1945)16,119 tonnes.

Kumano Maru-class

(IJN Photo)

IJN escort carrier Kumano Maru (1945–1945), 8,258 tonnes. Operated by Imperial Japanese Army..

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