Aircraft Carriers: IJNS Jun'yō

[Brian James]

Occupation forces pictured inspecting Hiyō Class Aircraft Carrier IJNS Occupation forces pictured inspecting Hiyō Class Aircraft Carrier IJNSOccupation forces pictured inspecting Hiyō Class Aircraft Carrier IJNS Jun'yō in 1945.
She was laid down as the passenger liner Kashiwara Maru, but was purchased by the IJN in 1941 while still under construction and converted into an Aircraft Carrier. Completed in May 1942, she 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.
Jun'yō was torpedoed in November 1943 and spent three months under repair. She was damaged by several bombs during the Battle of the Philippine Sea in mid-1944, but 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. in 1945.
She was laid down as the passenger liner Kashiwara Maru, but was purchased by the IJN in 1941 while still under construction and converted into an Aircraft Carrier. Completed in May 1942, she 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.
Jun'yō was torpedoed in November 1943 and spent three months under repair. She was damaged by several bombs during the Battle of the Philippine Sea in mid-1944, but 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. in 1945.
She was laid down as the passenger liner Kashiwara Maru, but was purchased by the IJN in 1941 while still under construction and converted into an Aircraft Carrier. Completed in May 1942, she 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.
Jun'yō was torpedoed in November 1943 and spent three months under repair. She was damaged by several bombs during the Battle of the Philippine Sea in mid-1944, but 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.

[jbryce1437]

Thanks for the photo and interesting info Brian.

Jim

[designeraccd]

The JUNYO and HIYO were probably 2 of the better-given their war records-carriers the IJN had in WW2. While "slow" compared to most fleet carriers, they managed adequate speed with a fair sized air group. Given those items they could be considered superior "stop gap" CVs than the USN SUWANEE class of cves; which were used as "fill ins", too.

Probably their greatest weakness would be lack of protection, as ocean liners really needed none!! Their island/funnel layout was similar to TAIHO and SHINANO, rather than the other IJN converted CVLs and CVEs. DFO

[designeraccd]

Here is a photo of JUNYO's sister the camera shy HIYO launching in 1943. Also, testing of a foam fire suppression system........ DFO

[designeraccd]

It would be interesting to know the design evolution of this pair of conversions. Does anyone have any English data on their design history and builds?
Specs (Wiki):
Type: Aircraft carrier
Displacement: 24,150 metric tons (23,770 long tons) (standard)
Length: 219.32 m (719 ft 7 in) (o/a)
Beam: 26.7 m (87 ft 7 in)
Draft: 8.15 m (26 ft 9 in)
Installed power: 56,250 shp (41,950 kW)
6 Kampon water-tube boilers

Propulsion: 2 shafts
2 geared steam turbine sets

Speed: 25.5 knots (47.2 km/h; 29.3 mph)
Range: 11,700 nmi (21,700 km; 13,500 mi) at 18 knots (33 km/h; 21 mph)
Complement: 1,187–1,224
Sensors and
processing systems: 1 × Type 2, Mark 2, Model 1 air search radar
Armament: 6 × twin 12.7 cm (5.0 in) Type 89 dual-purpose guns
8 × triple 25 mm (1.0 in) Type 96 AA guns

Armor: Belt: 25–50 mm (0.98–1.97 in)
Aircraft carried: 54
DFO

[Brian James]

Carrier Hiyō pictured during a high pressure foam fire drill at Yokosuka Naval Arsenal on October 7th 1943...Both ships of the Class, Hiyō and Jun'yō, were originally laid down as luxury passenger liners before being acquired by the IJN for conversion to Aircraft Carriers in 1941. Jun'yō was the first of the sister ships to be completed in May 1942 and she participated in the invasion of the Aleutian Islands the following month. Both ships participated in several battles during the Guadalcanal Campaign in late 1942. Their aircraft were disembarked several times and used from land bases in a number of battles in the South West Pacific.
Hiyō was torpedoed in June 1943 and Jun'yō in November; both ships spent about three months under repair. They spent most of the time after their repairs training and ferrying aircraft before returning to combat. Hiyō was sunk by a gasoline vapour explosion caused by an American aerial torpedo hit by a Grumman TBF Avenger from USS Belleau Wood..This knocked out the starboard engine room and started fires, but Hiyō was able to continue, albeit at a slower speed. Two hours later, a large explosion occurred when leaking gasoline vapour ignited and it knocked out all power on the ship. The fires raged out of control and Hiyō sank stern first shortly afterwards. Roughly 1,000 men were rescued by her escorting Destroyers, but 247 officers and enlisted men died aboard the Carrier.

[designeraccd]

HIYO launching planes, 1943.Plus damage (note missing funnel) to JUNYO in 1944. Given the "second rate" status of HIYO and JUNYO in IJN, these 2 carriers certainly were well worth their cost given their combat records! DFO

[Brian James]

The hulked Hiyō Class Carrier Jun'yō pictured at Ebisu Bay, Sasebo on October 19th 1945.

[designeraccd]

Here is the JUNYO post war with HA class subs alongside. The stern view isn't often seen in the West.

The IJN got good value out of these two (JUNYO and HIYO) liner conversions, far more than TAIHO or SHINANO!!! DFO

[designeraccd]

Three detail views of JUNYO, 2 while she was being scrapped postwar. The remains/outline of the hanger deck are very visible. DFO