# Unryū-class aircraft carrier

The Unryū-class aircraft carriers (雲龍型航空母艦, Unryū-gata Kōkūbokan) were World War II Japanese aircraft carriers. Sixteen ships of the class were planned under the Maru Kyū Programme (Ship #302 in 1941) and the Kai-Maru 5 Programme (#5001–5015 in 1942). However, only three of the Unryū-class carriers were completed.

## Design

In the lead-up to the Pacific War the Imperial Japanese Navy (IJN) attempted to build a large number of fleet carriers. For them to be built quickly, the design for these ships was based on the aircraft carrier Hiryū rather than the newer and more sophisticated Taihō or the Shōkaku class.
The Unryū-class aircraft carrier design was very similar to that of Hiryū. The ships were lightly built, and the main difference from Hiryū was that the carriers' island was placed on the starboard side of the ships. The carriers were capable of carrying 63 aircraft in two hangars, and were fitted with two elevators. The Unryū class carried a smaller quantity of aviation fuel than Hiryū with fuel tanks protected by concrete. The ships were fitted with the same propulsion system used in the aircraft carrier Sōryū to reach 34 knots (63 km/h), though Katsuragi was instead fitted with two turbines of the same type used in destroyers and had a maximum speed of 32 knots (59 km/h). The carriers also had a similar armament as Hiryū and were equipped with two Type 21 radars and two Type 13 radars.

## Construction

The first three Unryū-class aircraft carriers were laid down in 1942 and construction of a further three began the next year. Eventually, only three (Unryū, Amagi, and Katsuragi) were completed and construction of the other three carriers (Kasagi, Aso and Ikoma) was abandoned in 1945.

## Ships in classes
### Unryū class

Project number was G16. General production model of the Unryū class. 3 carriers were completed. The IJN unofficial designation for Unryū and Amagi were Modified Hiryū class (改飛龍型, Kai Hiryū-gata), Ship Number 5002–5006 were Modified Unryū class (改雲龍型, Kai Unryū-gata) also.
* Unryū (built by Yokosuka Naval Arsenal used the same boilers and turbines as the heavy cruiser Suzuya.
* Amagi and Kasagi (built by Mitsubishi, Nagasaki Shipyard) were equipped with surplus stock of the Ibuki-class cruiser machinery.
* Katsuragi and Aso (built by Kure Naval Arsenal) were equipped with two sets of the Kagerō-class destroyer machinery, because Japanese industrial power became scarce. Dead space was replaced by fuel tanks.
* Ship Number 5002 and 5005 (built by Yokosuka Naval Arsenal) were to have been built simultaneously using Shinano's dock. However, they were cancelled because Shinano was continued.
Construction data :
| Ship # | Ship | Builder | Laid down | Launched | Completed | Fate |
| 302 | Unryū (雲龍) | Yokosuka Naval Arsenal | 1 August 1942 | 25 September 1943 | 6 August 1944 | Sunk by USS Redfish, 19 December 1944. |
| 5001 | Amagi (天城) | Mitsubishi-Nagasaki Shipyard | 1 October 1942 | 15 October 1943 | 10 August 1944 | Sunk by air raid, 28 July 1945. Salvaged and scrapped between 5 December 1946 – 12 November 1947. |
| 5002 | | Yokosuka Naval Arsenal | | | | Cancelled, 1943; materials were used for Shinano. |
| 5003 | Katsuragi (葛城) | Kure Naval Arsenal | 8 December 1942 | 19 January 1944 | 15 October 1944 | Scrapped between 22 December 1946 – 30 November 1947. |
| 5004 | Kasagi (笠置) | Mitsubishi-Nagasaki Shipyard | 14 April 1943 | 19 October 1944 | (June 1945) | 84% complete. Construction stopped on 1 April 1945. Scrapped between 1 September 1946 – 31 December 1947. |
| 5005 | | Yokosuka Naval Arsenal | | | | Cancelled, 1943; materials were used for Shinano. |
| 5006 | Aso (阿蘇) | Kure Naval Arsenal | 8 June 1943 | 1 November 1944 | (September 1945) | 60% complete. Construction stopped on 9 November 1944. Damaged by air raids in July 1945. Scuttled, July 1945. Salvaged and scrapped between 21 December 1946 – 26 April 1947. |

### Ikoma class

The Ikoma subclass was a simplified and sped-up construction model of the Unryū class. They were equipped with shift-arrangement machinery (four sets of parallel boilers and one turbine). Therefore, their funnels were intended to be spaced out. The IJN unofficial designation for this class was Modified Ship Number 302-class (改第302号艦型, Kai Dai 302-Gōkan-gata).
Construction data :
| Ship # | Ship | Builder | Laid down | Launched | Completed | Fate |
| 5007 | Ikoma (生駒) | Kawasaki-Kobe Shipyard | 5 July 1943 | 17 November 1944 | (October 1945) | 60% complete. Construction stopped, 9 November 1944. Scrapped 4 July 1946 – 10 March 1947. |
| 5008 | Kurama (鞍馬) or Kaimon (開聞) | Mitsubishi-Nagasaki Shipyard | (November 1943) | | (December 1945) | Cancelled on 5 May 1944 |
| 5009 | | Yokosuka Naval Arsenal | (July 1943) | | (March 1946) | Cancelled on 11 August 1943 |
| 5010 | | Mitsubishi-Nagasaki Shipyard | (April 1944) | | (June 1946) | Cancelled on 11 August 1943 |
| 5011 | | Yokosuka Naval Arsenal | (June 1944) | | (September 1946) | Cancelled on 11 August 1943 |
| 5012 | | Kure Naval Arsenal | (June 1944) | | (September 1946) | Cancelled on 11 August 1943 |
| 5013 | | Yokosuka Naval Arsenal | (June 1944) | | (March 1947) | Cancelled on 11 August 1943 |
| 5014 | | Yokosuka Naval Arsenal | (October 1944) | | (September 1947) | Cancelled on 11 August 1943 |
| 5015 | | Yokosuka Naval Arsenal | (January 1945) | | (March 1948) | Cancelled on 11 August 1943 |

## Photos

* Amagi wrecked at Kure, October 1945
* Amagi, August 1946
* Katsuragi and Kaiyo (above) under attack on 19 March 1945
* Katsuragi as repatriation transport on 31 January 1946
* Kasagi, 2 November 1945
* Aso, 20 December 1946
* Ikoma, 23 May 1946

## Footnotes

* ↑ Senshi Sōsho Vol.31 (1969), p.815
* ↑ Senshi Sōsho Vol.88 (1975), p.37
* 1 2 3 4 5 6 7 8 9 10 11 Ships of the World (1994), p.66
* 1 2 3 4 5 6 7 8 9 Shizuo Fukui, p.442–445
* ↑ The Maru Special (1981), p.17–19, p.54–55 and p.84–87
* ↑ Ships of the World (1994), p.177
* 1 2 3 4 Japan Center for Asian Historical Records, p.3
* 1 2 3 4 Shizuo Fukui, p.276
* 1 2 Rekishi Gunzo, p.105
* 1 2 Lengerer 2010b, p. 106
* 1 2 3 4 Stille (2005), p. 37
* ↑ Stille (2005), p. 38
* ↑ Shizuo Fukui, p.273
* 1 2 3 Shizuo Fukui, p.274
* 1 2 3 The Maru Special (1981), p.55
* ↑ Shizuo Fukui, p.331
* 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Senshi Sōsho Vol.88 (1975), p.18
* 1 2 Shizuo Fukui, p.275
* ↑ The Maru Special (1979), p.38
* ↑ Daiji Katagiri, p.83–84
* ↑ Senshi Sōsho Vol.88 (1975), p.95
* ↑ Senshi Sōsho Vol.88 (1975), p.71–74