Agano-class cruiser

Background

The Imperial Japanese Navy had developed a standardized design for light cruisers as flagships for destroyer and submarine squadrons, based on a 5,500 ton displacement, shortly after World War I. However, by the 1930s these vessels were obsolete, as contemporary destroyers were faster, carried more powerful armament, and had greater endurance. As soon as the restrictions of the London Naval Treaty were removed, the Navy General Staff developed a plan within the Fourth Fleet Supplemental Budget to build 13 new 6000 ton cruisers between 1939 and 1945 to replace the , , and s. These vessels were intended to be the flagships for six destroyer squadrons and seven submarine squadrons. The new design was finalised in October 1937; however, construction was delayed due to overloading of the Japanese shipyards. Construction costs came to 16.4 million yen per vessel.

Design and description

The design for the Agano class was based on technologies developed for the light cruiser , resulting in a graceful and uncluttered deck line and single funnel. Unlike most Japanese designs, the Agano class was not overweight, so it exhibited good stability and seaworthiness. The ships measured 174.1 m long overall with a beam of 15.2 m and had a draft of 5.63 m. They displaced 6652 t at standard load and 8534 t at deep load. The ships had a crew of 51 officers and 649 enlisted men; assignment as a flagship added 6 officers and 20 more sailors.

The Agano class had four geared steam turbines, each driving a single propeller shaft, using steam provided by six Kampon Ro Gō water-tube boilers. The turbines were designed to produce a total of 100000 shp and give the ships a speed of 35 kn. The ships carried enough fuel oil to give them a range of 6300 nmi at a speed of 18 kn.

Armament and protection

The main armament of the Agano class consisted of six 15 cm 41st Year Type guns in three twin-gun turrets, two in front of the superstructure and one aft. The secondary armament included four 8 cm 98th Year Type anti-aircraft (AA) guns in two twin turrets amidships. The first two vessels in the class (Agano and Noshiro) had a larger 26 m catapult, while the later Yahagi and Sakawa had a shorter 19-meter catapult. To detect submarines, the Aganos were equipped with a Type 93 Model 2 hydrophone installation and a Type 93 Model 3 sonar. They were equipped with two depth charge chutes for 18 depth charges.

It was originally supposed to equip them with nine 155mm guns in three triple turrets like those used in their successor, triple torpedo tubes and no 8 cm guns, but the triple 155mm turrets were too large for the ships. Therefore the main battery was changed to four twin 152mm turrets. Then it was decided to strengthen the torpedo armament, so number three turret was removed, and the weight saved went into quad torpedo tubes, the 8 cm guns and extra light antiaircraft guns.

The propulsion machinery was protected by a waterline armor belt 60 mm thick with 20 mm transverse bulkheads at fore and aft of the machinery and a middle deck of the same thickness. The ships' magazines were enclosed in armored boxes with 55 mm sides, 20-millimeter tops and 20- or 25-millimeter ends. The armor protecting the steering gear ranged from 16 - in thickness and the armor plates on the gun turrets were 19 mm thick.

All of the vessels in the class were updated with additional anti-aircraft weaponry and radar at various points in their service lives.

Ships in class

Four ships were budgeted under the 1939 4th Naval Replenishment Programme, three from the Sasebo Naval Arsenal and one from Yokosuka Naval Arsenal.

''Agano''

Main article: Japanese cruiser Agano

Completed on 31 October 1942, Agano participated in the battles for Guadalcanal and the Solomon Islands during 1943. Agano was badly damaged in Rabaul harbor by aircraft from the aircraft carriers and , and in a subsequent attack by aircraft from TF38 on 11 November she received a torpedo hit. Ordered to home waters for repair, she was torpedoed and sunk north of Truk by the US submarine , on 16 February 1944.

''Noshiro''

Main article: Japanese cruiser Noshiro

Commissioned on 30 June 1943, Noshiro participated in operations in the Solomon Islands and was damaged during the US carrier aircraft raids on Rabaul on 5 November 1943. She served in the Marianas in the summer of 1944, and was part of Admiral Kurita's force during the Battle of the Philippine Sea. At the Battle of Leyte Gulf in October 1944. She was west of Panay while withdrawing from the Battle off Samar on the morning of 26 October when she was sunk by aircraft from and .

''Yahagi''

Main article: Japanese cruiser Yahagi (1942)

Commissioned on 29 December 1943 Yahagi saw action in the Marianas in May/June 1944, during the Battle of the Philippine Sea, and during the Battle of Leyte Gulf. After the US invasion of Okinawa on 1 April 1945, she was ordered to accompany the battleship on its suicide mission against the American fleet at Okinawa. Yahagi was hit by some seven torpedoes as well as a dozen bombs, and sank on the afternoon of 7 April 1945.

''Sakawa''

Main article: Japanese cruiser Sakawa

Sakawa was not completed until the end of 1944, by which time there was little fuel available. She survived the war unscratched and was used as a transport to return demilitarized troops from New Guinea and other areas after the war. She was expended in the atom bomb tests at Bikini Atoll in 1946.

References

Sources

References

1. Nishida, Nishida. (2002). "Agano-class light cruisers". Imperial Japanese Navy.
2. Jentsura, Hansgeorg. (1976). "Warships of the Imperial Japanese Navy, 1869-1945". Naval Institute Press.
3. Stille, ''Imperial Japanese Navy Light Cruisers 1941-45'', pages 34-39;
4. Whitley, p. 186
5. Lacroix & Wells, p. 591
6. Jentschura, Jung & Mickel, p. 111
7. The suite of light anti-aircraft weapons included a pair of triple mounts for [[Type 96 25 mm AT/AA Gun. {{convert. 2.5. cm. 0. {{cvt. 13.2. mm. 1 Type 93]] [[anti-aircraft machinegun]]s. The ships also had two quadruple torpedo launchers for [[Type 93 torpedo. {{convert. 61. cm. catapult]].Lacroix & Wells, pp. 571–72, 579–580
8. Lacroix & Wells, pp. 579–581
9. Lacroix & Wells, pp. 563–564
10. [http://combinedfleet.com/agano_t.htm Combined Fleet.com IJN Agano Tabular Record of Movement]
11. [http://combinedfleet.com/noshiro_t.htm Combined Fleet.com IJN Noshiro Tabular Record of Movement]
12. [http://combinedfleet.com/yahagi_t.htm Combined Fleet.com IJN Yahagi Tabular Record of Movement]
13. [http://combinedfleet.com/sakawa_t.htm Combined Fleet.com IJN Sakawa Tabular Record of Movement]