The four were
light cruiser
A light cruiser is a type of small or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck. Prior to thi ...
s operated by the
Imperial Japanese Navy
The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...
. All were named after Japanese rivers. Larger than previous Japanese light cruisers, the ''Agano''-class vessels were fast, but with little protection, and were under-gunned for their size (albeit with a powerful offensive torpedo armament, able to launch up to eight Type 93 "Long Lance" torpedoes in a salvo). They participated in numerous actions during
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
.
The ''Agano'' class was followed by the larger , of which only a single vessel was completed.
Background
The Imperial Japanese Navy had developed a standardized design for light cruisers as flagships for
destroyer
In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort
larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in ...
and
submarine
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...
squadrons, based on a 5,500 ton displacement, shortly after
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
. 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
The London Naval Treaty, officially the Treaty for the Limitation and Reduction of Naval Armament, was an agreement between the United Kingdom, Japan, France, Italy, and the United States that was signed on 22 April 1930. Seeking to address is ...
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.
[Stille, ''Imperial Japanese Navy Light Cruisers 1941-45'', pages 34-39;] 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
A funnel is a tube or pipe that is wide at the top and narrow at the bottom, used for guiding liquid or powder into a small opening.
Funnels are usually made of stainless steel, aluminium, glass, or plastic. The material used in its construct ...
. Unlike most Japanese designs, the ''Agano'' class was not overweight, so it exhibited good stability and seaworthiness.
The ships measured
long overall
__NOTOC__
Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, an ...
with a
beam
Beam may refer to:
Streams of particles or energy
*Light beam, or beam of light, a directional projection of light energy
**Laser beam
*Particle beam, a stream of charged or neutral particles
**Charged particle beam, a spatially localized grou ...
of and had a
draft
Draft, The Draft, or Draught may refer to:
Watercraft dimensions
* Draft (hull), the distance from waterline to keel of a vessel
* Draft (sail), degree of curvature in a sail
* Air draft, distance from waterline to the highest point on a vesse ...
of . They
displaced at
standard load
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into wei ...
and at
deep load
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into wei ...
.
[Whitley, p. 186] 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 turbine
A steam turbine is a machine that extracts thermal energy from pressurized steam and uses it to do mechanical work on a rotating output shaft. Its modern manifestation was invented by Charles Parsons in 1884. Fabrication of a modern steam turbin ...
s, each driving a single
propeller shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...
, using steam provided by six
Kampon
The was the externally operating division of the Ministry of the Navy of Japan responsible for the administration of naval vessel construction. From 1923 onward, it took on the role of a research institution for the research and development of n ...
Ro Gō
water-tube boiler
A high pressure watertube boiler (also spelled water-tube and water tube) is a type of boiler in which water circulates in tubes heated externally by the fire. Fuel is burned inside the furnace, creating hot gas which boils water in the steam-gene ...
s. The turbines were designed to produce a total of and give the ships a speed of . The ships carried enough
fuel oil
Fuel oil is any of various fractions obtained from the distillation of petroleum (crude oil). Such oils include distillates (the lighter fractions) and residues (the heavier fractions). Fuel oils include heavy fuel oil, marine fuel oil (MFO), bun ...
to give them a range of at a speed of .
[Jentschura, Jung & Mickel, p. 111]
Armament and protection
The main armament of the ''Agano'' class consisted of six
41st Year Type guns in three twin-
gun turret
A gun turret (or simply turret) is a mounting platform from which weapons can be fired that affords protection, visibility and ability to turn and aim. A modern gun turret is generally a rotatable weapon mount that houses the crew or mechani ...
s, two in front of the
superstructure
A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships.
Aboard ships and large boats
On water craft, the superstruct ...
and one
aft. The secondary armament included four
98th Year Type anti-aircraft (AA) guns in two twin turrets
amidships
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water (mostly though not necessarily on the sea). Some remain current, while many date from the 17th t ...
.
[ The suite of light anti-aircraft weapons included a pair of triple mounts for Type 96 AA guns and two twin-gun mounts for Type 93 ]anti-aircraft machinegun
Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, ...
s. The ships also had two quadruple torpedo launchers for Type 93 (''Long Lance'') torpedoes on the centerline and had a reload system with eight spare torpedoes. The ''Agano''-class ships were also fitted with a pair of Aichi E13A
The Aichi E13A ( Allied reporting name: "Jake") was a long-range reconnaissance seaplane used by the Imperial Japanese Navy (IJN) from 1941 to 1945. Numerically the most important floatplane of the IJN, it could carry a crew of three and a bomblo ...
floatplane
A floatplane is a type of seaplane with one or more slender floats mounted under the fuselage to provide buoyancy. By contrast, a flying boat uses its fuselage for buoyancy. Either type of seaplane may also have landing gear suitable for land, ...
s and a catapult
A catapult is a ballistic device used to launch a projectile a great distance without the aid of gunpowder or other propellants – particularly various types of ancient and medieval siege engines. A catapult uses the sudden release of stored p ...
. The first two vessels in the class (''Agano'' and ''Noshiro'') had a larger catapult, while the later ''Yahagi'' and ''Sakawa'' had a shorter 19-meter catapult. To detect submarines, the ''Agano''s were equipped with a Type 93 Model 2 hydrophone
A hydrophone ( grc, ὕδωρ + φωνή, , water + sound) is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones are based on a piezoelectric transducer that generates an electric potenti ...
installation and a Type 93 Model 3 sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigation, navigate, measure distances (ranging), communicate with or detect o ...
. They were equipped with two depth charge
A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive Shock factor, hydraulic shock. Most depth ...
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 8cm 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 8cm guns and extra light antiaircraft guns.
The propulsion machinery was protected by a waterline armor belt
Belt armor is a layer of heavy metal armor plated onto or within the outer hulls of warships, typically on battleships, battlecruisers and cruisers, and aircraft carriers.
The belt armor is designed to prevent projectiles from penetrating ...
thick with transverse bulkheads at fore and aft of the machinery and a middle deck of the same thickness. The ships' magazine
A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...
s were enclosed in armored boxes with sides, 20-millimeter tops and 20- or 25-millimeter ends. The armor protecting the steering gear ranged from in thickness and the armor plates on the gun turrets were 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
was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy.
History
The Sasebo Naval District was established at Sasebo, Nagasaki in 1886, as the third of the naval districts responsible for the defense of the ...
and one from Yokosuka Naval Arsenal
was one of four principal naval shipyards owned and operated by the Imperial Japanese Navy, and was located at Yokosuka, Kanagawa prefecture on Tokyo Bay, south of Yokohama.
History
In 1866, the Tokugawa shogunate government established the ...
.
''Agano''
Completed on 31 October 1942, ''Agano'' participated in the battles for Guadalcanal
Guadalcanal (; indigenous name: ''Isatabu'') is the principal island in Guadalcanal Province of Solomon Islands, located in the south-western Pacific, northeast of Australia. It is the largest island in the Solomon Islands by area, and the seco ...
and the Solomon Islands
Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...
during 1943. ''Agano'' was badly damaged in Rabaul
Rabaul () is a township in the East New Britain province of Papua New Guinea, on the island of New Britain. It lies about 600 kilometres to the east of the island of New Guinea. Rabaul was the provincial capital and most important settlement in ...
harbor by aircraft from the aircraft carrier
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...
s 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''
Commissioned on 30 June 1943, ''Noshiro'' participated in operations in the Solomon Islands and was damaged during the US carrier aircraft raids on Rabaul
Rabaul () is a township in the East New Britain province of Papua New Guinea, on the island of New Britain. It lies about 600 kilometres to the east of the island of New Guinea. Rabaul was the provincial capital and most important settlement in ...
on 5 November 1943. She served in the Marianas
The Mariana Islands (; also the Marianas; in Chamorro: ''Manislan Mariånas'') are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, betw ...
in the summer of 1944, and was part of Admiral Kurita's force during the Battle of the Philippine Sea
The Battle of the Philippine Sea (June 19–20, 1944) was a major naval battle of World War II that eliminated the Imperial Japanese Navy's ability to conduct large-scale carrier actions. It took place during the United States' amphibious invas ...
. At the Battle of Leyte Gulf
The Battle of Leyte Gulf ( fil, Labanan sa golpo ng Leyte, lit=Battle of Leyte gulf; ) was the largest naval battle of World War II and by some criteria the largest naval battle in history, with over 200,000 naval personnel involved. It was fou ...
in October 1944. She was west of Panay
Panay is the sixth-largest and fourth-most populous island in the Philippines, with a total land area of and has a total population of 4,542,926 as of 2020 census. Panay comprises 4.4 percent of the entire population of the country. The City o ...
while withdrawing from the Battle off Samar
The Battle off Samar was the centermost action of the Battle of Leyte Gulf, one of the largest naval battles in history, which took place in the Philippine Sea off Samar Island, in the Philippines on October 25, 1944. It was the only major ...
on the morning of 26 October when she was sunk by aircraft from and .
''Yahagi''
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''
''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
Bikini Atoll ( or ; Marshallese: , , meaning "coconut place"), sometimes known as Eschscholtz Atoll between the 1800s and 1946 is a coral reef in the Marshall Islands consisting of 23 islands surrounding a central lagoon. After the Second ...
in 1946.Combined Fleet.com IJN Sakawa Tabular Record of Movement
/ref>
References
Sources
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External links
{{DEFAULTSORT:Agano-class cruiser
Cruiser classes