The ''Asahi'' class of

destroyers In naval terminology, a destroyer is a fast, maneuverable, long-endurance warship intended to escort larger vessels in a fleet, convoy, or carrier battle group and defend them against a wide range of general threats. They were conceived i ...

is a class of warships of the

Japan Maritime Self-Defense Force The , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy ( ...

. The ''Asahi'' is largely based on the ''Akizuki''-class destroyer; while the ''Akizuki''-class specialized in

anti-air warfare Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface ( submarine-launched), and air-bas ...

, the ''Asahi''-class was designed to specialize in

anti-submarine warfare Anti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations ar ...

. The design was initially designated "25DD", referring to a date on the

Japanese calendar Japanese calendar types have included a range of official and unofficial systems. At present, Japan uses the Gregorian calendar together with year designations stating the Japanese era name, year of the reign of the current Emperor. The written f ...

, specifically the 25th fiscal year of the

Heisei period The was the Japanese era name, period of Japanese history corresponding to the reign of Emperor Akihito from 8 January 1989 until his 2019 Japanese imperial transition, abdication on 30 April 2019. The Heisei era started on 8 January 1989, the ...

(2013), the year that procurement of the class began. The lead ship, ''Asahi'', is the third ship to hold the name after the ''Asahi''-class destroyer escort lent from the

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

in 1955, and the Imperial Japanese battleship. The second ship of the class, ''Shiranui'', is the third ship to hold its name after the ''Murakumo'' and ''Kagerō''-class destroyers.

Development

The procurement of the destroyer began in 2013 in response to the reduction in the number of destroyers (namely the ) within the JMSDF. The two major characteristics of this destroyer is its bigger emphasis on

and the adoption of a COGLAG (combined gas turbine electric and gas turbine: a modification of the

combined gas and gas Combined gas turbine and gas turbine (COGAG) is a type of propulsion system for ships using two gas turbines connected to a single propeller shaft. A gearbox and clutches allow either of the turbines to drive the shaft or both of them combined. M ...

propulsion system employing electric propulsion system for low-speed cruising) propulsion system. A second destroyer was procured a year later.

Design

The ''Asahi'' class is based on the existing to reduce acquisition cost and allow future development and growth. Unlike the ''Akizuki'' class, which focuses on

anti-aircraft warfare Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface (Submarine#Armament, submarine-lau ...

, the ''Asahi'' class focuses on anti-submarine warfare.

Features

The ''Asahi'' class is the first class of Japanese warships to be equipped with a COGLAG propulsion system, allowing the class to be more fuel efficient than previous warships. Another unique feature of this destroyer is the usage of a

GaN The word Gan or the initials GAN may refer to: Places * Gan, a component of Hebrew placenames literally meaning "garden" China * Gan River (Jiangxi) * Gan River (Inner Mongolia), * Gan County, in Jiangxi province * Gansu, abbreviated '' ...

- AESA (gallium nitride - active electronically scanned array) multifunction radar. The ''Asahi'' class is the second Japanese class of warship to be outfitted with this technology (the ''Akizuki'' class was the first). The destroyer's radar is based on the FCS-3A radar used for the ''Akizuki'' class and uses gallium nitride to improve performance. In radar technology, gallium nitride offers a number of advantages over the typically used

gallium arsenide Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a Zincblende (crystal structure), zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monoli ...

(GaA). These advantages include higher power density, efficiency, thermal spreading and frequency coverage. In turn, this allows the GaN chip to be smaller than their GaA counterpart, thus reducing cost and increasing overall cost effectiveness.

Ships in the class

References

{{Combatant ship classes of the Japan Maritime Self-Defense Force