Asahi-class destroyer

The Asahi class of destroyers of the Japan Maritime Self-Defense Force is optimized for undersea warfare. The class was initially designated "25DD", referring to a date on the Japanese calendar, specifically the 25th fiscal year of the Heisei period (2013).

JS Shiranui (DD-120)
Class overview
Builders:	Mitsubishi Heavy Industries
Operators:	Japan Maritime Self-Defense Force
Preceded by:	Akizuki class
Cost:	DD119: JPY72.3 billion[1] $893 million (constant 2009 USD)
Built:	2015–2019
In service:	2018-present
In commission:	2018–present
Completed:	2[2]
Active:	2
General characteristics
Type:	Guided missile destroyer
Displacement:	5,100 tonnes standard 6,800 tonnes full load
Length:	151 m (495 ft 5 in)
Beam:	18.3 m (60 ft 0 in)
Draft:	5.4 m (17 ft 9 in)
Depth:	10.9 m (35 ft 9 in)
Propulsion:	COGLAG, two shafts, two GE LM2500 turbines
Speed:	30 kn (56 km/h; 35 mph)
Complement:	230
Sensors and processing systems:	OYQ-13 ACDS FCS-3A AAW system OPY-1 AAW system OQQ-24 ASW system OQR-4 Towed sonar array system NOLQ-3D-2 EW system OPS-48 surface search radar
Armament:	1 × Mk. 45 Mod 4 127 mm (5 in)/62 gun 8 × Type 90 Anti-ship missile in quad canisters 2 × 20 mm Phalanx Block1B CIWS 2 × HOS-303 triple 324 mm (12.8 in) torpedo tubes Anti-torpedo System 32-cell Mk. 41 Vertical launching system RIM-162 ESSM SAM RUM-139 VL-ASROC Type 07 VL-ASROC
Aircraft carried:	1 × SH-60K helicopter

The lead ship, Asahi, is the third ship to hold the name after the Asahi-class destroyer escort lent from the United States Navy in 1955, and the Imperial Japanese battleship. The second ship of the class, Shiranui, is the third ship to hold the 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 Hatsuyuki class) within the JMSDF. The two major characteristics of this destroyer is its bigger emphasis on anti-submarine warfare and the adoption of the COGLAG (combined gas turbine electric and gas turbine) propulsion system. A second destroyer was procured a year later.[3][4]

Design

The Asahi class is based on the existing Akizuki-class destroyer to reduce acquisition cost and allow future development and growth. Unlike the Akizuki class (which focuses on anti-aircraft warfare) the Asahi class focuses on anti-submarine warfare.[5]

Features

The Asahi class is the first Japanese warship to be equipped with a COGLAG propulsion system. This allows the destroyer to be more fuel efficient than previous warships. Another unique feature about this destroyer is the usage of a GaN-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.[5] In radar technology, gallium nitride offers a number of advantages over the traditionally used gallium arsenide (GaA). These advantages include higher power density, efficiency, thermal spreading and frequency coverage. This in turn allows the GaN chip to be smaller than their GaA counterpart, thus reducing cost and increasing overall cost effectiveness.[6]

Ships in the class

Building no.	Pennant no.	Name/Namesake	Laid down	Launched	Commissioned	Shipyard
1613	DD-119	Asahi (Morning Sun)	4 August 2015	19 October 2016	7 March 2018	MHI, Nagasaki
1614	DD-120	Shiranui (Phosphorescent Light)	20 May 2016	12 October 2017	27 February 2019	MHI, Nagasaki

References

1. Pike, John. "25DD Multipurpose Destroyer". www.globalsecurity.org. Retrieved 20 March 2018.
2. https://thediplomat.com/2019/03/japan-commissions-new-anti-submarine-warfare-destroyer/
3. "Defense Programs and Budget of Japan Overview of FY2013 Budget" (PDF). Japan Ministry of Defense. January 2013. Archived from the original (PDF) on 19 October 2013. Retrieved 8 January 2019.
4. "Defense Programs and Budget of Japan Overview of FY2014 Budget" (PDF). Japan Ministry of Defense. December 2013. Archived from the original (PDF) on 2 March 2014. Retrieved 8 January 2019.
5. "First JMSDF 25DD-class Asahi ASW Destroyer Started Sea Trials". Navy Recognition. 27 July 2017. Retrieved 8 January 2019.
6. Colin S. Whelan, Nicholas J. Kolias, Steven Brierley, Chris MacDonald, Steven Bernstein (23–26 April 2012). "GaN Technology for Radars" (PDF). pairserver. Retrieved 8 January 2019.CS1 maint: multiple names: authors list (link)