Japan’s second Asahi-class destroyer, the JS Shiranui (Unknown Fire), entered Japan Maritime Self Defense Force (JMSDF) service in a ceremony at Mitsubishi Heavy Industries (MHI)’ Nagasaki Shipyard Nagasaki Shipyard on February 27. Shiranui is the third ship to hold the name after the Murakumo and Kagerō class destroyers. JS Asahi DD-119, the lead ship in the class was commissioned a year before, on March 8, 2018. It is the third ship to hold the name after the Murakumo and Kagerō class destroyers. The destroyer is assigned to the JMSDF’s Escort Division 7 based at Ōminato Base in Aomori Prefecture. JS Shiranui (DD-120) was launched in October 2017 and was commissioned without delays.
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. This 5,100-ton general-purpose escort destroyers class used to be designated “25DD” – referring to a date on the Japanese calendar, specifically the 25th fiscal year of the Heisei period (2013). The procurement of KS Asahi (119) destroyer began in 2013 in response to the reduction in the number of destroyers within the JMSDF. JS Shiranui (DD-120) destroyer was procured a year later.
The two major characteristics of Asahi-class destroyers is its bigger emphasis on anti-submarine warfare and the adoption of the COGLAG (combined gas turbine electric and gas turbine) propulsion system. They measure 151 meters in length and reach speeds of 30 knots, according to the Japan defense ministry. Asahi-class destroyers are the first JMSDF ships to deploy with periscope detection radars in addition to being equipped with new towed array sonars. Armament includes Mark 41 vertical launch systems for self protection, 62-caliber naval guns, close-in weapon systems and two Mark 32 surface vessel torpedo tubes. The destroyers will have a complement of around 230 and embark one Mitsubishi-built SH-60J/K are anti-submarine patrol helicopter.
Another unique feature about this destroyer is the usage of a GaN-AESA (Gallium nitride – Active electronically scanned array) Multifunction Radar. According to Navy Recognition, to their knowledge the Asahi-class is the first Japanese and the world’s second class of warship to be outfitted with this technology (the first being the German Baden-Württemberg-class frigate with their TRS-4D radar). The destroyer’s radar is based on the FCS-3A radar used for the Akizuki-class but uses Gallium nitride to improve performance. 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.