JS Kaga
JS Kaga (DDH-184) is the second ship of the Izumo-class helicopter destroyers in service with the Japan Maritime Self-Defense Force.[1] Commissioned on 22 March 2017, the vessel was initially designed for anti-submarine warfare, amphibious operations, and disaster relief missions, with a full-load displacement of approximately 27,000 tons and capacity for up to 14 helicopters.[1][2] Following Japan's decision to acquire F-35B short take-off and vertical-landing aircraft, Kaga entered modifications in 2023, including flight deck reshaping and application of heat-resistant coatings to withstand jet exhaust, with the first phase completed on 29 March 2024.[3] These alterations enable the ship to embark up to 12 F-35B fighters alongside helicopters, effectively transforming it into a light aircraft carrier while adhering to Japan's constitutional prohibitions on offensive capabilities by classifying it as a multi-role destroyer.[3][4] In October 2024, Kaga conducted its first F-35B flight operations off the coast of California, validating the modifications during trials with U.S. forces.[4] By February 2025, it undertook its inaugural operational deployment as an F-35B-capable platform in the Philippine Sea, underscoring enhancements to Japan's power projection in response to evolving Indo-Pacific security dynamics.[5]Development and Construction
Planning and Design Origins
The Izumo-class helicopter destroyers, including JS Kaga (DDH-184), were conceived as successors to the aging Shirane-class vessels commissioned in the early 1980s, which had limited capacity for only three helicopters and were nearing decommissioning by the late 2000s. The Japan Maritime Self-Defense Force (JMSDF) identified the need for larger platforms to bolster anti-submarine warfare (ASW) capabilities amid rising regional submarine threats, while also supporting multi-role functions such as disaster relief and sea lane protection. Design requirements prioritized a full-length flight deck for up to 14 rotary-wing aircraft, primarily SH-60K and MCH-101 helicopters, integrated with advanced phased-array radars and vertical launch systems for enhanced situational awareness and missile defense.[6][7] The Japanese Ministry of Defense formally announced plans for the 22DDH program on November 23, 2009, allocating initial funding of approximately 113.9 billion yen (about $1.5 billion at the time) for the lead ship, with the class emphasizing defensive operations under Japan's constitutional restrictions on offensive naval power projection. JS Kaga, as the second unit, was authorized in the fiscal year 2012 defense budget to ensure fleet redundancy and operational flexibility, reflecting JMSDF priorities for sustained ASW patrols in the East China Sea and Philippine Sea. The design incorporated lessons from the preceding Hyūga-class, scaling up displacement to around 19,500 tons standard and incorporating hybrid propulsion for improved endurance, though initial specifications avoided fixed-wing compatibility to maintain the "helicopter destroyer" designation.[6][8] Early conceptualization drew from operational analyses post-2000s defense reviews, which highlighted vulnerabilities in JMSDF's helicopter assets against peer adversaries' submarine fleets, leading to specifications for modular hangars and reinforced decking for heavier aircraft loads. Despite debates over potential carrier-like roles—attributed by analysts to regional power balances—the official rationale centered on empirical ASW needs, with no provisions for catapults or arrestor wires in the original blueprint.[9][10]Construction and Commissioning
The keel of JS Kaga (DDH-184), second vessel of the Izumo-class multi-role helicopter destroyers, was laid down on 7 October 2013 by Japan Marine United at its Yokohama shipyard.[1][11] Construction proceeded over the subsequent two years, incorporating design features for anti-submarine warfare, disaster relief, and border security operations, with capacity for up to 14 helicopters.[2] Kaga was launched on 27 August 2015 during a ceremony at the same Yokohama facility, marking the completion of her hull assembly and initial outfitting phases.[12][2] After extensive fitting-out, systems integration, and sea trials, Kaga was formally commissioned into the Japan Maritime Self-Defense Force on 22 March 2017, joining the JMSDF Escort Flotillas as flagship of Flotilla 1 and basing at Kure Naval Base in Hiroshima Prefecture.[1][2] The commissioning enhanced Japan's naval aviation projection capabilities, with the 19,500-ton vessel displacing approximately 27,000 tons at full load and crewed by around 520 personnel.[1]Technical Specifications
Dimensions and Displacement
The JS Kaga measures 248 meters in overall length, 38 meters in beam, and 7.5 meters in draft.[6][13] These dimensions, shared with its sister ship Izumo, accommodate up to 14 helicopters in its original configuration and provide a through-deck length exceeding 200 meters for aviation operations.[6] The vessel has a standard displacement of 19,500 tonnes and a full load displacement of 27,000 tonnes.[6][13] Post-conversion modifications for fixed-wing aircraft compatibility, completed in 2025, did not alter these baseline figures, as changes were limited to deck surfacing and superstructure adjustments without hull expansion.[13]| Parameter | Measurement |
|---|---|
| Length (overall) | 248 m |
| Beam (maximum) | 38 m |
| Draft | 7.5 m |
| Displacement (standard) | 19,500 tonnes |
| Displacement (full load) | 27,000 tonnes |