Photos circulating online show Japan’s prototype electromagnetic railgun mounted on the JS Asuka test ship.
Images shared on June 30 by user @HNlEHupY4Nr6hRM on X reveal the railgun installed on the stern deck of the 6,200-ton experimental vessel.
🇯🇵海自試験艦「あすか ASE-6102」
いつもはｼｰﾄに覆われて見えないﾚｰﾙｶﾞﾝが、今日はｶﾊﾞｰだけでなくｹｰｽのﾌﾟﾚｰﾄも外されて、無数の突起物がある砲身まで現れました😲 pic.twitter.com/vEY0ujt9GT
— モリジュン (@HNlEHupY4Nr6hRM) June 30, 2025
The Asuka, developed and built by Sumitomo Heavy Industries, was first seen equipped with the turreted railgun on its stern flight deck in April.
Railgun prototype onboard JMSDF experimental ship JS Asuka pic.twitter.com/yA2ZRayty5
— Vodka 🧊 (@vodk_anon) April 18, 2025
The prototype electromagnetic railgun mounted on the ship was developed by Japan’s Acquisition, Technology & Logistics Agency (ATLA).
According to BulgarianMilitary.com, the prototype weighs approximately 8 tons and is equipped with a 6-meter barrel designed to fire 40mm projectiles weighing around 320 grams.
The system operates at an energy level of 5 megajoules (MJ), with Japan’s ATLA aiming to scale it up to 20 MJ in future versions to significantly increase its range and destructive capability.
Railguns offer advantages over conventional naval guns: faster projectiles, simpler logistics, and lower costs per shot. They also outperform lasers in adverse weather and have potential as hypersonic missile countermeasures. However, challenges remain, including barrel wear, power demands, and heat dissipation.
The U.S. Navy ended its railgun efforts in 2021 due to similar technical hurdles.
Japan’s prototype railgun is scheduled for at-sea testing by the end of July 2025.
