Japan’s Acquisition Technology & Logistics Agency (ATLA) has released new pictures from testing of a prototype electromagnetic railgun aboard the testbed warship JS Asuka earlier this year. ATLA also asserts that it is the first time anyone has successfully fired a ship-mounted railgun at an actual target vessel. Japan continues to push ahead with railgun development, a technology the U.S. Navy notably halted work on in the early 2020s, despite showing promise, due to significant technological hurdles.
JS Asuka, a one-of-its-kind dedicated experimental vessel with a 6,200-ton-displacement belonging to the Japan Maritime Self-Defense Force (JMSDF), was first spotted with the railgun in a turret installed on its stern flight deck in April, as TWZ reported on at the time. Additional views of the ship in this configuration emerged afterward.
“ATLA conducted the Ship-board Railgun Shooting Test from June to early July this year with the support of the Japan Maritime Self-Defense Force,” according to a post yesterday on the agency’s official Instagram page. “It’s the first time that a ship-mounted railgun was successfully fired at a real ship.”
One of the pictures accompanying ATLA’s Instagram post, seen at the top of this story, which was also shared on the agency’s other social media accounts, shows the railgun being fired. What looks to be a radar array and an electro-optical and/or infrared camera system are also seen in the image on a separate turret.
Another, seen below, shows a tug-like ship in the crosshairs of a targeting system. Additional pictures of the tug have now also emerged clearly showing target boards on the port and starboard sides of its funnel, as well as one facing the stern.
So far, ATLA has not released any imagery of target vessels actually being struck by projectiles fired from the railgun mounted on Asuka. The agency says more details will be provided at its upcoming Defense Technology Symposium in November.
Back in 2023, ATLA said it had conducted the first-ever successful firing of a railgun from any ship. The agency did not name the vessel used in those tests.
ATLA has been working on railguns since the mid-2010s and has also conducted test firings at facilities on land. The agency and the JMSDF have a clear eye toward developing an operational weapon that could be integrated onto Japanese warships.
ATLA has previously shown renderings of potential railgun installations on the future 13DDX destroyer, as well as existing Maya class destroyers (also known as the 27DDG class). The Japanese Ministry of Defense has also publicly shown a model of a railgun in a much more streamlined turret compared to the one tested aboard Asuka.
The video from ATLA below, which the agency put out last year, also depicts ground-based truck-mounted railguns.
Speaking through an interpreter at a panel discussion at the DSEI Japan 2025 exposition earlier this year, Kazumi Ito, principal director of the equipment policy division at ATLA, said his country’s railgun efforts were “progressing,” but acknowledged “various challenges,” according to National Defense Magazine.
Railguns use electromagnets instead of chemical propellants to fire projectiles at very high velocities. Historically, they have had significant power generation and cooling requirements, which has, in turn, typically made them physically very bulky. As TWZ has previously noted, mounting the experimental railgun turret on Asuka‘s flight deck made good sense given the ample open space it offered. A more traditional installation on an operational warship would require finding sufficient space, especially below deck, for the various components, which could require extensive modifications that are costly and time-consuming.
The wear and tear that comes from sustained firing of projectiles at very high speeds presents additional challenges for railguns. Rapidly worn-out barrels can lead to degraded range and accuracy, and increase the risk of a catastrophic failure.
ATLA has reportedly been able to demonstrate the ability to fire rounds at a velocity of around 4,988 miles per hour (2,230 meters per second; Mach 6.5) while using five megajoules (MJ), or 5 million joules (J), of charge energy in previous tests. The agency has at least previously had a goal of achieving a muzzle velocity of at least 4,473 miles-per-hour (2,000 meters-per-second) and a barrel life of 120 rounds are among previous testing goals, according to Naval News. Separate reports have said that ATLA has been trying to reduce the weapon’s power demands, as well.
At the same time, the potential rewards from developing a practical railgun suitable for operational military use are great. In addition to applications against targets at sea and on land, the weapons have long held promise in the anti-air role. As TWZ has written in the past:
“In principle, a practical electromagnetic railgun would offer a highly capable and flexible weapon system that can rapidly engage a wide array of targets at sea, on land, and even in the air, and at considerable ranges. Japan has previously expressed interest in this capability explicitly to help protect against incoming hypersonic threats. Such a weapon would also offer benefits in terms of magazine depth and cost compared to traditional surface-to-air and surface-to-surface missiles, given the small size and lower unit price of the individual rounds.”
“When it comes to warships, in particular, where physical space is at a premium and where options for reloading missiles at sea can be at best extremely limited, having a weapon system firing lower-cost munitions from a large magazine and that can engage a broad swath of target sets would be a clear boon.”
With its potential capabilities, Japan has not been alone in pursuing railguns, especially for naval applications. The U.S. Navy was notably active in this realm between 2005 and 2022, but, despite promising progress for a time, shelved that work in the end in the face of persistent technical issues. By that point, plans for an at-sea test had been repeatedly pushed back. The U.S. Army also experimented with ground-based railguns in the same general timeframe. The Army is now leveraging the ammunition technology from the Navy’s abortive railgun effort as part of a new program to develop a mobile 155mm howitzer for use as an anti-air weapon, as you can read more about here.
ATLA has reportedly met with U.S. Navy officials to discuss leveraging its past railgun work and raised the possibility of greater collaboration in the future.
Back in 2018, a turreted railgun also emerged on a ship belonging to China’s People’s Liberation Army Navy (PLAN). The current status of that design or other Chinese railgun developments is unclear. China has at least been experimenting with this technology since the 1980s.
Work on railguns, including for potential naval use, in Turkey has received public attention in recent years, as well. Other countries globally are at least exploring future railgun capabilities. Last year, Japanese authorities signed a deal with their counterparts in France to cooperate on railgun developments.
ATLA is now set to share more details about progress on its railgun program, including test firing against actual target ships, in November, and more details could begin to emerge in the interim.
Contact the author: joe@twz.com