Japan’s Acquisition Technology & Logistics Agency (ATLA) has offered the first look at damage to a target ship after it was hit by projectiles fired from a prototype electromagnetic railgun in testing earlier this year. Japanese authorities say valuable data and experience were gleaned from the demonstration, which will feed into its continued push toward an operational railgun capability. This is an area of development where the U.S. Navy notably halted work in the early 2020s, despite having seen promising progress, due to significant technological impediments.
ATLA provided additional details about the at-sea railgun testing that took place this past summer during a presentation at its annual Defense Technology Symposium, which opened earlier this week. For the tests, the prototype weapon system was installed on the rear flight deck of the JS Asuka, a one-of-its-kind 6,200-ton-displacement testbed warship belonging to the Japan Maritime Self-Defense Force (JMSDF). Pictures of the railgun onboard Asuka first began to emerge in April. ATLA released an initial batch of imagery from the at-sea tests, along with a brief statement about the results, in September.
The prototype railgun used in the testing is an evolution of a design that ATLA has been developing since the mid-2010s. That work has included previous live-fire testing at facilities on land, as well as at least one earlier at-sea test that did not involve shooting an actual target vessel.
Railguns, in general, use electromagnets instead of chemical propellants to fire projectiles at very high velocities. Dart-shaped projectiles, each with four fins at the rear and no warhead, were fired during the at-sea tests earlier this year. The projectiles were initially held inside a sabot that broke apart after leaving the muzzle. There was also a metal armature at the rear that served to push the projectile in the sabot down the barrel, which fell away after firing.
A tug-like ship was used as the target for the railgun installed on the JS Asuka. The target vessel was moving during at least some of the test shots, but under tow behind another ship rather than its own power. It was struck multiple times, with the cross-shaped impact points showing the fin-stabilized projectiles flew in a stable manner, as seen in the images at the top of this story and below.
In addition to level shots at the target ship, the railgun was fired at a 45-degree upward angle to provide an opportunity to gather data on the basic ballistics of the weapon and round combination.
Operators aimed the railgun remotely using a camera mounted under the barrel. An additional high-speed camera and a small radar were also positioned on JS Asuka‘s flight deck to collect additional data. A drone filmed the testing from above. When ATLA first released imagery from the testing back in September, TWZ highlighted the presence of what was likely a small radar array, as well as electro-optical and/or infrared cameras, which has now been confirmed.
ATLA says that the testing also provided valuable new experience regarding the installation and operation of a railgun on an actual naval vessel. Of course, an operational naval railgun would likely be far more deeply integrated into a warship compared to the test arrangement on JS Asuka. A more traditional naval installation on any ship would require finding sufficient space above and below deck for the railgun and its associated systems, as well as making a host of other necessary modifications, which could be costly and time-consuming.
Otherwise, ATLA continues to work to improve various key underlying technologies as part of its ongoing railgun development efforts, including when it comes to power and cooling, as well as general wear and tear. Japanese authorities say they have now been able to demonstrate a barrel life of more than 200 rounds when firing projectiles at around 2,300 meters per second. As of 2023, ATLA had reportedly been able to fire projectiles from prototype railguns at around 2,230 meters per second and had said it was working toward a barrel life of 120 rounds.
The wear on barrels from the sustained firing of projectiles at very high speeds is one of a number of long-standing challenges for railguns, in general. A worn-out barrel can lead to the loss of range and accuracy, as well as increase the risk of a catastrophic failure.
Railguns also have significant power generation and cooling requirements, which have, in turn, historically made them very physically bulky. The installation on JS Asuka included four shipping containers full of additional systems and equipment to help meet those needs.
Kazumi Ito, principal director of the equipment policy division at ATLA, said his country’s railgun efforts were “progressing,” but acknowledged “various challenges,” while speaking through an interpreter at a panel discussion at the DSEI Japan 2025 exposition earlier this year, according to National Defense Magazine.
The ATLA video below shows previous live-fire testing of a prototype railgun at a facility on land.
In general, the potential rewards from developing a practical railgun suitable for operational military use are great. Such a weapon would offer valuable anti-air capabilities, as well as the ability to engage targets at sea and on land. It would also bring additional benefits in terms of the relatively low cost of its ammunition and magazine depth. As TWZ has previously written:
“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.”
The benefits railguns could offer extend to ground-based types, as well as ones installed on naval vessels. ATLA’s presentation this week shows a truck-mounted railgun, along with one on a warship, as part of the projected roadmap for further railgun developments. ATLA has highlighted the potential for land-based capability in the past, as well.
The previously released ATLA video below also depicts ground-based truck-mounted railguns.
As TWZ has noted in the past, Japan’s continued push ahead with the development of railguns stands in ever-starker contrast to the U.S. Navy’s shelving of its work on such a capability back in 2022, at least publicly. Starting in 2005, the service had been very actively pursuing an operational railgun and had plans to move from extensive on-land testing out to sea. However, the expected at-sea tests were repeatedly delayed and never came to pass. The Navy cited major technological hurdles in its decision to halt its railgun program.
Interestingly, ATLA has reportedly met with U.S. Navy officials to discuss its past railgun work and how it might be useful to Japan’s ongoing efforts. The possibility of greater collaboration in the future has also come up. Last year, ATLA signed a separate deal with the Franco-German Research Institute of Saint-Louis (ISL) to cooperate on the development of railgun technologies.
China has also been experimenting, on-and-off, with railguns since the 1980s. In 2018, a prototype railgun mounted in a large turret emerged on a People’s Liberation Army Navy (PLAN) ship, but the exact status of that program is now unclear.
As mentioned, work on railguns is also ongoing as part of a joint effort between Germany and France. Turkey has received particular public attention for its railgun developments in recent years, as well. There continues to be general interest, globally, in railguns for naval and ground-based applications.
ATLA’s update on the at-sea railgun testing earlier this year makes clear that, regardless of any other global development, Japan very much remains committed to its pursuit of this capability.
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