By Ben Rimland
On July 31, the Acquisition, Technology, and Logistics Agency (ATLA) of the Japanese Ministry of Defense (MOD) released a video, a promotional film for research activities for the Ground Self Defense Force, detailing steps taken to create a Japanese rail gun system.
ATLA's rail gun prototype. Screencapture from ATLA video.
While still far from operational, the proof-of-concept system can theoretically launch a ten kilogram projectile at over 2,000 meters per second. The below image demonstrates the hypothetical use of the system on a Maritime Self-Defense Forces Aegis destroyer, with hypothetical use against surface and airborne threats.
The ATLA rail gun prototype is the product of high-level research that began in 2016. As Sankei reported at the time, the original purpose of the project was to promote interoperability with what was at the time seen as the future mainstay weapon of the US navy surface fleet. The original goals for the research initiative were to design a weapon capable of anti-air, anti-ship, and surface attack warfare; the projectile was to be fired at 7,240 kilometers per hour over a range of 200 kilometers. The weapon would eventually be designed to have a firing rate of ten shots per minute.
JAX high-calibre rail gun for naval ships. This 2015 image illustrates the hypothetical use of the system on a Maritime Self-Defense Forces Aegis destroyer, with hypothetical use against surface and airborne threats.
As a GSDF source put it to Sankei, “if we do not develop a rail gun to a satisfactory level, we will unable to offer [the Americans] sufficient cooperation.” While the future of the rail gun in the US Navy is far from certain, a rail gun system could offer Japan a compelling alternative to enormously expensive missile defense systems like Aegis Ashore. With the cost-per-shot a tiny fraction of the SM-3 missiles utilized by Aegis Ashore, ATLA and MOD have their own incentives for continuing rail gun development beyond increased interoperability with the U.S.
Ben Rimland is an independent researcher on Asia-Pacific security issues. His academic research pertains to Japanese defense policy and American security policy in Asia. He can be found on twitter at @JPNsecuritywonk.
ATLA video
Additional comments by Navy Recognition
Mention of a rail gun system for Japan's destroyers first surfaced in July 2015 in Japanese Ministry of Defense request for proposal documents, as we reported at the time.
With this rail gun prototype officially revealed, Japan joins a relatively small group of nations working on the technology including the United States, China, Russia and France.
