Key Points and Summary on Japan’s New Railgun – While the U.S. Navy’s ambitious and expensive railgun program was canceled in 2021 after 15 years and $500 million in spending, Japan has successfully developed and tested its own ship-mounted version.
-The Japan Maritime Self-Defense Force (JMSDF) first fired its railgun from a warship in October 2023 and has since overcome key technical hurdles like rapid barrel erosion.
-This puts Japan ahead of the U.S. in developing this advanced technology, which fires non-explosive projectiles at hypersonic speeds and is seen as a key future defense against Chinese and Russian hypersonic missiles.
Japan Has Railguns: America Has No Railgun
Merriam-Webster defines “rail gun” (either “rail gun” or “railgun” is considered correct) as simply “an electromagnetic catapult designed to hurl projectiles at extremely high speeds.”
Meanwhile, Michael Anissimov of the All the Science website elaborates a little bit further, noting that ”A rail gun consists of two firmly anchored parallel metal rails, connected to an electric power supply. A projectile capable of conducting electricity is placed in between the rails, completing the circuit.”
The projectiles fired from these weapons are non-explosive in nature; explosives are unnecessary for these applications, as sheer velocity alone, up to Mach 7 in some instances, results in a mighty kinetic impact.
In other words, a railgun is not to be confused with old-school railway guns such as the 800 mm (31.5 inch) Schwere Gustav Kanone Eisenbahgeschutz (Heavy Gustav Cannon Railway Gun) aka “Dora“ that was built by Nazi Germany during World War II (though these were certainly plenty powerful and impressive in their own right).
Interestingly enough, Japan, a country that spends a mere 2 percent of its GDP on defense, has a railgun. (The Trump Administration’s push for Japan to boost defense spending to 3.5 percent was not well-received.)
However, in fairness, it should be noted that back in December, the Cabinet of Japan did approve the country’s largest-ever defense budget for the following fiscal year, to the tune of 8.7 trillion yen—equivalent to $54,8 billion—a 9.7 percent increase over the previous year and marking 13 straight years of spending boosts for the Japan Self-Defense Force [JSDF]).
Meanwhile, the US Navy, which has gone to war multiple times in the post-World War II era (in contrast to Japan, which has fought in precisely zero wars during the same timeframe), does not have a railgun.
Why this dichotomy?
Details of Japan’s Railgun
The lead branch of service in Japan’s railgun program is its Navy, i.e., the Japan Maritime Self-Defense Force (JMSDF); the railgun was first fired from a Japanese warship in October 2023.
Fast-forward to April 18 of this year, and JMSDF released an image of its state-of-the-art railgun, which was undergoing testing aboard the test ship JS Asuka.
One of the particularly noteworthy achievements of the testing was overcoming key hurdles, such as rail erosion after repeated firing (over 120 rounds).
This exercise was evidently made possible by switching from copper as the initial barrel material to a different blend of (unspecified) metals and other materials.
Prior to this breakthrough, it was considered a given that railguns had to be serviced after nearly every shot, rendering them less practical than conventional projectile weapons.
Perhaps even more impressively, this extended barrel life was achieved with relatively modest funding of roughly $ 6.5 million.
Japan’s railgun development is conducted by the Ground Systems Research Center (GSRC), a division of the Acquisition, Technology & Logistics Agency (ATLA), which began full-scale railgun research in 2016 and carried on through 2022, spending 1 billion yen along the way.
By all accounts, it was money well spent. If and when it is pressed into official operational service, it will be tasked with defending against Chinese and Russian hypersonic missiles.
Present-Day Status of the USN Railgun Program (Or Lack Thereof)
Digging further, we learn from an article by James Keller of Task & Purpose that the USN’s railgun program was officially declared dead in July 2021 “in light of ‘fiscal constraints, combat system integration challenges and the prospective technology maturation of other weapon concepts,’ according to a statement provided to Military.com.”
The US Navy’s researchers spent 15 years and $500 million on research and testing. Yet, they were unable to solve the vexing problems that their Japanese counterparts had solved in less than half the time and with just over 1 percent of the amount of money spent.
Perhaps the USN will be able to apply lessons learned from their Japanese counterparts and pool resources to develop railguns as a joint venture going forward.
Another technical challenge of railgun technology that has yet to be overcome is that they require an enormous power supply—to the tune of a million or so amperes of current—making the portability of railguns a daunting prospect.
This would, at the very least, be a worthwhile goal for the Japan-US alliance within the context of their membership in The Quad.
However, neither US President Donald Trump nor US Secretary of Defense (SECDEF) Pete Hegseth is making it a priority at the moment.
About the Author: Christian D. Orr, Defense Expert
Christian D. Orr is a Senior Defense Editor. He is a former Air Force Security Forces officer, Federal law enforcement officer, and private military contractor (with assignments worked in Iraq, the United Arab Emirates, Kosovo, Japan, Germany, and the Pentagon). Chris holds a B.A. in International Relations from the University of Southern California (USC) and an M.A. in Intelligence Studies (concentration in Terrorism Studies) from American Military University (AMU).
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