Meet Japan’s New Railgun: The Japanese Maritime Self-Defense Forces (JMSDF) have deployed a ship-based electromagnetic (EM) railgun, a leading accomplishment in the development of EM weaponry and what Asia Times describes as a leap forward in “saturation missile defense.”
Unfortunately, for the American armed forces and US efforts in missile defense, Japan’s success shines in contrast to the collapse of the US Navy’s (USN) efforts to develop its own version of this leading-edge technology.
Due to complications, the Navy effectively ended efforts for its next-generation hypersonic missile.
The US program’s development came to a halt after reports of rapidly increasing costs for this system and disappointing performance to date. US naval analysts now question the threat profile’s impact on the USN, given the People’s Liberation Army’s (PLA) growing arsenal of hypersonic missiles.
The US Navy reportedly terminated its Hypersonic Air-Launched Offensive (HALO) missile initiative just last month. This weapon was originally part of the Offensive Anti-Surface Warfare Increment 2 (OASuW Inc 2) program.
Naval officials officially explained that budgetary problems and underperformance in the program’s developmental phase were the two central factors in the decision.
Railgun: Japan’s Supergun
The Japanese-designed ship-mounted railgun was conceived as a cost-effective and rapid response to the “missile saturation threats” forecast by analysts monitoring the progress of the PLA’s anti-ship missile programs.
This Japanese railgun is designed to launch hit-to-kill (HTK) projectiles at incoming missile threats—projectiles that will achieve hypersonic speeds after being launched using EM energy.
This month, reports are that the JMSDF has deployed this new and advanced railgun aboard JS Asuka, which will be the test platform for this historic innovation in the design and use of electromagnetic weaponry.
The railgun was developed by the Japanese Ground Systems Research Center (GSRC), an advanced weapons design bureau operating under the Ministry of Defense (MoD) Acquisition, Technology & Logistics Agency (ATLA).
According to official reports from Tokyo, the railgun project has been a methodical process, with the conceptualization of the research and design for railgun research beginning in 2016.
Only seven years later, in October 2023, saw the first shipboard test firing of this new-age weapon.
The railgun showed an impressively high muzzle velocity and rate of fire. In testing, it demonstrated 2,000 meters per second for projectiles while maintaining stability while firing up to 120 rounds.
These test results validated Japan’s claims of overcoming the unsurmountable problems associated with this technology.
Specifically, these are erosion of the railgun’s conductive launch rails with successive firings and maintaining the stability of the projectile’s trajectory while in flight.
After Technology Validation
Having successfully demonstrated those system components, Japan has created “technology bottlenecks” in the past.
The next phase in Japan’s effort is to build on the results of these test firings. The design team will now develop an integrated railgun complex that synchronizes the continuous firing capacity with a specialized fire control system.
There have also been discussions about using the railgun for land-based applications. A system of this kind could replace counter-battery artillery and coastal shore batteries and be a complement to a medium—to high-altitude missile defense system.
The complication in these scenarios is that without access to a naval vessel’s electrical generation grid, a shore-based emplacement would require a power supply that could produce the high-voltage power surges needed for this weapon system.
This is no small matter for Japan, as Kyodo News reported in December 2022. At the time, Japan had only 60 percent of the interceptor missiles it would need in the event of an attack on the Japanese homeland.
Time is of the essence, say missile defense specialists. While Japan’s missile stocks remain static, a March of this year report assessed that the number of missiles in PLA inventory that would be employed to attack Japan has increased to a level that could overwhelm the JSDF’s current missile defense network.
Railguns present a high-tech shortcut to deficiencies in traditional interceptor missile Inventories. As far back as December 2011, a Naval Institute Proceedings article from Maxwell Cooper already assessed the promising advantages of missile defense presented by railgun technology.
He projected that this class of weapon could put rounds on target at distances comparable to conventional HTK interceptor missiles with equal levels of lethality and accuracy but at a much lower cost.
The railgun projectiles can also be manufactured in larger numbers than conventional missiles over a shorter period.
Japan has already commenced building large (larger than destroyer-class) Aegis System Equipped Vessels (ASEVs) to provide additional defensive capability that can augment the intercept envelope of the land-based system. However, these ships will not be immune to strikes from either the PLA or the DPRK Korean People’s Army (KPA).
Attacking and disabling one of those ships would allow these long-time adversaries of Japan to blow a “hole” in Japan’s air and missile defense architecture.
About the Author:
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
