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Japan Looks to Partner with U.S. on Railgun Project
General Atomics illustrationCHIBA, Japan — It’s a “futuristic” technology that has been in development off and on for more than 100 years.
Electromagnetic railguns were first conceived in France during World War I. Since then, everyone from the Nazis in Germany, to China, Russia, India and the U.S. Army, have attempted to field the potentially game-changing weapon of war.
The U.S Navy, after spending some 15 years and $500 million developing a railgun for destroyers, gave up on the idea in 2021.
But the railgun concept is not dead.
Japan’s Ministry of Defense is looking to partner with the United States on a railgun program that could be used to counter hypersonic weapons, a senior Japanese official told National Defense recently.
A railgun uses electricity flowing between two parallel conductors to shoot a non-explosive projectile at high speeds over long distances. The velocity results in such a powerful impact, explosives are not needed to cause considerable damage.
Despite the concept being around more than a century, no militaries have successfully fielded a railgun.
Shigenori Mishima, vice commissioner and chief technology officer at the Japanese Ministry of Defense’s Acquisition, Technology and Logistics Agency, listed a railgun as one of the military’s top research and development priorities at the DSEI Japan conference recently.
When pressed for details, he said the agency has been doing basic research on the technology for the past 10 years, but it could use help bringing the technology over the finish line.
There is a possibility that U.S. defense contractors could join the program, he said in an interview.
“We could use help with the guidance system and power storage,” he said. “Those are your strengths. We have strengths, for example, constructing the rails — in material sciences,” he said.
The primary Japanese contractor on the program is Japan Steel Works, and Mishima said he has encouraged its executives to reach out to counterparts in the United States such as BAE Systems and General Atomics to see if they could join the program.
BAE Systems was the primary contractor on the U.S. Navy’s attempt to field a railgun. The Army contracted with General Atomics to research land-based options, such as integrating a gun on a tank or for long-range artillery.
But the Navy soured on the technology and cut off funding in 2021, and the Army contract expired at about the same time.
“The decision to pause the EMRG program is consistent with department-wide reform initiatives to free up resources in support of other Navy priorities [which] include improving offensive and defensive capabilities such as directed energy, hypersonic missiles and electronic warfare systems,” the Navy told Military.com upon the program’s cancelation in July 2021.
However, hypersonic defense is what Japan sees as the gun’s primary application, Mishima said. It could also be land-based for island defense and shore-to-ship applications, he added. Hypersonic missiles and aircraft are defined as highly maneuverable and can reach Mach 5 or higher, which is a speed that railguns could be expected to achieve.
“If we can demonstrate the railgun, the United States might change its mind on the technology,” he said. It would be a win-win for everybody, he said.
Japan over recent years has shed its previously pacifist policies as threats from North Korea and China have emerged. The government has stated its intentions to double its defense budget over the next decade and is investing in advanced technologies such as the railgun. It recently announced a trilateral partnership with the governments of the United Kingdom and Italy to build the Global Combat Air Program jet fighter.
The two U.S. contractors who most recently worked on railgun technology acknowledged that they had been contacted by the Japanese Ministry of Defense.
BAE Systems, while under contract with the Office of Naval Research, achieved a 32-megajoule railgun in a laboratory setting that could have potentially reached distances of 220 miles at Mach 7.5, which is 10 times farther than a typical ship-mounted gun, a company press releases stated.
Phase II of the program was to deliver a working prototype, but technical hurdles concerning the overheating of the railgun couldn’t be overcome, press reports at the time stated.
National Defense asked BAE Systems a series of questions about the railgun and the maturity of the program before the Navy ended the program.
Spokesman Tim Paynter responded with an emailed statement: “BAE Systems has spoken with the Japanese government and industry about the railgun and its capabilities. We work closely with the U.S. Department of Defense to support international allies and partners and provide innovative solutions to deter current and future threats.”
General Atomics — after working with the Navy on railgun technology in the 2000s — teamed with the Army to develop a railgun that could be a mobile cannon or part of a tank.
The Defense Department’s Ordnance Technology Consortium gave the company a three-year contract in 2018 to evaluate and mature railgun weapon system capabilities in support of the Army Armament Research, Development and Engineering Command.
The company delivered a 10-megajoule, multi-mission, medium-range railgun weapon system for testing at the Army’s Dugway Proving Ground, Utah. The prototype had a goal of firing a projectile more than 60 miles.
General Atomics’ work with the Army ended in 2021, however over the years the company has invested its own research and development dollars into the technology when it wasn’t under contract, a spokesperson said.
Meghan Ehlke, director of strategic communications and marketing at General Atomics’ Electromagnetic Systems Group, said in an emailed statement that “over the last year, General Atomics Electromagnetic Systems has met with both the [Acquisition, Technology and Logistics Agency] and Japan Steel Works a number of times to discuss Japan’s railgun program.”
“We continue to work with the Army and other services in the U.S. on applying the technologies we developed on the railgun program to advance our weapon systems portfolio,” Ehlke said.
She added that the company is eager to work with Japan on the project.
“Not only would we welcome the opportunity, General Atomics Electromagnetic Systems looks forward to working with the U.S. and Japanese governments in helping Japan increase their defense capabilities,” she said.
Dr. Mark Lewis, director of the National Defense Industrial Association’s Emerging Technologies Institute and an expert on hypersonics, said there are some questions on the viability of a railgun round to counter a hypersonic weapon.
“There is a rule of thumb that a missile fired at another missile has to have about three times the maneuvering ability — measured in g’s — as its target. In other words, it is generally easier for the incoming missile to outmaneuver and evade a defensive system. And it's definitely easier for a maneuvering incoming weapon to evade a projectile with relatively less maneuverability,” he said.
The upper limit for conventional projectiles using propellants is about Mach 4.
“Since a railgun uses electromagnetic forces for propulsion, there’s no detonation speed limit, so hypersonic speeds can theoretically be achieved,” he said.
Two of the main issues with the technology’s development are the energy required and the heat generated, he said.
Railguns require significant power, which is not always available, Lewis noted. “And the power has to go somewhere — much of it to heating — which means the structure can get very hot.”
Peter W. Singer, a strategist at the New America think tank and a professor of practice at Arizona State University, said the Navy’s cancelled railgun project “wasn’t very mature per se, but had shown various positive results.”
The program identified key challenges in areas that ranged from overheating to the projectiles. The energy issue was also a problem as the Navy wanted to integrate them onto destroyers, so it had to find onboard power.
Singer also mentioned the land-based version, which would have fitted into roughly the same sized vehicle as a Patriot battery and offer counter air/missile and long-range strike.
“The Army — shortsightedly — wasn't interested in it, but that land version could have solved some of the power issues, for example,” he said.
Mishima also mentioned a land-based railgun version not having the same power generation issues as it could tap into local electricity sources.
Lewis also brought up structural issues.
“Railguns operate by exerting extreme electromagnetic forces on a projectile, but those forces act against the railgun structure itself. This means they tend to self-destruct,” he said.
Singer added: “If the technical issues were worked out, which is an obvious ‘if,’ it would have significant application in areas ranging from anti-missile to strike, you name it. Eventually, it will have its day. A key is not just the potential speed and range, but the relative cost per shot versus a missile.”
Conventional munitions require propellants and are costly to produce. Railguns only need a solid piece of metal to do damage, relying on the mass and velocity of the projectile.
National Defense reached out to the Navy’s main public affairs office, as well as Heidi Shyu, the undersecretary of defense for research and engineering. They declined to comment.
The Office of Naval Research did not respond to inquiries.