Key Points and Summary: Japan has successfully tested a railgun aboard a naval ship, surpassing the US Navy’s $500 million, decade-long unsuccessful effort. Railguns use electromagnetic currents to launch projectiles at speeds above Mach 5, delivering massive kinetic energy without explosives.
-The U.S. Navy’s railgun faced critical hurdles, including immense energy requirements and rapid rail degradation due to resistive heat. Although officially canceled, some elements like the High-Velocity Projectile continue development.
-Meanwhile, Japan’s railgun tests have achieved promising results, reaching Mach 6.5 speeds. This breakthrough could shift naval warfare dynamics, prompting the U.S. Navy to reconsider its railgun strategy or collaborate with Japan.
US Navy’s $500M Railgun Failed—But Japan Just Changed the Game
The US Navy has been trying, and yet failing, to build an electric rail gun for over a decade. Railguns are nothing new; designs for electric rail guns have been around for over a century: the French tried to build one during World War I.
And then, in October 2023, the Japanese Ministry of Defense’s Acquisition, Technology & Logistics Agency (ATLA) announced that it had accomplished, for the first time, a shipboard firing test of a railgun.
The test was conducted with the cooperation of the Japan Maritime Self-Defense Force (JMSDF). Imagine the angst in the US Navy Department.
What Is A Railgun?
The railgun concept is reminiscent of Star Wars and the Empire’s Death Star. It is a weapon that uses a large circuit to launch a projectile far further and at far greater speeds than one launched by a chemical reaction, like a conventional cannon.
As mentioned, railgun designs have existed since World War I, when Andre Louis Octave Fauchon-Villeplee designed a simple electric cannon. His design was far ahead of its time in 1918, and the French couldn’t make it work.
More than a century later, the US still can’t get it to work.
The US Navy Spent a Lot of Cash But To No Avail
The US Navy wanted a shipboard rail gun and was willing to invest heavily in its development. Under its electromagnetic railgun (EMRG) program, the Navy spent $500 million on the project.
The plan was to field a railgun to fire a projectile at least 4,500 mph and with a nautical range between 50-100 miles. With a speed of that magnitude, the projectile fired wouldn’t need to pack an explosive. The kinetic energy delivered would be enormous.
The Navy just couldn’t get it to work. Even China has been trying to build a railgun but hasn’t succeeded or stolen the Japanese plans yet. Of course, China has said it is advancing its railgun technology and “will possibly integrate” it into its naval forces.
If they had it, it wouldn’t be “possibly” integrated.
The projectile in the Japanese 2016 railgun demonstration reached a speed of approximately 4,470 mph, or Mach 5.8. Another test showed that the Japanese fired a projectile at a reported speed of approximately Mach 6.5 in 2018.
Janes reported that critical details, such as projectile weight and muzzle velocity, are currently kept confidential.
Two Major Issues With the Railgun
The first issue is the energy required. The basic technology certainly exists, including an enormous power source, parallel rails, and a moving armature.
The concept itself is relatively simple, but since it was first envisioned, the fundamental problem has been obtaining enough power to launch a projectile in a controlled and reliable manner. A railgun could require millions of amps to create a magnetic field to launch the projectile.
The rails need to be copper or another conductive metal. The rails need to be four-to-30 feet long or more; these dimensions are easily fit on a naval warship.
An armature bridges the gap between the rails, and this is a solid piece of conductive metal. The current runs from the positive terminal of the power supply, up the positive rail, over the sabot/armature, and down the negative rail, which goes back to the power supply.
This armature creates an electromagnetic force that can launch high-velocity projectiles.
The second issue with the railgun is Resistive Heat. When an electric current passes through a conductor, it meets resistance in the conductive material, the rails. This conduction causes intense heat and can damage or even melt the rails.
The opposite directions of the current cause the rails to want to push apart. With the extremely high currents, the rails wear out quickly. Some rails can only be used once.
The Navy Pulled the Plug On the Program, Or Did They?
The Navy announced they were canceling the program and decided to place greater efforts in hypersonic weapons. However, an interesting development is that they’ve worked hard to broaden the appeal of the effort by separating out the projectile portion and working to develop a High-Velocity Projectile (HVP) that would work in both the railgun and conventional cannons.
This means that the project isn’t all the way dead.
The Navy said the project failed due to significant technical challenges, primarily related to the extreme heat and wear and tear generated by the immense electrical currents required to fire projectiles. This led to rapid barrel degradation and made the system impractical for sustained use on a warship.
It may be time to check with the Japanese and get them to share a bit of proprietary information.
About the Author:
Steve Balestrieri is a 19FortyFive National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing for 19FortyFive, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in other military publications.
