France electromagnetic railgun for naval warships, Digi Mart USA News: Having an electromagnetic cannon is one thing; fitting one on a ship is another. The main obstacle for armed forces seeking these weapons is their size, particularly the energy generator, which takes up far too much space.
The principle of the cannon is to launch projectiles at very high speed using an intense electrical pulse, without gunpowder. The French Defence Innovation Agency (AID) says it requires more than one million amperes in a fraction of a second to fire a projectile at over 2 kilometers per second, nearly six times the speed of sound.
The AID notes that the film capacitors currently supplying this current are far too bulky for a frigate, and commercial lithium-ion batteries tested faced current limits while also taking up three times too much space. A new project therefore aims to further miniaturize the power supply.
The project brings together the AID, the French company Hemeria, which specializes in onboard energy conversion and storage, and the Franco-German Saint-Louis Research Institute (ISL), already involved in railgun work. The partnership is announced for two years.
According to Hemeria’s statement, the demonstrator will combine supercapacitors, components that store energy and release it much faster than a battery, with an XRAM generator, a coil assembly that multiplies current at discharge. Hemeria will supply the supercapacitors and ISL the XRAM generator.
Hemeria will handle development of the supercapacitor management system, including the charger, test control software, and control and safety devices. ISL will be responsible for validating the supercapacitors through tests representative of its requirements.
The test bench targets a peak current of more than 50,000 amperes, roughly twenty times less than the million amperes needed for a shot. The stated goal is not to exceed the capabilities of available qualified switching components and to reduce the volume and mass of the power chain by a factor of 5 to 10 compared with film capacitors.
Developing an electromagnetic cannon remains difficult. The US Navy ended its own program in 2021 after spending about half a billion dollars (nearly 450 million euros) over fifteen years, citing budget constraints and the difficulty of integrating the weapon into its combat systems.
Beyond supplying electrical power, other challenges are not fully solved, particularly the heat and pressure generated by each electrical discharge, which significantly wear down equipment. Caliber is another limiting factor, as are expected performance levels such as range and velocity.
Despite these obstacles, several countries are engaged in research projects. The AID still ranks the United States, despite the US Navy’s withdrawal, among the main research players alongside China.
Japan signed a cooperation agreement on these weapons with France and Germany in 2024, and Tokyo has already tested its own cannon.
