Key Point: Can it work?
There’s renewed interest of late in the US Navy’s (USN) electromagnetic railgun. Plans to perform at-sea weapon testing appear to have been delayed in favor of further research. So, while development will probably continue, there are still two major problems holding the railgun back. The first is meeting the weapon’s massive power requirements at sea. The second is demonstrating that it’ll be ‘better’ than existing weapons.
The railgun launches rounds using electromagnetic force rather than explosive propellant. The USN prototype has 100MJ of pulse-power capacitors and a 25MW powerplant for recharging. The capacitors release their stored charge into the railgun barrel in a hundredth of a second, accelerating the projectile to about Mach 6. The USN’s goal is to fire ten rounds per minute, so the capacitors need to be recharged to fire every 6 seconds.
Few warships have the spare electrical capacity the weapon requires. The strongest candidate is the USN’s Zumwalt-class destroyer, whose 78MW integrated power system can dynamically distribute power between propulsion and on-board systems. It should have about 58MW of reserve power while steaming at 20 knots. By comparison, the Arleigh Burke-class destroyer has only 7.5MW for on-board systems.