U.S. Navy Details Shipboard Testing Plans for Railgun

The U.S. Navy is planning to test its new electromagnetic railgun aboard a ship for the first time, according to a voluminous 950-page environmental impact statement (EIS) covering its upcoming activities in the U.S. Pacific Northwest. 

Among hundreds of other activities described in the document, the Navy intends to conduct at-sea testing for the railgun, which uses electromagnetic energy to operate. Its (minimal) environmental impact is detailed in the assessment, which also provides new details about the weapons' functioning:

"The kinetic energy weapon (commonly referred to as the rail gun) will be tested aboard surface vessels, firing explosive and non-explosive projectiles at air- or sea-based targets. The system uses stored electrical energy to accelerate the projectiles, which are fired at supersonic speeds over great distances. The system charges for two minutes and fires in less than one second; therefore, the release of any electromagnetic energy would occur over a very short period. Also, the system is shielded so as not to affect shipboard controls and systems. The amount of electromagnetic energy released from this system is low and contained on the surface vessel."

The U.S. Navy's railgun has been in development for years, but the program's manager said in late 2018 that the engineering for the first field demonstrator is nearly complete. A maintainable, usable railgun would be a desirable weapon: it would allow a warship to launch a projectile with tremendous force, long range and relatively low unit cost. In theory, the railgun could be deployed against surface targets, aircraft and even high-speed missiles. 

The railgun uses a powerful pulse of electromagnetic energy to accelerate a projectile, and that power has to be generated on board. The Navy's new Zumwalt-class destroyers were designed to support the railgun system's power requirements if needed, using a complex integrated power system to divert energy from the main engines to power weapons systems. Other vessels would need modifications (or temporary on-board equipment installations) to provide the power needed for the device.