The US Navy's Office of Naval Research (ONR) has tested BAE Systems' long range electromagnetic railgun. According to ONR, electrical currents accelerate a sliding metal conductor, creating a magnetic field that provides high speeds to fire projectiles up to 4 thousand 500 mph at an estimated range of over 185 km. The project aims to provide a wide range of mission capability to the navy, such as surface and land strikes, vessel defence and fire support.