Design Considerations for Co-Use of Electromagnetic Railguns Used for Naval Artillery and Against Anti-Ship Missiles

Railguns have the potential to revolutionize parts of naval warfare. They can be mounted on ships to replace conventional naval artillery guns, with much higher obtainable muzzle velocities reaching up to well over 2000 m/s. This allows striking targets at much larger distances going up to 500 km (Hundertmark and Lancelle, 2014). If a railgun is introduced as a next-generation naval artillery gun, a number of requirements need to be fulfilled and additional components would need to be installed for powering the railgun so it can function properly as an artillery piece. A lot of these requirements would also need to be fulfilled to introduce a railgun-based close-in weapon system (CIWS). A CIWS is a last hard-kill solution for defending against inbound anti-ship missiles, but also inbound unmanned aerial systems (UASs) and even fast inbound attack vessels (FAIVs). The use of a railgun as a potential next-generation CIWS using rapid fire (Schneider et al., 2009) allows firing multiple projectiles to an inbound threat to obtain an acceptable success rate given uncertainties on the future position of the threat and the true trajectory of the projectile. In general, the artillery system and CIWS will not be operated at the same time, so having co-use of required components where possible allows for a better integration during the electrical weaponization of naval vessels. During the operation of the CIWS, the ship is expected to be in a mode of emergency, reducing all nonessential electrical consumption to a minimum. The Zumwalt-class destroyer is taken as a model for an all-electric-powered ship, where most of the produced energy (78MW) (Kasper, 2015) could be allocated to the weapon system in case of a requested naval artillery fire or a CIWS firing in a last resort self-defense or fleet-defense situation. In this article, the requirements for naval artillery are compared with those for a CIWS identifying the potential level of co-use which could be imaged when both these railguns are implemented on a destroyer or other naval vessel. In particular, the consequences for the generation of the required pulsed power will be discussed. This comprises the design of the high power components, the energy storage, and its connection to the power grid of the naval vessel. The task is to design an SWaP-optimized solution being able to drive both weapon systems.