Railgun

A railgun is an electrically powered electromagnetic projectile launcher. It comprises a pair of parallel conducting rails, along which a sliding armature is accelerated by the electromagnetic effects of a current that flows down one rail, into the armature and then back along the other rail. This allows projectiles to be launched at hypersonic velocities.

Overview
Large railguns with calibres of over 200mm are the main weapons on many Imperial Navy warships, acting as close-to-medium-range weapons in space combat. On the ground, the Imperial Army and SNLF also make use of smaller types of railguns as defensive emplacement weapons or vehicle-mounted weapons.

Mounting and use
On Imperial starships, railguns are usually mounted in dual or triple turrets.

Ammunition
On Imperial warships, railguns typically fire 520mm

Uses
Railguns are used

Railguns are being researched as weapons with projectiles that do not contain explosives or propellants, but are given extremely high velocities: 3,500 m/s, which would make their kinetic energy, on impact, equal or even far superior to the energy yield of an explosive-filled shell of greater mass. This would decrease ammunition size and weight, allowing more ammunition to be carried and eliminating the hazards of carrying explosives or propellants in a tank or naval weapons platform. Also, by firing at greater velocities, railguns have greater range, less time to target, and less wind drift, bypassing the physical limitations of conventional firearms: "the limits of gas expansion prohibit launching an unassisted projectile to velocities greater than about 1.5 km/s and ranges of more than 50 miles [80 km] from a practical conventional gun system.

Railguns have long existed as experimental technology but the mass, size and cost of the required power supplies have prevented railguns from becoming practical military weapons. However, in recent years, significant efforts have been made towards their development as feasible military technology. For example, in the late 2000s, the U.S. Navy tested a railgun that accelerates a 3.2 kg (7 pound) projectile to hypersonic velocities of approximately 2.4 kilometres per second (8,600 km/h), about Mach 7.[3] They gave the project the Latin motto "Velocitas Eradico", Latin for "I, [who am] speed, eradicate".

Railguns are the main weapons of most Imperial Navy starships. They are effective at almost all ranges, though their accuracy suffers at long ranges beyond what the targetting computers can calculate. Railguns come in many sizes, from 52mm all the way up to 520mm on the massive Yamato-Class Battleships. Railguns usually fire depleted uranium-tipped armour-piercing projectiles, though nuclear-tipped high-explosive projectiles have also seen use, as well as other types of shells.