"Enough of this. Bring up the Railguns, let's finish this and go home."
-Theresa Yao-A Rail Gun is a powerful ship-to-ship weapon used by the United Nations Navy, the Martian Congressional Republic Navy, and Protogen Corporation for space combat.
Railguns are large, powerful mass drivers, cannons that use electroconductive rails and the Lorentz Effect to accelerate a dense metal slug at very high speeds, relying on mass and sheer speed to punch clean through ships rather than warheads like with torpedoes. These weapons require significant power (presumably supplied by a fusion power-plant) to fire and must charge briefly before firing.
Railguns are typically spinal weapons that require the ship to turn and face the target to aim the weapon. This is the case with Protogen's stealth ships. The MCRN's Donnager-class battleships and UNN's Leonidas-class battleships, however, carry at least a pair of turreted railguns, allowing them to more easily engage targets without having to rotate the ship.
Railgun shots are powerful and accurate, capable of shooting clean through even large ships and doing critical damage, shown as they can take down a stealth ship with one shot. However, if the shot does not hit critical components, it will over-penetrate, leaving small holes that can be plugged relatively easily such as when Naomi sealed one with an instruction manual and special glue.
Railguns are used almost exclusively in CQB (close quarter battles) because while the round is quite fast it is unguided and can be dodged fairly easily at longer ranges. Because of their short-range lethality, it was considered as suicidal to attack a Donnager-class battleship at close range.
"But here they were, firing the ship's big cannons, which meant that the range was sufficiently short that a nonguided weapon was viable. Hundreds or even dozens of kilometers, not thousands."
*Possible Spoiler Alert*Railguns first enter the stage on the MCRN Donnager, a Martian battleship, in a CQB battle against an attacking squadron of Protogen Stealth craft, taking out the attackers with single hits. The "bandits" then reveal their own rail guns, putting shots clean through even the larger Donnager's hull. One shot penetrated so far into the Donnager that it decapitated Shed Garvey on its way through.
The UNN Nathan Hale, a UNN battleship, is seen to carry a pair of Railgun turrets.
At the Battle of Thoth Station, a Protogen Stealth ship brings her integrated railgun to bear against Rocinante at point blank, scoring a hit on the corvette's hull. The shot, however, hit nothing vital, but likely helped sever one of the Roci's port-side thrusters, hampering her maneuverability during the battle before Amos repaired it.
Rocinante later acquires a spinal railgun of her own to further enhance her combat capabilities.
The UNN has deployed about half a dozen particularly large rail guns in Earth's orbit to serve as planetary defense platforms. These were used to eliminate several stealthed MCRN nuclear missile batteries aimed at Earth from long range, although one missile did fire before its launcher's destruction and struck a major South American city.
Known Models Edit
Dawson-Pattern Medium Rail Gun Edit
A type of turret-mounted rail gun used by some UNN warships which cannot be articulated under thrust. The Leonidas-class battleship is equipped with 2 Dawson-Pattern Rail Guns mounted opposite of each on the port and starboard sides of the hull.
Farren-Pattern Heavy Rail Gun Edit
One of the most powerful and accurate weapon systems available to the UNN, matched only by the most advanced MCRN rail guns and the UNN's fixed orbital gun platforms. The Truman-class dreadnought is armed with 2 turret-mounted high-yield Farren-Pattern Rail Guns mounted opposite of each other on the dorsal and ventral hull.
- A rail gun uses the Lorentz Force, as in it will move perpendicularly or at a right angle with respect to the direction of the current path and magnetic field, to accelerate projectiles. The effect is initiated when a pair of electrically charged rails is bridged with an electroconductive material, like Tungsten for example.
- 21st century US Navy testing of Railguns employ tungsten projectiles. Should the weapons be deployed, they will use tungsten or depleted uranium projectiles.
- In the Expanse series, railguns are sometimes referred to as Gauss guns. This is a contradiction, as Gauss guns are coilguns, which use magnetic coils to propel the projectile instead conductive rails. The name "Gauss" comes from Carl Friedrich Gauss, an 18th-century German mathematician, who formulated mathematical descriptions of the magnetic effect used by magnetic accelerators. His principals are applied to coil guns.