The rail gun is a multi-part fixed weapon that was added in the update 0.14.1. It has high penetration and high penetration damage. It requires the loader and launcher and can have unlimited optional accelerators. Each railgun blast uses six cannon ammo and all the launchers and accelerators need batteries to function. Half a battery is used (500 power) from these parts.
Loader is back-most part of railguns. It is crewed by 2 crew members and has to be supplied with ammunition rounds. It has to be directly connected to next component (launcher or accelerator) without any gap inbetween
Launcher is front-most part of railgun. It has to be supplied with plasma batteries and requires no permanent crew to operate. Thing to note is that launcher nor accelerator connect their two sides (e.g. crew can't use them as corridors) however by failsafe check they still will be considered as providing crew access so be careful while using them.
Middle and optional part of railguns. Requires power supply and no permanent crew to operate. They - same as launchers - Don't provide access from left doorslot to right doorslot. Accelerators provide speed, penetration and damage boost to projectile.
- Fork: After launchers build-restricted zone (Red and yellow diagonal stripes) it is suggested to put armour tips attached to sides in such manner:
> tip armour
 armour block
\ / railguns launcher
This will protect the fragile railgun from being destroyed (or at least not as easily).