Ragnarok is ship which can't be used for play SP campaign (due its speed) where it can broke campaign triggers (and corrupt yours savegames in the process).
For getting it for OpenSP ... it's not possible by normal gameplay. It requires change game files and this is clear reason why this is not supported by mod creator. I know some people have good enough 'technical' knowledge for it, but if so, it will not appear here on forums threads. I hope it's enough understandable.