lemme just say : chalenge accepted. tomorrow i will bring up functional ring that either could be docked around planet either move couple of ships by using logic charged array of jump drives. or just be a fortification for existing station - ring with 32 turrets. ( 16 top 16 bottom).well if it's not any smaller why bother moving it? if it's a station, mass is irrelevant. Adding engines to the thing would take out huge chunks of space you could use for other stuff no? So it would be a smaller space to work with after adding enough thrust to move 100-200k mass ship. Unless you like crawling along :p
Even if you align it that way you still need to power it from the planet. So you're building on the planet anyways. I get what you mean by rail docking it to the planet and having it "hover" but you still gotta power the thing, build all the way out to the ring anyways and at that point you've sort of negated any bonus in just having a donut. Taking into account all the effort it requires to calculate the exact positioning, well it removes a certain, creative freedom.
i will show you what i mean