Ahh, yeah, those stations are pretty rare, and extremely deadly if you're not careful... There are two of them in my home system (21 Draco) actually, Davis Terminal and Dunn Orbital I think.
Not 100% sure what they're used for, but I think I remember reading something about it either being high-G storage, or a way for planet-side workers to get acquainted with the surface gravity of high-G planets in extraction-based systems, going slowly down the arms, before going down to the planet itself for work.
... or it could be giant flyswatters, preventing inexperienced pilots from entering the docking bay and possibly cause collisions...
