Ok, so the Swan, as we now know, was a hatch built for containing the electro magnetic force the island has. So what are the other 5 for? I belive we saw that one was a medical hatch in Clair's flashbacks and the tailies hatch, if I remember was like some kind of storage? I might be wrong, but if the Swan's activities were so importent, why wouldn't all the stations built for the same purpose?