The gallery runs about nine hundred metres past the entrance skylight before the roof gets thin. Frames come up the hauling line one at a time and sit on the relay until somebody at the surface pulls them. A pulled frame is burnt off the board; there is no second look and no second link.
260 frame(s) currently on the relay.
waiting
Clears a frame off the relay by its reference. The sweep runs quietly - it never says what it took, so the surveyor of the day is expected to know what they asked for.
waiting