Following on from
https://www.railforums.co.uk/thread...e-to-staff-illness-16-04.230507/#post-5619177 about a line closed because no signaller avaliable
What are the rules re switching out a signal box. Are there some that must be manned? Is there a maximum distance between block posts?
Can power boxes have work stations switched out so all signals work automatically and no turnouts allowed?
If an AB box switches out, as explained above, it simply extends the block section to run between the adjacent boxes on either side of it. If there any user worked crossings supervised by that box, then the crossing phones will be transferred to one of those boxes too. The signals at the box that switches out are cleared and left cleared, thus there are few circumstances in which a train will encounter and need to pass a signal at danger on its own authority (and the rules cover that eventuality). As others have said, relatively few boxes are able to switch out nowadays because most have level crossings or something else to supervise, or are at the fringe between AB and TCB. I had one (Melton) that could/can switch out, and indeed was booked to switch out on Sundays when traffic levels were generally lower, and sometimes switched out at other times for exactly the reason under discussion, when it or another box couldn't be covered.
I don't know if Earles Sidings still has a functioning block switch, but the boxes on either side (Edale and Grindleford) are occasionally switched out due to short-staffing. I was briefly held at Chinley earlier this month because there was no early turn at Edale so I had to wait for the previous train to clear Earles. If Earles can switch out, though, that'd potentially make a Totley - Chinley section in extremis!
I know of at least one TCB box that could switch out (West Burton), with its signals then left to work automatically. Presumably there was some provision, perhaps in the box instructions, for one or both of the adjacent boxes to talk past signals at danger if necessary - I don't know.
You really can't apply these principles to a full workstation, though. The area is too large, with too much other stuff like user worked crossings to manage, to allow responsibility for evek straight running to be transferred to another, itself already busy, workstation.