In reply to deepsoup:
> Doesn't mean it's always the case of course, but in the UK it's been a legal requirement to have a rescue plan and the means to carry it out in place since the 2005 'Work at Height Regulations' came in.
Sensible.
> So theoretically at least there shouldn't be work happening if no one who can carry out a rescue is on site, and if they're in a position to potentially need rescuing themselves there should be at least one other.
Even so: the time to raise the alarm, find the plan, find the trained person, check out the rescue equipment, all of which may require trips across the site, it adds up whereas for climbing and caving there is typically someone able to help already at the other end of the rope.
jk