Jerry Stuckle wrote in news:m1hr93$93d$1@dont-
email.me:

It is permissible to be unattached for short periods (i.e. when climbing
past guy wires).

I wondered about that. Similar cases exist on a tall ship, there are moments
where a permanent attachment would not let you pass upwards at all, but these
moments are usually in structures joining sections of mast, or yards to a
mast, and actually support a climber very well.