Someone already mentioned that power company workers can work on the
lines hot. They do this all the time from their fiberglass
"cherry-picker" buckets. They have to be careful to touch only one line
at a time, but their fiberglass buckets isolated them from ground.
However, the fiberglass buckets do not have sufficient length and
insulation to allow them to work on the real high-voltage lines on the
big towers where the voltages are over 100,000 volts. In this case, if
they need to work on them live, they do it from helicopter. There was a
wonderful article about this in Smithsonian Magazine. Don't remember
the issue, but I think it was in the past five years.
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton College
Bluffton, OH 45817
(419)-358-3270
edmiston@bluffton.edu