Path: utzoo!utgpu!watmath!iuvax!mailrus!ames!apple!malcolm
From: malcolm@Apple.COM (Malcolm Slaney)
Newsgroups: sci.electronics
Subject: Re: Re: Touching a "hot" connector
Message-ID: <33854@apple.Apple.COM>
Date: 9 Aug 89 05:26:22 GMT
References: <248@sopwith.UUCP> <17660006@hpfcdj.HP.COM> <3663@buengc.BU.EDU>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 25

In article <3663@buengc.BU.EDU> bph@buengc.bu.edu (Blair P. Houghton) writes:
>Major power companies repair high-tension (quarter-million-volt) lines
>in remote areas by sending cable dogs up in helicopters to work on the
>live wires barehanded.
>
>It ain't the volts that kill, it's the amps.

Just so nobody gets the wrong impression......working on live transmission
lines is an example of "doing what the birds do" and not an example of
high voltage and thus low amps is safe.

There is a long article on this practice in a recent issue of IEEE Spectrum.
It is not a universally accepted practice since one mistake is pretty fatal.

The basic principle is to work from a helicopter or an insulated cherry
picker.  As long as there is no electrical path to ground everything is
going to be fine.  These workers usually wear a conductive suit to keep
the electric fields constant everywhere and are physically strapped to
the cable so that they are always at the line voltage.

							Malcolm
P.S.  I decided to stick to computers after watching Commonwealth Edison
check to see if a 10-50 kV line was live in the rain by laying a wooden
stick across it and seeing if it sparked.  This was called fuzzing the
line.  Not my idea of a fun time.