In article , Tim
Streater scribeth thus
In article o.uk,
"Dave Liquorice" wrote:

On Thu, 22 Aug 2013 01:23:03 +0100, Arfa Daily wrote:

And, of course, add to this that pylons are spindly and what ? 60 feet
tall maybe ?

Small ones might be only 60' the 400 kV ones are just a *tad* bigger.
The insulator chains are a good 15' to 20' long. Each segment is a
large dinner plate in diameter and adds over a foot to the chain
length.

There is a set of insulators hanging in a corner of the Museum of
Science & Industry, Manchester, no information label though. It spans
two floors.

http://www.howhill.com/images/PICT0295.png

So 15' * 3 + spacings an up to earth wire at top 15' * 3, lower line
is about half way up the structure * 2 giving something of the order
of 200', or 60 m. About the height of the *hub* of a 2 MW windmill,
add another 40 m for the blades...

I sometimes observe that on switch gear and pylons insulators etc there
are odd pointy bits of wire etc - I even see that on rural lines where
there seem to be some sort of breakers. Assuming these are not merely
artistic whimsy on the part of the designer, what are they for?


I think your referring to "Arcing Horns" these are there to form a safe
point on most all HV installations for incidences like when lightning
hits the line they make a safe place for the current to discharge to
earth..

--
Tony Sayer