[TowerTalk] Conductive Concrete and Grounding

[Tom Rauch]

> I have seen a couple of tower bases cracked / split from
lightning going
> into the J bolts. But these were on installations with no
ground rods
> attached!


I saw a base pier on a BC tower (self supporting, so it had
three or four piers) split from what looked like a big arc.
They only had a gap and ground on one leg.

It isn't unheard of for lightning to shatter big insulators
in guylines.

I agree it may be rare, but I don't see why people think it
*can't* happen. Geeze, I had 7/8th heliax and other stuff
melt. I'd be darned if I would want something like that to
go through the poor conductivity of concrete.

By the way, good and poor are subjective terms. Try to run a
car starter off concrete jumper cables, or even salt water.
Salt water actually can make a darned good 50 ohm dummy
load. I bet chemically treated concrete wouldn't.

Anyone know what the resistivity per unit volume concrete
is?

73 Tom