Angle or even horizontal will work.
You can drill out the hard layer and backfill,
although the rod-to-earth contact will not be as
"tight."
Because of the material, you may want to consider
conductivity-enhancements such as GEM or coke breeze.
73,
Bob AA0CY
ex Senior Applications Engineer, PolyPhaser Corp.
----------
From: Bill Aycock[SMTP:baycock@hiwaay.net]
Sent: Saturday, April 10, 1999 7:05 PM
To: Tower Talk
Subject: Re: [TowerTalk] Ground Rods
In all the recent discussion, I have not seen anything connected to my
particular problem.-- I have a rock (sandstone, I think) layer about 6 ft
down at the tower base site. An 8' rod driven into this stops -dead- with
from 1 to 2 ft of rod above ground.
Most specs and codes that I have seen ask for the top of the rod to be
sub-surface, and to have clamp contact of the wire to the rod. This does
make for difficulty in inspection, but thats what they say.
I plan to drive my tower-base safety rods at an angle, to use all the rod
without hitting the rock. Doing this will give me the same contact area
(length) as if I had driven it in with no interference.
I found this layer when I was driving the house service entrance ground
several years ago. The local utility forman said to just leave the
remainder above the surface (it was next to their pole) and tie in with a
clamp. They apparently saw similar things with some frequency.
I was reminded of this when I tried to drive the first rod for the tower.
now- a foot or so of rod sticking up next to a power pole is one thing,
but, the same thing ten feet out from the tower base, in open yard, is
another. Those things are HARD to cut, too.
I know that most ham tower people prefer fusion weldment to clamps, and I
may go that way. However, the question I invite comment on concerns the
plan to drive at an angle, rather than going as far as I can, and cut the
excess. I plan to pull the one that is in now, and redrive it.
A tractor with a boom and a chain does wonders as a "come-along" to stuborn
fence posts and ground rods.
BTW- I have seen some comments about electric utility people- let me say-
the ones we have are among to best. Both very professional and dedicated.
I live in a rural setting, and feel very comfortable about "outages"- they
are rare and short.
Bill- W4BSG
-
Bill Aycock --- Persimmon Hill
Woodville, Alabama, US 35776
(in the N.E. corner of the State)
W4BSG -- Grid EM64vr
baycock@HiWAAY.net
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|