Back when I was a co-op with Southern Bell in the Atlanta area, we were
presented with this problem in order to ground telephone booths. It seems
Stone Mountain extends a lot further than what you see. The solution was to
deploy a construction crew with a 48" x 1 1/4" hammer drill bit, to drill
two holes to a depth of 48" and attempt to drive the rod beyond that. If
that worked, the hole was grouted shut around the rod. If it didn't work,
the rod was to be cut to 48" and each end grouted into the two holes, both
connected to the booth with #6 solid copper.
One Monday morning, I came to work and heard that someone had been killed
in a phone booth. Springtime lightning storms were widespread that weekend,
so I just knew this grounding had killed someone. My boss and I went out to
the site, but it turned out that there was a phone booth thief that had
figured out exactly how to shoot the door off a coin telephone to free the
cash. In this case, he didn't anticipate the richochet.
73,
Mickey N4MB
On Sun, Jan 18, 2015 at 10:27 PM, <john@kk9a.com> wrote:
> I have a similar problem, a 70# jack hammer will not drive them all the way
> in. I just used more of them to compensate.
>
>
> John KK9A - W4AAA
>
>
> To: maflynn@theflynn.org
> Subject: Re: [TowerTalk] w7ekb & ground rods
> From: Ken <wa8jxm@gmail.com>
> Date: Sun, 18 Jan 2015 20:00:45 -0500
>
> If I may ask, what's the "appropriate tool" when you have a rock layer 40"
> down? i tried a hammer drill, waste of time. I rented an SDS-MAX hammer
> and I
> got one in all the way, four others only made it most of the way. So what
> is
> the recommendation?
>
> Ken WA8JXM
>
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