[Elecraft] OT: Ground rods and concrete

[Randy Lake]

This has been bugging me for a while and I am now in a mindframe to comment.
Lightening:
light·en·ing
ˈlītniNG/
*noun*

   1. a drop in the level of the uterus during the last weeks of pregnancy
   as the head of the fetus engages in the pelvis.

Come on !!

Randy
N1KWF


On Tue, Apr 18, 2017 at 7:39 PM, Ken G Kopp <kengkopp at gmail.com> wrote:

> I was the first to use the term "exploding tower base" in this discussion.
> The term "exploding" was probably not correct.  As several others have
> phrased it, an instant expansion of steam is more correct.  Concrete is
> never totally "dry" in the context of this conversation.
>
> I witnessed lightening blowing apart the two tower bases I spoke of in
> person, directly, and in real-time. It happened in the mid-sixties at the
> St. Petersburg, FL Coast Guard base.  As someone else has mentioned;
> the Tampa Bay region has the highest incidence of lightening in the
> Western Hemisphere.  To the one of you who accused my of lying ...
> I was there ... you weren't.
>
> At the time I was an ET aboard the USC&GS (Now NOAA) Oceanographic
> Survey ship Hydrographer/WTEI and we were in the area deliberately
> attracting lightening with balloon-hoisted cables.  I -do- know something
> about the infinite uncertainty of lightning.
>
> I'm a retired electric power company two-way radio tech and have probably
> dealt with more types of towers than most of you.  Large electric
> transmission
> line towers are almost always set on four concrete piers, and are grounded
> with (usually) copper straps cad-welded to each tower leg and connected to
> ground rods a bit away from the cement.  Each of us can search long enough
> to find "facts" that support our various positons, especially on today's
> Internet.
>
> Here in the mountains of the West ... as well other regions ... finding and
> maintaining a "good" ground at a radio site atop a mountain can be a
> "challenge".  It's almost never done with ground rods.  My power company
> employer has several hundred mountain-top microwave and/or radio sites.
> Been there, done that, as they say.
>
> One responder spoke of fitting a copper pipe with a garden hose fitting and
> "flushing" it into the ground.  That works very well, and is how some of my
> 14 grounds are installed.  It helps if the downward end is partly
> flattened, BTW.
>
> A much bigger problem overall than lightening is water collecting in tower
> legs,
> especially in climates where it can rust (undetected) from the inside and /
> or
> freeze and split one or more legs.  There's an accepted way to avoid this.
>
> 73!
>
> Ken Kopp - K0PP
>
>
> On Apr 18, 2017 at 4:30 PM, <w5sum at comcast.net> wrote:
>
> > some 40 years ago, maybe longer I put up a 50' rohn 25G tower. Dug the
> > hole
>
>     and set the tower base in it alone with a 12' 3/4" ground rod and
> poured the
>     cement, left about 6" of ground rod protruding. I bonded to that rod
> and grounded
>     the tower. 3 years later I had a huge lightning strike on my tower and
> yes.. it cracked
>     that base.
>
>     never again
>
>     Ronnie W5SUM
>
> > ______________________________________________________________
> >
> >
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-- 
Randy Lake N1KWF
73 Gunn Rd.
Keene,NH