[BC] Lightning

[Bruce Doerle]

Alan,

You could possibly be right on the glassification because there are too many variables with lightning; there is no exact science to determining what lightning will do and where it will go.  So I won't hold anything to a firm rule on the glassification around a ground rod. But the reports I have on glassification is that it occurs in the soil near the top of the rod and since most lightning strike occur during rain storms and since we have fairly sandy soil, I would expect that most lightning rods would be wet near the surface.  Who knows for sure.

However, I don't have to prove that lightning will bypass 'prevention' systems; there already is enough examples that you can go read about including some mentioned in the Polyphasor bulletin I used in an earlier post.

Look forward to getting together, probably be at the end of June sometime,

Bruce

>>> radiotech at bellsouth.net 05/25/05 5:14 PM >>>
I suspect the area of glassification depends greatly on the moisture 
content of the soil. I.E. a strike when/where the ground is wet probably 
would not cause much of a problem. If you were in the middle of a 
drought and the ground was dry, it could possibly occur down the entire 
rod.

Bruce Doerle wrote:
> This is an excellent point of which one we should be aware.  The sand
> around the lightning rods can become glassified under extreme
> strikes.  But any strike strong enough to this will also bypass the
> 'prevention' devices anyway.  

Maybe maybe not, I still stick to my position that you can't prove this 
one way or the other.

> So there is not much you can do to
> really prevent glassification.  It is more important to develop you
> ground system to dissipate the energy across multiple lightning rods
> to reduce the currents and heat.  You can determine the affects of
> the glassification by measuring the earth resistance to ground system
> periodically or buy a shovel.  From what I understand most of the
> glassification really only takes place near the surface where the
> currents are the strongest.

> I need to come back up to your area soon to see the bird hatchlings
> out at the Alligator Farm.  Maybe we can get together when I get
> there.

Just let me know, I'd enjoy saying hello again :)

-- 
Alan Alsobrook CSRE AMD CBNT
St. Augustine Fl. 32086 904-829-8885
aalso at Bellsouth.net


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