SB: Re: FWD Re: Lightning strikes

["Richard" <rharris1@ec.rr.com>]

Robert (and Mark),
Thanks for en-lighting us. <G> It took me a while to digest your post and I
find it facinating.

I've been taught that if lighting were to strike a sealed metal container,
the charge would travel across the exterior and not harm the interior. I
suppose that is airplanes are not usually affected by the occasional hit.
Leon Byerley's conclusion that the chicken wire will act as a virtual
container to exclude the charge is encouraging.
( http://www.physlink.com/ae176.cfm  See also the "Air Terminals" at the
lightning protection system design URL below )

Richard H
-------------

PS:
In doing some searching on the web, I found this from George Rogato:
http://lists.contesting.com/_towertalk/199909/0146.html

 Being an Electrician , I can explain to you exactly what a UFFER ground
is .
Uffer . named after Dr, Uffer , who did extensive testing of different
grounding systems in Arizona.
 (Arizona being one particular place where they have : a- lots of
lightning and b- poor soil conductivity  conditions)
Uffer .. Slang for  ' Concrete Embedded Grounding Electrode '
Typically a uffer is a #4 copper conductor placed approx. 2" above  the
bottom of a concrete footing at a minimum of 20' long
Naturally the purpose of the 'Grounding Electrode " is for lightning
protection.
According to the National Electric Code ....metal buildings or structures
are to be  bonded to a grounding electrode conductor . Even if they are
solidly embedded in concrete . Bonded means you connect the metal frame to
the grounding electrode (uffer) conductor .


---------------------


For those interested in knowing more:

https://128.174.5.51/denix/Public/ES-Programs/Explosives/Safety/CH07.html
Lightning Protection System Design
( I did receive a certiicate warning, but don't think it is a problem and no
cookies were exchanged)

 http://www.pbf.org/Archive/ReducResist.htm Reducing Resistivity In An
Electrical Grounding System

http://www.lightningsafety.com/nlsi_lhm/steps.html Six Steps to Lightning
Protection (NATIONAL LIGHTNING SAFETY INSTITUTE)

http://soilslab.cfr.washington.edu/esc110/2000Spring/projects/Group39/preven
t.html




-------------------------------------------------------------------------
To unsubscribe from the list, send a message to:
   <strawbale-unsubscribe@crest.org>

or for the digest to:
   <strawbale-digest-unsubscribe@crest.org>

Please send any list administration questions to
strawbale-owner@crest.org