Grounding tower legs

Thu, 7 Nov 96 11:09:31 PST

	N0YVY in responding to my use of battery cable wondered how long
it would take the cable to melt from a direct hit. I don't have any idea
of the voltage or current generated by a hit, but would imagine the voltage 
to be several hundred thousand, and the current enormous. 

We should also keep in mind that lightning originates from the ground
UP, not the way we see it. I would assume therefore that as long as the
tower is held at ground ( whatever that magic number is ), it would be
impossible for it to be hit. However, that brings up an interesting point.
In the beginning, the legs are all nice and clean, and probably the entire
tower is around 0 ohms resistance. But, as time goes by, corrosion does
form ( it once took me 4 hours to jack 2 sections apart ( on the ground )
and although I live several hundred miles from the ocean, there was
contamination on the joints. We all get pollen, and various forms of
polutants from the air. FINALLY, the question. Is the incidence of
tower strikes directly related to the age of the tower. My oldest one is
19 years, and it took its first hit at about age 10. And has had 2 or 3
since. #2 tower is 41' higher, 2 years old, 100' from #1, and has never
taken a hit. #3 is only a few months old. 

Your experience would be very helpful. If it is as I am beginning to 
suspect, we're going to have to add maintenance in the form of cleaning
the outside of each joint, and bonding it from bolt to bolt. I think I
may cut up an old section into 6" pieces, cut them in half, clean them
and then use them as the bond.

Another question. Would it be necessary to bond every joint, or would 
going up in order on one side be OK?

73,

Ed
-------------------------------------
Name: ed sleight
E-mail: k4sb@avana.net
Date: 11/7/96
Time: 11:09:31 AM

This message was sent by Chameleon 
-------------------------------------

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 K7LXC@contesting.com
Sponsored by Akorn Access, Inc & KM9P