Guywire Overkill?
N6IJ has large amounts of 5/16" guy wire, and associated
hardware, a benefit of the base closure at Ft. Ord. Reading the
accepted practice of tensioning at 10% of ultimate strength, I
wonder if there is any such thing as using too heavy of guy strand
for a ham installation. This strand was used and will be used mostly
on 70 ft. wooden poles, but may be used on a 140 Ft. insulated
base broadcast tower, and maybe other metal towers such as Rohn
25. If I tensioned it at 10% for Rohn 25, I would be generating
considerable downforce on the 25...possibly too much. Book says
5.16 EHS strand breaks at 11,200 lbs. Each of three guys tensioned
at 1100 lbs, and 45 degrees, looks like over 2000 lbs vertical force
(just a guess, no calculator....) Can I tension at much less than 10%
without negative effects? (Any comments?)
BTW, following others advice, I got the BOOK by Preformed
Line Products Co. (216) 461-5200, and recommend it highly to all who work
around towers. Be sure to look at the photo of many 1500 lb concrete
blocks being scattered like croutons, when the 1000' strand they
constrain, snaps, under more than 100,000 lb tension.
There is obviously MUCH MORE to this guying thing than is
obvious to even the very sharp, but inexperienced eye. This whole
topic looks more and more to be one where a little information, no
experience, extremely sharp, motivated minds, and a sense of
adventure can add up to a very dangerous situation. I recon there
are many ham antennas that are still up only through the grace of
God, and are disasters waiting to happen.
Why not have seminars or workshops put on by experts on the ins and
outs
of rigging......I vote for Monterey as the first location to hold
the.... lets call it.... the Guy guys convention.....Anyone need some 5/16"
EHS?
73, DX, de Pat, AA6EG/N6IJ....Marina CA..... the contest statin from the
government.
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