-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Donald Chester
Sent: Monday, April 04, 2011 12:20 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Temporary Guys
>Another must to avoid is tensioning the guys to maximum during hot weather,
>since they contract during extreme cold, resulting in over-tension during
>sub-freezing periods in winter.
I've never erected a guyed tower, but I was curious about the engineering
behind that. The thermal coefficient of expansion of steel is 0.00000645
in/in/def F. Calculating for 115' of guy wires, I come up with a change of
0.8901" for a 100 degree F swing in temperature.
That might be a lot, but the tower (90' - I thought I read here recently that a
90' tower needs a 115' guy at the top) also shinks 0.6966" for the same swing
in temperature. Without doing the trigonometry, that's something less than a
quarter inch in total added "tension".
Like I said, I have no personal experience, but that doesn't sound like a lot
to me. Am I wrong?
Al
AB2ZY
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