[TowerTalk] guy placement questions

[Jim Lux]

At 11:04 AM 4/10/2006, Dick Green WC1M wrote:
>
>Question 3 - Guy radius: The SteppIRs need at least 25' of turning radius
>(24' plus one foot for the TIC ring.) The middle SteppIR will probably not
>clear the top guy if the guy radius is at the Rohn nominal 80'. If I put the
>guys 85' out (slightly over the spec of 80% plus or minus 5%), then I'll get
>about 3 feet of clearance. If I put the guys 90' out, then I'll get about 5
>feet of clearance. How do I compute the expected sag in the guy wires?
>(Note: The plan is to use phillystran guys.) Does 3 feet leave enough
>margin? Does 5 feet leave enough margin?

On sag in catenaries:
http://home.earthlink.net/~w6rmk/math/catenary.htm