Gerald:
Actually I don't think any of it is attributed to the fact it is 4-way
guyed. A design condition would be with the wind load in line with one of
the guys. In this case one guy is taking all the load and the other three
are not. It is the same as my other response.
The use of 4way guying allows for easier tilt over for the tower in lieu of
3-way. Always have the side guys helping to control the side to side
direction of the tilt over.
Again it shows that you can place the guy anchor points at some distance
other than 80% of the height. You just need to calculate all the forces and
design for what they are.
Hank Lonberg, P.E. / KR7X
Beaverton, OR USA
Kr7x@arrl.net <mailto:Kr7x@arrl.net>
Hank.Lonberg@harrisgrp.com <mailto:Hank.Lonberg@harrisgrp.com>
Team Pantelleria - IH9P - African Italy - CQWW DX SSB
http://www.qsl.net/ih9p/
<http://www.fortunecity.com/skyscraper/eudora/126/ih9p.html>
-----Original Message-----
From: TexasRF@aol.com [SMTP:TexasRF@aol.com]
Sent: Thursday, November 18, 1999 8:25 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Rohn 25 guy radius oddness.. 80% vs
50%?
Another perspective on this question:
If you examine the guying specs for a Rohn 48ft Foldover tower model
FK2548
ypu will find a recommended guy distance of only 18 feet, or 37.5
percent of
the tower height! This is with a wind load of 13.3 square feet as
well.
The guy plan is for a four way guy system. Perhaps someone can shed
some
light on how much of this shortened guy plan can be attributed to a
four way
versus three way guy plan.
It makes sense to me that a standard (non foldover) 25G tower could
be used
with the four way shortened guy system just as safely as a foldover
tower.
Anyone else have any thoughts about this?
73 de Gerald Williamson, K5GW
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