Actually, there is a 15% reduction in the worst case guy load
using 4 way guying vs. 3 way. The worst case load with 3 way
guying occurs when the wind is blowing parallel to one of the
tower faces, 30 degrees away from the upwind guy wire. This
slight difference does NOT account for the close guying plan
for the tilt-over towers.
The tiltover guying arrangement tells us that there is a
CONSIDERABLE reduction in tower loading with a 70 ft
tower versus the full 200 ft rating of Rohn 25 where 80%
guying is mandatory for even modest antenna loads.
de Tom N4KG
On Thu, 18 Nov 1999 11:25:01 EST TexasRF@aol.com writes:
>
> 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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