The 80% anchor distance is just a general guideline, many towers are
safely built with much closer guy anchors. Rohn engineering should be
able to help you with this. It may be as simple as just using larger
guy cables, I use 5/16 equivalent on my Rohn 65 tower.
GL
John KK9A
Matthew KA6? wrote:
TL; DR: fire got my tower, can’t replace at same height with stock guy
anchor distance.
I had a Rohn 55 tower that was built in 1971 as 150’ high with 4 levels of
guys and anchors 120’ from the base. Some ten years later they put two more
sections on, making it 170’, and added a 5th guy level (and borrowed the
4th level’s spot on the guy anchor plate for it)
A couple weeks ago the anchors got melted in the CZU Lightning complex
fires (the camera on top caught the fire:
http://www.alertwildfire.org/southeastbay/index.html?camera=Axis-BonnyDoon&v=81e002f
before the camera and microwave cables melted)
I want to replace the tower with 170’ (or 180’) of Rohn 65... but due to
property lines, I can’t get more than a couple more feet out past 120’ from
the base(the default for a 150’) Has anyone on the list gone through the
engineering for guys that are closer to the base than the stock design
calls for?
Due to trees, the first 90-100’ of the tower is virtually unusable, so
every foot counts.
Matthew Kaufman
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