There are a few crank-up towers that were designed to be optionally guyed. The
one I'm familiar with is the old EZ-Way crank-ups that have beefy brake plates
which flip in to hold the section above and thus take the loads off of the lift
cables. A quick web search for old EZ-Way Tower brochures will show some info.
I have an EZ-Way RBZ-75 which is guyed at the top of the first and the second
sections. Once I have the sections locked, I take most, but not all, of the
tension off the winch cable. The lower guys are preloaded (Loos gauge) at the
normal 400 lbs for 3/16 EHS but I keep the set for the second section a little
backed off, to about 250 lbs.
That said, the complex load paths through the brake plates onto the rungs at
the next lower section would certainly make a FEM analysis of this setup quite
difficult.
After many years, I have not had any problems with this setup carrying an
Optibeam OB9-5 and a dual band VHF/UHF vertical. But I'm also surrounded by
tall trees that significantly diminish the wind loads. My biggest risk is one
of those big trees falling on a guy line and pulling everything over.
If the crank-up does not have design features to lock the sections and the
manufacturer's instructions do not specifically say it can be guyed, then
don't guy it. The loads into the lift cable will be too much for it. Final
note ... even with these section locking features, I do not consider the tower
safe to climb. When it's maintenance time, the top and middle sections get
lowered and a man-lift used.
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