I would not consider any kind of fibre rope for temporary guys for several
reasons already cited here. One more danger is the possibility of improper
tying. That happened to me years ago putting up a 25G single handedly. I used
the standard Rohn gin pole, and did everything by the book, except that without
a helper, I would stand on the ground, tie the sisal rope to the tower
section, hoist it up to position from the ground, tie off the rope to a tower
rung near the ground, then climb the tower with the section dangling in the
pulley and fasten it in place. This went without mishap until I was at the
100' level. I had just tied and hoisted a section and decided to take a break.
I sat down in the shade, and looked up at my handiwork, and to my horror,
watched as the tower section tumbled down. Evidently the knot where I tied the
rope at the bottom end came loose. My first thought was that the wayward
section would surely hit a guy and the shock wave or broken guy wir
e would cause catastrophic failure of the whole tower. Fortunately, it struck
only one of the bottom set of guys, and the only damage was a chipped strain
insulator. A rung of the dropped section was bent about 30 degrees, so I
discarded it and purchased a new one. I was glad this didn't happen while I
was up on the tower. I suspect that the only thing that prevented destruction
of the tower was the fact that the descent was slowed way down as the falling
section was pulling the heavy rope from the ground all the way up through the
gin pole pulley and back down again. From then on, I made absolute damn sure
the rope was securely tied and re-checked multiple times at each end before
hoisting a section and then climbing the tower.
I have never felt secure on a tower beyond one section above a permanent guy
point, so I attach a set of temporary guys to each section as I go up,
installing the permanent guys as soon as I reach guying level. Of course, I
use guying brackets and thimbles. I have used #10 copperweld antenna wire for
temporaries, along with 3 ea. cable clamps at each termination, and always felt
plenty secure. My tower is a pier pin type, so once I reach the first set of
permanent guys at 30', the temps serve to provide peace of mind more than
physical safety. I could read the Rohn installation guide and tower specs many
times over, stand on the ground and look at the tower and easily convince
myself that it is perfectly safe to climb up 3 sections above a permanent guy
point without temporary guys, but once on the tower the first time I feel the
tower sway when shifting my weight, I am totally unconvinced. The temps
provide the solid feel and stability that allow me to climb and work wit
h near-perfect ease. I was never afraid of heights as long as I am sure that
the structure I am climbing on is secure. To reduce the likelihood of an
accident by human error, a secure feeling without undue anxiety whilst working
at 120' off the ground is just as essential as having the proper climbing
equipment and following all the recommended safety procedures.
When replacing or repairing a set of guys, I would never disconnect more than
one permanent cable at a time, with the temp already in place before attempting
to disconnect the permanent. A calm day is essential as well. The temporary
guy should never be called upon to carry more than a small fraction of the
tension expected of a permanent guy wire under all conditions.
Another (non-climbing) near mishap occurred while I was sitting on the ground
attaching strain insulators to EHS guy wire. I followed the Rohn suggestion to
use three cable clamps and then "serve" the strands by wrapping each strand of
the dead end of the guy round the main guy cable, until running out of strands.
It was a cold, blustery day, and apparently EHS becomes brittle at low
temperatures. After I had attached all 3 clamps, I was "serving" the strands
by manually wrapping them wearing leather gloves, then pulling the final wrap
tight with vice grips. While wrapping, one of the strands snapped in two, and a
piece about 2" long flew off and hit me right in the eye. Looking in a mirror,
I could see a small dimple on the cornea where the piece hit, but other than
discomfort, no permanent damage was done. But when I examined the end of the
strand where the small piece snapped off, I saw that it had separated at a very
oblique angle, leaving the broken end of the guy
as sharp as a needle. I was EXTREMELY fortunate that the separated piece hit
me in the eye broadside and not at the sharp end! Needless to say, following
that incident, I always wear safety glasses when doing any kind of work with
EHS or similar wire. Actually, I would prefer to use the old HS guy cable
instead of EHS if they still made it, since it is more pliable and my tower
doesn't need the EHS breaking strength. Years later I had to replace some
strain insulators, and used Guy Grip pre-forms instead of clamps and serving.
They go much more quickly and easily, well worth the additional expense.
Something I don't quite do by the book is adjust guy tension all the way to 10%
of breaking strength. With 3/16" EHS (breaking strength 5000 lbs IIRC) that
would mean 500 lbs tension on each guy wire (maybe less if I incorrectly recall
the breaking strength), which to me would seem to unnecessarily load down the
tower. I was told by someone that the reason for all that tension is to reduce
swaying of the guy wire in the wind, which can fray the cable as it swivels to
and fro over the point of attachment, but using thimbles and guy brackets, the
sleeve that fits over the bolt is designed to rotate, so I don't see any
increased likelihood of failure. I tighten the guys until I feel comfortable
with the amount of sag, play and feel of the wire, probably somewhere around a
couple of hundred pounds of measured tension or maybe a little more. But I
make sure the tension is very close to the same for each guy, and that the
tower is plumb at each guy point. Another must to avoi
d is tensioning the guys to maximum during hot weather, since they contract
during extreme cold, resulting in over-tension during sub-freezing periods in
winter.
Don k4kyv
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