Hi. Finally started stacking my 110' Rohn 55 tower. We have 40' up with two
sets of temporary guys (AB-577 stainless guys, actually, which work nicely
for temps.) The permanent guys are attached to the guy bracket at 33' and
are ready to be connected to the anchors and tensioned. The guys are
Phillystran, but with EHS leaders at the bottom. I'm using Big Grips.
I'm curious about the detailed sequence for tensioning the guys. I have one
Klein grip and one come-along. I also have a Dillon Dynamometer and a Loos
gauge. I think I understand the general sequence for tensioning one guy:
1. Attach one end of come-along to guy anchor
2. Attach other end of come-along to Klein grip
3. Attach Klein grip to EHS ahead of where the big grip is likely to end
4. Unscrew turnbuckle most of the way, leaving about 1-2" of thread (I'm
using 12" turnbuckles)
5. Use come-along to tension the guy near the final pre-tension figure.
6. Install shackle, thimble and big grip on free end of guy.
7. Release come-along.
8. Use turnbuckle to reach final pre-tension.
As for determining tension, my plan is to put the Dynamometer in line with
the come-along and use it in step 5 and to calibrate the Loos gauge. That
way, I can use the Loos gauge to determine tension after I've removed the
come-along and Dynamometer.
What I'm not sure about is how to approach doing all three guys. If I
tension the first guy near to the final pre-tension figure, as in step 5,
then it seems to me that the tower will be pulled off plumb, and I might not
be able to pull it back by tensioning the other guys. But if I don't put
enough tension on the first guy, then I might run out of thread on its
turnbuckle. It would seem like this is an iterative procedure, and that it
might require unclamping and retensioning each cable several times. But to
do that, I'd have to install, undo and reinstall the big grips several
times, which is not good.
Am I worrying needlessly about this (i.e., there will be enough turnbuckle
thread) or is there a trick to this?
73, Dick WC1M
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