[TowerTalk] Installing and tensioning guywires

[K7LXC at aol.com]

In a message dated 11/12/2006 6:43:07 A.M. Pacific Standard Time,  
towertalk-request at contesting.com writes:

>  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.


    The sequence is fine. The Loos gauge is pretty  accurate as is but no 
harm in checking it against your Dillon. Actually I  wouldn't even bother with 
the Dillon. The Loos is accurate enough and all you  have to do is hang it on 
the guywire without messing around with the comealong  et al. 
 
    You can pull a guywire by hand enough to put a  little tension on it. Do 
that with all 3 and then take a measurement. For  pre-tension, you just want 
all of them to be the same regardless of real  tension. Once the tower is 
plumb, from there just do equal turns of the  turnbuckles. It's easier if you've 
got someone on each guy and tell them "4  more turns" or whatever until you've 
got the desired tension. I usually don't  do the final plumb-and-tension until 
the tower is done. 

>   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. 
 
    See comments above. Install the first one with a  little tension and the 
other 2 the same way. Then go back and put some  measurable pre-tension on 
them. You won't have enough initial tension to worry  about. 
 
>  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. 
 
    That's where 3 comealongs and 3 grips comes in  real handy, but it's not 
absolutely necessary. You'll have enough scope in  your turnbuckle to handle 
it. Don't put the PreFormed grip on all the  way. Just wrap it 1/2 way to begin 
with. That way there'll be enough holding  power to hold the tower up but 
it'll come off easily if you have to move the  guywire. I don't do the grip final 
wrapping until the tower is finished. 
 
>  But to
do that, I'd have to install, undo and reinstall the  big grips several
times, which is not good.
 
    You can unwrap the grip twice, giving you 3 tries  to get it right. 
That's usually enough. 

>  Am I worrying  needlessly about this (i.e., there will be enough turnbuckle
thread) or is  there a trick to this?



         Yes, you're worrying  a little too much. It's got a little bit of a 
learning curve but it'll be close  enough after you've been thru an iteration 
or two and everything's fixable so  you'll eventually be successful. 
 
Cheers & GL, 
Steve       K7LXC
TOWER TECH -
Professional tower services for hams
Cell: 206-890-4188