In a message dated 98-06-18 17:23:04 EDT, k0wa@southwind.net writes:
>>A previous post about guy wires loosening up due to temperature changes.
> >Something has changed. How many turns did you take on the turnbuckles? All
> of them or just one?
>
> Actually, I tightened two up. The one in the front yard has a safty cable
> going though it with saddle clamps. THe turn buckles were hard to turn
> also, so I don't think they turned on their own. Privacy fence too...I
> don't think vandals are the case either. Checked the guy point...no
> heaving. I also used cable grips and I have marked them to see if the are
> slipping. Everything seems to check OK.
Okay. Let's assume for a minute that it was natural temperature induced
expansion/contraction. Here is the temperature change information relating to
ambient temp and guy wire tension at 10% of breaking strength (these are the
values for desired tension at different temperatures):
3/16 inch EHS
120 degrees F 300# tension
90 350#
60 400#
30 450#
0 500#
1/4 inch EHS
120 degrees F 500# tension
90 585#
60 665#
30 750#
0 830#
You can see that these are basically linear relationships. These figures
include the effect of tower height change. This information is taken from the
Rohn Tower Inspection Manual.
So you can see that you need to compensate for temperature. If the
initial tension was done in the winter, then they will 'loosen' up due to
higher temperature expansion. But if you use the above factors, the tension
should be within spec for the whole year no matter when the reading was taken.
>
> I've had season tempurature changes before like this.... this is not the
> first time I've had to adjust between hot and cold. Need to get one of
> those LOOS tension gauges
That would be my advice. Get a Loos or similar device to make sure you
KNOW that the guys are tensioned properly and then verify their value during
your annual inspection. Then you won't have to worry about
tightening/loosening them. (You really didn't know what the tension was
anyway, did you?)
Commercial plug: the Loos tensioners are available at
www.championradio.com.
Cheers, Steve K7LXC
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