Kurt, Just For The Record
>This has been a point of contention from John, W0UN, regarding how effective
>the torque bars can be. John is right (IMHO), that the torque bars can't and
>don't do anything until the tower rotates to some point where the guy is
able
>to exert a resisting force on it. I believe that the torque
>bars are effective, and empirical experience from others supports this.
Dana, the Rohn product manager at the Frankford, IN plant where
No. 45G is manufactured states the following (on 14 Aug 1998).
1) They came close to discontinuing the torque arm assemblies
because they don't do much, but kept them in the product line because
of customer requests.
2) They are an "unengineered" accessory.
3) And he stated "just between you and me, they are ineffective."
4) And "If you want to resist torque use the TA-45 assemblies and six guys."
>John mentioned that his experience at K0RF indicated something on the
>order of 45 deg of tower rotation at the top, for a non torque bar
installation,
>with a full sized 40 meter antenna.
Actually my statement to Kurt included the words "probably hyperbole"
indicating that 45 degrees was "severe exaggeration" (dictionary definition)
as a way of emphasizing just how much the tower FELT like it was rotating
under startup torque. I didn't (and still don't) recall for certain if torque
bars were used or not--but after thinking about it some more I THINK
that there were torque bars, at least at the top set of guy wires.
There was also a lot of sag in the guy wires, which were tensioned
appropriately, but which were quite heavy due to being 3/8 inch EHS
with lots of very large egg insulators.
Just wanted to set the record straight before my off-line comments were
used as the beginning of some major debate about torque arms.
I enjoy Kurt's contributions and he has provided many good insights
into the mechanics of towers (and his software is excellent).
73 John W0UN
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