Typically twisting within any tower is deadly. Once twisted to far, the tower
will buckle and collapse.
I inspect my towers for weld cracks and other anomalies annually.
A Torque Arm assembly is located 2/3rd up the main tower and reduces tower
twist from an side mounted antenna array.
A Star Guy assembly is located at tower apex, twist movement - perhaps 1 degree.
The second tower only has Torque Arm assembly.
Thanks,
James
ki5dq
--------------------------------------------
On Sun, 1/8/17, john@kk9a.com <john@kk9a.com> wrote:
Subject: Re: [TowerTalk] torque arms or not?
To: towertalk@contesting.com
Date: Sunday, January 8, 2017, 9:10 PM
Actually torque arms do almost nothing to stop twisting, you really need to go
with a 6-way guy. For that kind of wind, you might need the solid leg Rohn 45
and lots of guys.
GL,
John KK9A
Subject: [TowerTalk] torque arms or not?
From: DALE LONG <dale.long@prodigy.net>
Reply-to: DALE LONG <dale.long@prodigy.net>
Date: Sat, 7 Jan 2017 20:56:40 +0000 (UTC)
This brings up a related question. We lost a lot of towers in southern Haiti
during Hurricane Matthew. Most of them were newly built 100-120 ft Rohn 25
towers with adequate guying and torque brackets but not torque arms.
Here is a question for the tower professional. If you are not using a
rotator,
but only some VHF antennas at the top, how important is it to add the torque
arms. We use a baseplate with pier pin so we are allowing for some movement
at the base.
Our tower in Dame Marie was hit by 145 mph blunt force winds and I dont know
if anything would have survived. But several towers folded over, with the
guy
anchors and guy wires intact. We are thinking that we need to move up from
Rohn 25 just to survive the hurricanes, although the antenna wind load is
minimal.
To include torque arms or not, that is the question. (for tower without ham
rotator). Will the oscillations be reduced by the torque arms?
Dale - N3BNA
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