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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