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Re: [TowerTalk] Tower Base rotated 5 to 10 degrees off correct bearings

To: Richard Smith <n6kt1@sbcglobal.net>, "towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] Tower Base rotated 5 to 10 degrees off correct bearings
From: Grant Saviers <grants2@pacbell.net>
Date: Wed, 9 Aug 2017 06:35:12 -0700
List-post: <mailto:towertalk@contesting.com>
I would avoid any fix that puts a torque on the tower. TIA-222-F sec 6.1.1.2 re tower twist - "No more than 0.5 deg in a 10' elevation change and no more than 5 deg entire tower". So your guy locations may violate that rule. IIRC, +/- one degree, maybe two is the standard for guy anchor position accuracy. IMO (not a PE) a stiff adapter frame mounted at each level with guy attachments at the anchor 120 deg positions would work as well as the guys directly to the legs. After all, a rotating tower has guys pulling at every possible angle with respect to the legs rather than directly bisecting the leg angles. By "stiff" I mean something fabricated like 3x3x3/8 angle and hot dip galvanized since it is PJ4. This is where I'd get a PE design/analysis for a tower this tall with a 24" face. I'm not familiar with how the guy attachments work on AB-105, but attaching at a cross bar is the standard for R65. The fab, any welding, and HDG could happen in the USA.

Grant KZ1W

On 8/8/2017 22:10 PM, Richard Smith wrote:
Asking for some assistance with a tower issue...
I'm involved with some folks in building a station in PJ4. One of the first 
tower bases was accidently set in concrete in a position that it is rotated 5 
to 10 degrees from its correct position in relation to the guy anchors. I'm 
hoping that there might be a good suggestion or two as to what might be a good 
fix or work-around.
The tower is AB-105, and the base is a section of AB-105 set in concrete. The 
plan is to have the tower built up to 140 feet, with guys at 40, 80, and 120 
feet.
Some alternatives:
If we "use as is", will the torque of the guy wires cause problems for the 
tower?
Should we consider some kind of adaptor plate for the guy brackets to correct 
the situation?
Are we stuck digging and pouring a new base, or new guy anchors, with the 
correct positioning?
Any ideas will be much appreciated.
Thanks, 73,
Rich, N6KT



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