This topic is particularly timely for me. I'm working on tower project
#2, and I'll be ready to pour the base and anchors any day now.
Several folks have already mentioned the anchor rod slope tolerance of +/-
1.0 degree, specified by Rohn. I agree that seems arbitrarily tight.
Rohn also specifies +/- 1.0 degree each on "anchor head out of plumb" and
"anchor rod alignment with guy radius." O.K.
But the one that I really don't understand, even after reading it several
times and scratching my head, is this:
"Anchor alignment (perpendicular to guy radius) - 0.1 degrees"
What does that mean?! Note that this is an entirely different spec from
"anchor rod alignment with guy radius."
Does that mean the piece of angle at the bottom of the anchor rod (welded
on by Rohn) must be perpendicular to the guy radius within 0.1 degrees?
Or the entire concrete block (and thus the holes that I just dug) must be
within 0.1 degrees of perpendicular to the guy radius? Either one sounds
absurd to me. I can't imagine there's a backhoe operator on the planet
that can consistently dig perfectly rectangular holes to within 0.1
degrees, much less aligned perpendicularly to the guy radius with that
accuracy. It might be possible with a small shovel, a LOT of patience,
and some professional survey equipment.
But before I shrug off the spec, I'd like to at least be sure I understand
what they are trying to say. Can anyone shed some light?
73,
Tim Totten, n4gn@n4gn.com
http://www.n4gn.com
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