[TowerTalk] Fwd: Relatively large tower base install questions.
Patrick Greenlee
patrick_g at windstream.net
Tue Mar 5 10:45:24 EST 2013
My apology for using the term "pipe" loosely. Of course it is structural
tubing with circular flanges welded to each end of each of the 12 ends.
Multiple through bolts attach the 20 ft sections together at the flanges to
make 40 ft. I'm sure if the tower had been used to support an antenna it
would still be in fine shape but the gyroscopic forces eventually work
hardened the bolts and caused the failure. I will be replacing the bolts.
I intend to cut off the tops of the tubing embedded in the piers to be able
to reuse the flanges. I will weld on telescoping tubing to replace that left
behind in the piers.
As regards "The Base", the installation didn't have one large "lump" of
concrete for a base, just the 3 piers 18 inches in diameter and 7 ft into
the ground with tubing embedded to provide flanges to mount the tower. I
think the width of the tower's "stance" at over 14 feet contributed greatly
to its stability and lack of a requirement for a massive lump of concrete.
Given its aspect ratio with the top 60 ft removed (over 14 ft wide at the
bottom and only 40 ft high) erecting it on the ground and tilting it up
should be relatively straight forward considering I have a tractor with a
front end loader to let hydraulics assist muscle, a 12,000 pound pull winch
on the front of a one ton dually diesel Dodge truck, and two of the tower
base connections are very stout tilt over hinges.
This may not be the first time something like this has been done but it is a
first for me and I have never heard of nor seen anything like it. I haven't
worked out the details of how to mount a crank-up free standing tower inside
this 40 foot tower but it will not include concrete. Even with a crank-up
tower fully extended from inside it with a couple antennas on that the load
on the tower base will still be significantly less than it had when the
original full 100 ft were intact, and more so if you consider the load and
drag of the wind generator which is considerable.
I suppose I could take a few more progress snaps and post them as there
might be some interest in seeing how this project goes. Next Monday is the
date of a brush clearing expedition to clear brush and trees that have grown
up and are intertwined with the legs and braces of the first 20 ft section.
The picture labeled Big Tower is a shot of one of the tilt over hinges.
The misspelled Flangte and pier is a picture of one of the piers and
flanges.
Tower is a shot of the whole thing as it sits in the brush.
The rust is light, superficial, and not flaky. It will clean up easily. I
will paint it with Rustoleum brand hamertone paint intended to be put on
rusty metal with no primer. I have used it on rusty metal before on outdoor
steel and after 10 years it still looks new. This paint comes in spray cans
or quarts at the big box stores. I have found it in colors in spray cans but
only black and silver in quarts. Silver can be tinted and gives a slightly
pastel metallic look when I had it tinted as dark green as they could.
73,
Patrick AF5CK
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