Interesting question/discussion of mast pipe and mounting of antennas. I
just had a recent experience that might help.
US Tower tested my tower with 500 lb weights. They put a short mast in and
loaded it with weights. Tilted it up and then raised it.
I have broken a UST HDX589 in a straight line wind this June. It broke
just about one foot above the 3rd section. Each section is 21 feet and the
overlap is recommended to be 4 feet. My tower broke because it was too
much load for the wind that hit it. I have an identical tower about 75
feet away with a MonstIR and 6M9 that had no damage but were overlapped by
5 feet. Here are some visual images of what to avoid...
http://www.k9ct.us/Photos/wind%20damage/index.htm
Normally, none of these towers would have been up. This was a fluke wind
storm and I thought 30% chance meant I could sleep without worrying about
it. Wrong....
I have the Chromoly mast plus enough hardware to weigh the tower down. I
would say that the farther you go up the mast with wind area, the more
leverage you are putting on the sections. Twisting does not seem to be as
much of an issue.
BTW, this is an expensive repair. You got to get a crane in your back yard
to lay it down. Plus pay UST to drive to your house with new sections.
They did a great job plus restrung my other tower while they were here.
State Farm Insurance covered this repair under the accessory buildings...
10% of your house value. You might want to check to see if that will cover
repair of your towers and antennas. So far I have spent over $15,000 and I
am not done.
This may be way too much information...but this is tower talk and I
thought it would amuse some in the group.
YMMV
73, Craig K9CT
PS...I learned alot about US Tower setup and adjustments.
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