[Towertalk] Pinning Mast to Rotator
Bruce B. Sawyer
zf2nt@candw.ky
Mon, 21 Oct 2002 14:04:55 -0000
I'm now in the process of repairing the damage to my antennas caused by
Hurricane Lili a couple of weeks ago. Little Cayman took a direct hit from
that one, so my little antenna farm took quite a beating. Among other
things, the mast on one of my antennas was twisted around about 100 degrees
in the rotator mount. There was only one antenna on it--a Bencher Skyhawk,
which is supposed to be wind-balanced. I was just about to go drill a
through-hole in the mast so I can put a bolt in and pin it to the mast when
I started wondering about the wisdom of doing that, and wonder if others
with more experience of taking towers through hurricane force winds have
thoughts on the subject. Had the mast been pinned to the rotator when Lili
struck, the yield point likely would not have been the mast-to-rotator
connection. With a large enough moment, I wonder what would have yielded.
The top section of my Rohn 45 tower? The U-bolts on the rotator plate? The
rotator itself? Whatever would have been forced to yield, I'm certain it
would have been more time-consuming to fix, and obviously more expensive,
than repositioning the mast in the rotator. On the other hand, maybe it
would be that nothing would have yielded, and now I'd have one less repair
item on my to-do list.
Thoughts?
Bruce, ZF2NT
Little Cayman Island