--------- Forwarded message ----------
From: Donald L Kerouac <k9nr@juno.com>
To: towertalk@contesting.com
To: <towertalk@contesting.com>
Date: Thu, 6 Dec 2001 10:52:27 -0600
Subject: Television Tower Topples Very Heavy Antennas
Believe it when they say some broadcast antennas weigh many tons...they
do. I've worked in broadcast engineering many years and there is some
truly massive steel "up there." However, rarely does a guyed tower fail
because of the weight of the antennas. Invariably, "natural" failures
are a result of excessive wind loading. Adding even one inch of radial
ice will severely compound this problem.
Some years ago, at an SBE convention in Houston, I toured the Senior Road
Tower complex. A 2,000 ft. behemoth built to accommodate several 100KW
FM's, a 5MW UHF TV and countless communications antennas. It's built to
do the job in an area where hurricanes sometimes visit. It's quite
something to stand at the base and consider the enormous column load
consisting of the dead weight and the vectored down thrust of the guys.
The top guys are about 1/2 mile long, weigh many tons each and have
massive hydraulic dampeners to keep them from galloping in the wind. You
can imagine the forces such guy assemblies could apply to the structure
if wildly oscillating in the wind.
Some of you may recall when this tower was originally erected about 20
years ago. It collapsed, killing several workers and destroying the
building underneath. Since the tower was being topped off, a camera crew
was taping the whole thing for posterity. As memory serves me, the tower
was at full height and the many ton UHF TV antenna was being hoisted into
position. As I recall something in the rigging broke and the heavy
antenna fell, breaking through guy wire assemblies on the way down. I
believe four men rode the steel to the ground. I may be a bit fuzzy on
the details. It's been a while since I was down there. It's a chilling
video to view.
The site was cleaned up and a new structure was erected and stands today.
It's an incredible installation to tour but not open to the public.
Don, K9NR
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