I posted this to Towertalk in November of 1996:
----------------------
Scary Story
It was not a typical balmy afternoon in Yuma, Arizona on Friday.
There was a cold front approaching from the north, which was
kicking the wind up to about 30 mph. I happened to glance out
the back window and noticed that one of the guy wires on the
48' Rohn 25 foldover seemed to be vibrating more than usual,
so I went out to investigate. The tower is four-way guyed, using
the recommended Rohn GAS604 earth augers to secure the guy wires.
The vibrating guy wire seemed a little loose, so I began to tighten
the turnbuckle. The guys tightened up momentarily, but then went slack
again! The wind was blowing pretty good at this point, and I was
horrified to realize that the earth auger was pulling out of the
ground! There is no way to get a vehicle into the back yard to serve
as a temporary guy support. I immediately released tension on the
opposing guy wire, trusting in Jesus and Rohn's conservative
engineering to keep the tower standing. There is about 17 square feet
of antennas on top of the tower. Naturally, the wind was blowing
in the worst possible direction.
I got on the phone, and found the one and only source of earth
augers in town, a farm supply store a few miles away. I got their
largest one, about 4' long, painted, not galvanized, with a 5"
diameter
auger on the bottom. I screwed it in next to the defective one,
transferred the guy wires, and tightened them all up.
The defective earth auger could then be twisted by hand, but
I had to tap it with a hammer to get it out of the ground. What
came up was a scaly, crusty, two foot long rod, rather than Rohn's
four foot long rod with a 6" auger plate at the end! The end of the
rod had a pointy piece of metal that looked as if it had been
stretched too far. I guess that corrosion had eaten through the
5/8 rod, to the point where the remaining metal couldn't support
the tension, and then it just stretched like taffy and pulled
apart.
The augers have been in place since 1978. They looked perfect
above ground. Even below ground, it was hard to tell whether
the crusty stuff was dirt or corrosion. Looking at it more
closely, the galvanizing had eroded off, and rust had penetrated
to a depth of about 1/8 inch all around.
The moral of the story of course is to routinely inspect all guy
anchors. I remember reading that advice before, but of course
problems always happen to the other guy, and we don't need to
worry about corrosion here in the desert! There's nothing like a
little
personal experience with a Significant Emotional Event to drive a
point
home! Needless to say, I will order four new anchors from Texas Towers
on
Monday. It _can_ happen to you!
----------------------------------------------------------
I remember that someone (Rauch?) suggested at the time that the guy
wires should be insulated to keep currents down. The new anchors had
already been installed before that suggestion was made, and I never
did go back and retrofit the guys. I think I will get four new anchors
now and convert the lower guy set to Phillystran at the same time. The
upper set is already Philly. Then I'll try shunt feeding the tower.
I'm 62 now, so if it all falls down when I'm 80, I probably won't even
notice!
Dave Hachadorian, K6LL
Yuma, AZ
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