A 70 ft. ham tower 2 blocks down the street from me came down about a
week before Christmas in a windstorm we had here in Western Washington.
Was just a pile of scrap steel and aluminum when I saw it a couple of
days later. Fell on his roof and that of his neighbor. He had just
installed a new Force multiband yagi on it last summer. The tower has
been in place for at least the last 7 years that I have lived in the
area and probably a lot longer than that, maybe up to 20 years.
I stopped to chat with him and he said one of his tower guy earth screw
anchors had totally disintegrated in the ground and the guys broke free
in the wind. The other two anchors were like new he said. It is a
mystery why one anchor virtually dissolved or rusted out and the other
two were ok. He wonders about potentially corrosive soil or electrolytic
corrosion. The anchors are the standard earth screw kind used by the
power companies. Fortunately, no one was injured and he said insurance
will cover the replacement cost.
Is screw anchor corrosion a typical problem? How does one keep tabs on
this? Can it be detected or prevented?
Jack
KD7OE
Des Moines, WA
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