I see the "fall zone" issue as more of a political or social issue. In
every city there are telephone poles, billboards, streetlights, traffic
signals, flagpoles, etc., all within the fall zone of neighboring
properties. Those are fully accepted by society and rarely questioned for
fall safety. But as soon as we put up a ham tower we freak out about
towers falling over.
For some reason we accept wooden telephone poles carrying 12 kV overhead as
"safe" despite the fact that the engineering of telephone poles is far less
thorough than for ham towers. There's no engineered foundation, just a
hole drilled in the ground based on rule of thumb (typically 10% of pole
length plus 2 feet). Wood, especially buried wood, is far more prone to
degradation than galvanized steel or aluminum.
I'd argue that the failure rate of wooden poles carrying overhead power is
far higher than that of ham towers.
A properly engineered and constructed ham tower can be made just as safe as
any other vertical structure. There is no logical reason to single them
out for "fall zone" concerns.
73 Jim K6OK
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