Plus it would be dangerous to be outside cranking down a tower during
tornado or microburst and it may jam from the extreme side wind force.
I would not want to rely on having to crank down a tower to survive
normal heavy winds however in hurricane prone areas crank-up towers
may be good option. Most of the guyed towers that I know of in St
Croix fell down during Hurricane Maria and most crank-up towers in the
down position survived. Hurricane paths are predicted days in advance
so there is plenty of time to lower a tower and even remove the
antennas if desired.
73,
John KK9A - WP2AA
Bob KQ2M wrote
I don’t know how long is required to crank down at 89’ crank-up at
full extension but I would suspect that it is at least 90 seconds.
At this qth, when a Tornado or macroburst/microburst winds are
approaching, I get about 30 seconds warning from the oncoming “roar”
of wind crashing through the trees. The noise is loud, distinct and
unmistakable. If at that exact moment I started to crankdown an 89’
tower, I doubt that it would have been lowered enough by the time the
winds arrived to make it the rest of the way safely. If it took me a
minute or two to get to the station to lower the tower, I’m sure that
it would be already too late. That’s probably what happened with the
guy with the tall tower, anemometer and winch.
The other issue with such violent winds is that they are usually
hurling debris as they come in. All it would take is one solid branch
or piece of something wedging into the tower at a strategic spot to
stop the winch dead in its tracks. Game over for the tower. BTW,
this is one reason why Tornados are so dangerous – often significant
damage is caused to objects by debris picked up and hurled somewhere
else outside of the funnel.
Bob KQ2M
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