bob finger wrote:
> Steve Maki wrote: Sure.
> Assuming a 100' tower, attach a c. 60' cable to the tower at the 100'
> level AND the 50' level...
> Now this sounds really dangerous! Might work fine but how do you
> control the movement of the tower bottom while the hook is slipping
> upwards? Crane still has to reach above the tower top so not sure what
> the advantage is to this method. I'm no professional rigger but
> thinking about doing this make the hairs on the back of my neck stand
> up. Sorry, I'm not convinced yet. 73 bob de w9ge
The advantage is that at the critical beginning of the lift, you have
lift at the middle of the tower, and at the end of the lift, you are
holding the tower at the top, so it hangs mostly vertical. Wasn't
that the whole idea?
I admit, an inexperienced crane operator can make the raising of a
horizontal tower to vertical a little hair raising. I'm used to very
good operators, who make all this look like child's play.
That said, I wouldn't worry about lifting 100' of R45 from the top,
but I've used the slipping basket method with no problem.
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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