On Thu, 22 May 1997 12:14:56 -0600 al511@freenet.uchsc.edu (Robert Neece)
writes:
>
GIN poles are designed for a vertical lift ONLY. I have heard of people
bending
the Rohn GIN pole when using it to pull up large Yagi's along a trolley
or for
supporting the trolley rope itself.
GIN poles that rest on the steps would exhibit a large mechanical
advantage,
multiplying any horizontal force applied to the top of the GIN pole to
the step
welds due to the long lever arm versus the short step spacing. Such an
application could break a weld if a sufficienty large load was applied.
I find that the tower MAST is a better and usually stronger support for
the
trolley and pullup ropes used to install the antennas.
de Tom N4KG
>
> I've thought about this just a bit. Perhaps the rungs
>are strong enough to support the *vertical* weight involved.
>Sometimes, though, I use a gin pole for horizontal (or nearly
>horizontal) loads, such as with a trolley system for elevating
>yagis. I am particularly reticent to apply force to Rohn
>cross braces in a horizontal vector, even if the braces could
>safely support a dead vertical lift. Just a thought.
>
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