By tiltup do you mean a full sized tower? I may have misunderstood the
question, but:
No, I'm talking about the typical 21' compressed crankup, (1400 lbs in
this case), lying horizontal, with two bolts at one end for a hinge,
being tilted up, by a cable attached to it somewhere, with the cable
going over some ginpole or raising fixture at some height, then to a
pulling device. If it's a compound pulley situation, it doesn't change
the force at the tower attach point, so that doesn't matter.
The only reason the question caught my eye, is because I use a homemade
gin pole/winch setup, guyed (side and back) with single pull line, for
tilting up my crankups. Have done 3 different installs of HG-70HD which
is similar weight, and a WT-51. I worked out the numbers in my case
because I wanted to know how tall a gin pole I needed, for the
relatively lightweight winch I was using for the single line pull. I
wanted to keep forces low in the system. Including compression of the
gin pole.
I don't have a lifting fixture.
Note that I said I don't understand the pull in this case.
A worser case pull would be just attaching the cable to the tower, and
the other end to the tractor at around 3' and pulling. You can imagine
that's like having a 3' high gin pole, and the initial forces are even
more than I said. I suppose that situation might work if you raised the
end of the tower a couple of feet somehow, before you pulled with the
tractor, but you'd have to work out the forces to be confident.
-kevin
AD6Z
Wilson Lamb wrote:
> Your answer seems to be talking about a tiltup, not a crankup??
> Wilson
> W4BOH
>
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