I have done it two different ways with my last two QTHs on a 100' Rohn 45
tower with flat top section.
1) Tie the mast just above center of gravity to the lifting rope through
the gin pole. Pull it up with a small piece of rope, caribiner, clamp,
etc, tying the top end of the mast to the lifting rope to prevent
flipping. Once the mast is at the top (you will have removed the tie off
point at the top to get the tie off point up to the gin pole pulley). Give
the lifting rope a little slack and lift the mast into the tower
manually. You may want to add a loop around the bottom of the gin
pole/tower and the lifted mast to ensure it doesn't flip on you. It was
surprisingly easy to lift the mast due to the amount of stretch and spring
in the rope when picking it up that last foot or two to insert it. It
didn't seem like I was picking up nearly 200 lbs to insert it in the
tower. Adrenaline maybe?
2) Insert the mast in the first two sections of tower and tilt them up. I
use pier pin bases so this is easy. Build the tower and then pull the mast
up through the center of the finished tower. As soon as you can get it
through a thrust bearing or rotor plate you can put a clamp on it and hold
it there until you get a come along on it for final positioning once the
antennas are on and you are ready to insert the rotor. I have always used
a comealong to jack the mast up as I install each antenna starting from the
top. Rotor goes in last after everything is installed and you let the mast
assembly back down into the rotor.
The key is always thinking it through and making sure you know when you may
not be above the center of gravity when you have grabbed that mast and risk
having it flip on you. A nearly 200 lb wiper that will easily clean any
climbers off the side of a tower.
Looking at that pile of steel in the barn and I can't help but wonder if I
am finally getting too old for this crap. I paid the pros to take it down
for me when I moved last but I was under time constraints and couldn't do
it myself by the time I had to be out of that QTH.
Earl
N8SS
>
> >
> > Greg N5IF wrote:
> >
> > I've a 22ft chromoly mast and am wondering if I will get this installed
> at
> > the moment (without a crane).
> >
> > Right now, I have 40ft of R55, and I thought I would raise the mast and
> > drop it into the yet to be completed tower (easier to do in my mind) vs
> > trying to stab it into the bearing when the tower is completed.
> >
> > How have others dealt with a 22ft mast, when you have a 12ft gin
> > pole.......what am I missing to get this done?
> >
> > Greg
> > N5IF
> >
>
>
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