Thanks to advice from K7LXC, I put up my 80' R45 last August by the latter
method. Two preassembled 40' sections, first one hoisted onto pin (with guys
hanging free), hook up and pretension guys, then climb tower, unhook slings,
wait up there while the second section was hoisted, bolt the second section
onto the first section (again with guys hanging free), have crew connect and
lightly pretension top guys. ONLY THEN climb to top, disconnect slings, then
relax and wait for antennas to be hoisted up to you. Note that only one
person needs to climb, and only once. My 23' mast was put in place in the
top section before hoisting it. With good planning and slow careful work by
myself and a 2-man ground crew (and a savvy old crane guy who knew what he
was doing) it was a piece of cake, took just under two hours, and nobody
ever felt he was in danger (especially me, who did it this way to avoid
having my wrinkley old butt climbing ANY unguyed sections). Total crane cost
(100-footer) was about $280, and worth every single penny. I do not believe
I would hoist the entire thing in one shot, but it's your tower. Also very
highly recommend placing a good quality (non-Chinese) comealong and Klein
grip at all three guy anchor stations. Train your ground crew in how to use
the comealongs and grips. Don't laugh, it's not immediately apparent if
you've never used one, and guy tensioning is a bad place to screw up. :-)
Final tweaking becomes a near trivial job, assuming you have the slick
little Loos tension gauge from Champion. By judiciously using the
comealongs you will be able to make the center and top of that tower do the
boogaloo if you want to, so don't worry if the top section is not perfectly
straight at first, tweaking it in will be easy. Hope all goes well, keep us
posted.
73, Jerry W5KP
----- Original Message -----
From: "Bill Ralston" <n7vm@lgcy.com>
To: <towertalk@contesting.com>
Sent: Friday, February 01, 2002 11:53 AM
Subject: [TowerTalk] Rigging (crane) question
>
> I'm putting up 100' of Rohn 55 (two level guying on pier pin). I am
> thinking of using a crane to put it up for both time and safety
> considerations. Cost is pretty minimal (about $100/hour - the same rate I
> bill out my consulting time at!). After talking with a crane company, we
> think the easiest way to go might be the following:
>
> - Assemble all 100' of the tower on the ground
> - Install rotators, mast, guy anchors, and guys (let guys drape down)
>
> Pick the whole mess up from the top end with the crane, set it on the pier
> pin, set and tension the guys, then climb the tower and disconnect the
> crane.
>
> Use the crane to place the three antennas.
>
> The total weight of the tower with rotors and mast etc. is well within the
> capacity of the crane. I'm a little bit worried about the bending on the
> tower. I recall seeing that you aren't supposed to hinge up more than 30'
of
> Rohn 25, 40' of Rohn 45, and 50' of Rohn 55, but I can't find it anymore.
>
> I tried to do some calculations, and it looks marginal to me, but I don't
> really trust that I know what I am doing.
>
> An alternative would be to lift up just the first 50' of tower, guy it,
and
> then use the crane to stack 1 or 2 sections at a time on top of that. (I'm
> hesitant to try and get too long a piece of tower lined up property on the
> lower part). Obviously this would take quite a bit more time (both for
the
> crane and for the tower climber).
>
> Any comments or actual experience?
>
> 73 de Bill n7vm@lgcy.com
>
>
>
>
>
>
>
>
> ________________________________________________________________________
> Where do you get ICE bandpass filters & beverage matching boxes? The
> same place that pays for the hosting of this list: The eHam Store.
> Order online at http://store.eham.net.
> -----------------------------------------------------------------------
>
> -----
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>
>
________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
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