Rich,
I'd like to offer one slight modification to my aforementioned alternate
method, not because there's anything inherently wrong with hanging a
whole tower from a crane, I've done that many times. It's just that I
think there's a faster way.
It depends though on where your current top set of guys reside. If they
are just below your top section, than picture this:
1) Assemble the four new sections horizontally on the ground, complete
with a new set of (top) guys attached.
2) Lift off the top section WITH mast and antennas and place at a
predetermined ground location where it can quickly be stabilized by any
of a number of methods.
3) Lift the 40' of new tower into place, bolt on, pull out the already
attached new guys and attach to anchors.
4) Lift the top section with antennas back up to the top, and bolt on.
5) Done.
Well except for all of the niceties :-)
-Steve K8LX
On 11/18/2013 2:35 PM, Richard Thorne wrote:
Lot's of good thoughts fellas.
I would have all the prep work done or ready to be done prior to the lift.
To answer a couple questions:
1 - Guy spacing is not an issue, the anchors are already out the required
distance and have more than enough concrete. I had planned on side mounting
and wanted to be sure I had the clearance for turning the beams.
2 - I plan on splicing guy's with thimbles or insulators. The current onces
are a combination of Philly and EHS. Once the crane is attached I can remove
the guy's from the ground anchor and splice the required length and I'll be
ready for the re-install.
3 - I will build the new 40' of tower horizontally, install the guy bracket
and guy's and use a second smaller crane to put it place. If I a 42'
terrain forklift is cheaper, I'll go that route. It doesn't take long to be
sure the tower is plumb and tension the guys.
4 - Tag lines will be a must to keep the tower from twisting. A non-windy
day will be the trick. Around here (the 3d windiest city in the USA), it's
difficult to plan for a non-windy day, but it can be done.
The crane guy's I use are pretty good and have a good idea what needs to be
done. Lately they've been installing the great big wind mill's here in the
panhandle
When I originally installed the tower, the first 40' was installed with a
42' terrain fork lift (my neighbor was using one so I borrowed it for an
hour). The guy's were pre-attached. I just left plenty of extra length on
the guy's so I had some working room when they were attached to the
turnbuckles. Then the big crane came and we installed the top 37' the same
way. I even pre-installed the rotor, mast and coax cables. We just lifted
it in place. The tower stayed fairly vertical and it was easy for the
rigger to attach the top portion to the bottom portion.
What has changed in this equation are the antennas. It would just make
things so much simpler and consume less time if I could leave the antenna's
in place. With all the prep work I'll bet I can get this project done in
about 4 hours. The original install took about 5 hours which included
installing the top 37' of tower, tensioning guys and installing two antennas
(using a bucket attached to the crane cable).
I'll post some pic's on qrz.com later this evening of how I recently
replaced the Delta 240 with a Delta 240/230 with the crane/bucket.
Rich - N5ZC
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