Gary, I should have realized that you have plenty of experience; my
apologies for inferring otherwise!
If your guys are Phillystran using the rope style block may well be
adequate for initial tension but if all steel, probably not.
At the risk of stating the obvious and to minimize crane time, you can
start out with moderate guy tension and fine tune guy lengths and tension
later. The tower might have some lean and/or not perfectly straight but it
will
not collapse while finalizing the guy tension adjustments.
In any event, you will be doing a lot of back and forth running. Hopefully
you will have some help but it can be done alone. Personally I would
install all of the lower grips about 80% to allow easy repositioning as needed
and then complete grip installation as the last step. I can't imagine doing
this without a come-a-long tool.
This sounds like a really fun project and I know you are looking forward to
using the system.
73,
Gerald K5GW
In a message dated 10/12/2016 6:54:40 A.M. Central Daylight Time,
rxdesign@ssvecnet.com writes:
Hi Gerald,
Actually I’m use to using grips and have done many towers... I’ve done
it all before – I’ve just not used 5/16” and don’t know if in situ I’ll be
able to estimate it accurately. I have 3 older grips that will function as
the ‘connection point’ for pulling each guy. What I don’t have is three
come alongs. I have instead, what I used on the 1/4” guys, are three ... I’m
not sure what you’d call them... they’re rope and there is a block with a
rotating cog in it that locks on the rope when you pull it through adding
tension in the process... I don’t know if they’re able to handle any more
than about 150# of pull – so there is my question ... if I get to that
amount of pull will the turnbuckles have enough room to pull them from there
to
full 1100#? I’ve Google searched to see if there is a chart of initial
tension and how fast say per inch of displacement of the turnbuckle the force
goes up ... its obviously a non-linear curve.
and I’m having trouble getting people to just lift and stage the antennas
let alone with any experience at the guys so its looking more like I’ll be
running from one to the other (140’ out from the base and not a direct shot
from one to the other). I’ll get my work out.
thanks Gerald.
Gary
From: _TexasRF@aol.com_ (mailto:TexasRF@aol.com)
Sent: Tuesday, October 11, 2016 9:15 PM
To: _rxdesign@ssvecnet.com_ (mailto:rxdesign@ssvecnet.com) ;
_towertalk@contesting.com_ (mailto:towertalk@contesting.com)
Subject: Re: [TowerTalk] questions on the use of a man-bucket and guy
tensioning 5/16"...
Gary, you are on a steep learning curve! Most installers use a come-a-long
to pull the initial guy tension and hold the guy in position while the
lower guy grip is installed.
If you install the grip about 75% it is relatively easy to remove and
reposition the grip. Once installed 100% you likely will destroy the grip
trying to remove it. Once you are sure of the proper position it is easy to
complete the grip installation.
After the first few grips are installed you will get the hang of it and
get the position correct on the first try.
If you have a man on each anchor it will go a lot quicker but you will
need three of the come-a-longs for best speed. a half installed big grip makes
a quick method of attaching the come-a-long to the guy. Some installers use
a "pork chop" (I forget the actual proper name) to grab the guy cable;
perhaps you already have three of these.
73,
Gerald K5GW
In a message dated 10/11/2016 7:18:06 P.M. Central Daylight Time,
rxdesign@ssvecnet.com writes:
Hello,
This is directed at those that have had direct experience with the use of
a crane and a man bucket.
My antenna/tower project, at least the major part of it (one of the two
towers) is finally getting close to being done. I’ve ordered the crane for
the end of next week ... so I can get a man bucket for an additional $150.
There are 6 large yagis to be installed – well 5 and a rotary dipole for
80/75 which is also BIG in that regard ... there’s currently 74’ of tower up
on the K0XG rotating base and 2 rings ... I’ve built another 60’ of tower
with the second ring on it ... that will go up first and the top section of
guys installed.
then I have 14’ of tower that will already have mounted on it (I hope) the
rotary dipole at the top and a 5 element 50’ boom 20 mounted just above
the leg of the tower (R55). That whole assembly will go up as one and thus 2
antennas will be finished once this is bolted in to place.
Then there are 4 yagis to go up along the height of the tower from 124’
down to 45’. I had planned on just having a guy on the tower stuff (no choice
there of course) ... and then have him climb down the tower as we go from
the top down with the 4 remaining antennas 124’, 90’, 75’, 45’. This
means I’ll have to lash up the antenna on the ground to the crane hook and
then
of course the crane will raise it up to him where he can hopefully bolt it
in place (2 plates on the boom already in place for the boom to tower
mount).
But the guy that is doing the climbing is saying the man bucket will make
putting the antennas up easier. Having never used one I’m writing to get
the comments of those that have used one.
How is the antenna ‘held’ to the man bucket? And whatever that is does
that get in the way of mounting the antenna when at the tower. I.e. you have
the side rails of the man bucket that would be ‘hitting’ the tower – will
the antenna ‘move in” to position and still be SAFELY held until bolted in
place?
Is it really any faster?
I assume it could be considered safer as the guy would be in the man
bucket and not climbing the tower but obviously one expects whomever that is
to
be careful and always be strapped in when climbing ...
thoughts please?
And on another note: the top guys are 5/16” mixed with 11200# philly (50%)
... how much tension do you need to pull out of the ‘free’ cable before
attaching it to the turnbuckle? I’m worried about not pulling enough and
having to redo the big grip ... on the bottom set of guys (the bottom 2 sets
are 1/4”) I managed to do just that – I pulled too much and had to redo the
big grip. Of course on the 5/16” the worry is more that I won’t pull
enough and will run out of turnbuckle adjustment space. Put another way: how
fast does the tension go up as one adjusts the turnbuckle? If the turnbuckle
has 12” range – will that pull up even a relatively loose guy to full
tension of 1100# before running out of adjustment room?
Gary
K9RX
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