[TowerTalk] Adjustments to Tower Base Pier J-Bolts
jim.thom at telus.net
Mon Jul 24 10:20:44 EDT 2017
Date: Sun, 23 Jul 2017 19:41:20 -0500
From: "h.duck" <h.duck at ameritech.net>
To: "Dick Green" <dick at mailgreen.us>, "Paul Christensen"
<w9ac at arrl.net>, "'Grant Saviers'" <grants2 at pacbell.net>,
<TOWERTALK at contesting.com>
Subject: Re: [TowerTalk] Adjustments to Tower Base Pier J-Bolts
What you just said, I was going to suggest next. If possible test the fit
with the bottom section by itself.
<Regardless of what you decide to do, I'd sure want to check the fit of the
base before and after any adjustments and before bringing in a crane. Can
the base section be disconnected from the rest of the tower for a test? f
it's too tall/heavy for you and a helper or two to lift (e.g., a 20-footer),
you might be able to lift it into place with a bucket loader.
73, Dick WC1M
## You folks realize this is a 140 ft tall free standing Pirod ?
Bottom legs will be a minimum of 2.5 inchs..and solid. Typ
2.5 to 3.0 inches. Pirod is known for its solid legs. Im guessing
base is 6-8 ft across, each face..maybe more. Dunno if its in 10 or
20 ft sections. Either way, the very bottom section is gonna weigh
one helluva lot more than you think. 1000-2500 lbs.
## Those J bolts he is using, are massive... at 1.875 inchs across, with
12 inches sticking above the concrete. Paul did not say how many are used on
each corner, probably at least 4. They are not gonna budge, whether a sledge hammer, or
hydruaulic jack used...or trying to crank up on the lower nuts, trying to raise the template...
and then trying to bend the J bolts, not gonna happen.
He did not say what the template is made of, nor how thick it is. Paul did note the base section,where
the J bolts pass through are 3 inches thick. How the heck you are going to elongate the oem 2 inch
diam hole in the base section is beyond me. Even if its possible, you will want to spray it asap with some
cold galvanizing compound...since you just ripped the oem zinc off.
## those J bolts typ come in either 36 ksi yield strength, or 53 ksi, or 103 ksi. Color coded
at the very top is how portland bolt does it. Blue-Green- Red for the 36-53-103 ksi material.
I used the 103 ksi, Red, for my 12 x 1.125 diam anchor rods for the HDX-689. Rods are 6 ft
long, and a 6 inch thread on each end. 9 inch square steel plates on the bottom of each group
of 4 x rods. That 103 ksi material is rock hard stuff to work with.
## Paul calculated 3 inchs of exposed thread above the top nuts. A 1.875 threaded J bolt will require
at least a 3 inch wide socket....and super deep..and also a 3 inch open end wrench to hold the nuts below the
tower base. Each of the nuts are 2 inches thick, so any socket will have to be at least 3+2 = 5 inches deep.
Those sockets will only come in .750 or 1.00 drive variety.
## Thats a monster tower project he has taken on....and two of em. It would almost require a small crane to
assemble the tower in the horizontal position..then a monster crane to lift it upright to the vertical position, then
lift, swing..and lower onto the myriad of 1.875 inch base bolts. This is where you want multiple deep sockets,
open + box end wrenches, tq wrenches, loads of help, etc. Both my 1.625 and also 1.8125 sockets, both deep types,
are the .750 drive variety. I used a .500 to .750 drop in adaptor, so I could use my .500 tq wrench and also my
.500 corded electric and also .500 air impact wrenches. You can also buy cordless tq wrenches with up to 600-700
ft lbs of tq. Great when the commercial AC power goes out.... or you are up the tower...and dont want to drag an
extension cord ....or air hose with you.
## IMO, I would test fit the very bottom section by itself, onto the 1.875 bolts. You may well be able to cut as much as
3.5 inches off the tops of the offending threaded rods. Nuts below the tower base assy, need only be .5 inch above the
concrete. At that point, the rods will be 8.5 inches above the concrete. 8.5 / 12 = .71 .71 x .125 = .089
So if you do have to elongate the offending anchor base holes, it will not be very much, .089 inch.
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