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[TowerTalk] Adjustments to Tower Base Pier J-Bolts

To: <towertalk@contesting.com>
Subject: [TowerTalk] Adjustments to Tower Base Pier J-Bolts
From: "Jim Thomson" <jim.thom@telus.net>
Date: Mon, 24 Jul 2017 07:20:44 -0700
List-post: <mailto:towertalk@contesting.com>
Date: Sun, 23 Jul 2017 19:41:20 -0500
From: "h.duck" <h.duck@ameritech.net>
To: "Dick Green" <dick@mailgreen.us>, "Paul Christensen"
<w9ac@arrl.net>, "'Grant Saviers'" <grants2@pacbell.net>,
<TOWERTALK@contesting.com>
Subject: Re: [TowerTalk] Adjustments to Tower Base Pier J-Bolts

<Dick,

What you just said, I was going to suggest next.  If possible test the fit 
with the bottom section by itself.

Howard


<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. 

Jim   VE7RF 
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