[TowerTalk] Adjustments to Tower Base Pier J-Bolts

Wayne Kline w3ea at hotmail.com
Sat Jul 22 14:03:04 EDT 2017


  IMO  the 1/8"    .120 off center and the larger base hole with it's  .060  clearance to the center line C/L

  I would use a die grinder and elongate  the offending  two  base plate holes .

Wayne  W3EA

From: TowerTalk <towertalk-bounces at contesting.com> on behalf of Paul Christensen <w9ac at arrl.net>
Sent: Saturday, July 22, 2017 9:47 AM
To: TOWERTALK at contesting.com
Subject: [TowerTalk] Adjustments to Tower Base Pier J-Bolts

Got a nasty situation here that needs some brain power to resolve.  Earlier
this year, I poured two base piers for a pair of Pirod self-supporting
towers.  The 140 ft. tower base has the problem.   Unfortunately, the base
J-bolts on two of the three equilateral triangle points are bent inward,
toward the base center by 1/8".  That 1/8" may not seem like much, but it
is.  In fact, the template used during the pour cannot be removed.  During
the pour, the J-bolts were double-nutted, one on top and the other below the
template.  Still, the force of the concrete pour managed to push out the 6
ft. J-bolts.  As that was settling, I quickly moved the crew to the other
tower as sunset was minutes away.  I did not go back and take a level to the
bolts, thinking the template would keep them perfectly straight.

Each 6 ft. bolt is exactly 1-7/8" in diameter.  Each protrudes 12" above the
concrete surface.  Moving these huge bolts even 1/8" will take a Herculean
effort.  The template holes are the exact same diameter and made that way to
minimize shift of the type that occurred anyway.  The tower base section has
mounting holes that are exactly 2.0" in diameter.  So, there's just a small
amount of wiggle room.  If we can get the template off, then I know that the
tower base will absolutely go on without trouble.

Some options:

1) Use an oxy-acetylene torch and apply heat at the point where the J-bolts
exit the base, then pound with a sledge hammer.  Trying it now without heat
is futile; we've tried and the bolts are going nowhere.  I have no idea what
heating will do to the strength of the J-bolt.

2) Use a telescoping hydraulic cylinder (a.k.a.  hydraulic ram jack) to push
the two J-bolts against each other since they are both leaning in by the
same amount.  What I don't know is how much adjusting precision I'll have
when expanding the cylinder.  Do these things move in very small increments?
What cannot occur is the cylinder "jerking" the bolts to anything beyond
1/8".  These cylinders are capable of pushing 30,000 lbs. and are typically
used on large earth-moving front loaders.

I'm open to any other ideas.

Paul, W9AC

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Rudy
Bakalov via TowerTalk
Sent: Saturday, July 22, 2017 9:10 AM
To: TOWERTALK at contesting.com
Subject: Re: [TowerTalk] 80 M 4 SQUARE MODELING

I am in the exact same situation- 95' tower that I plan on using to suspend
wire elements from the top of the tower.

I assume THERE WILL BE interaction between the 4SQ and the tower. What I
have been wondering is how mechanically reliable this setup is compared to
elements made of aluminum tubing. Any thoughts on this?

In addition, I have been wondering if the wire will stretch over time
thereby changing the resonant frequency of the elements. Perhaps CAT5 might
be a better option for the elements as it is less likely to stretch?

Rudy N2WQ

Sent using a tiny keyboard.  Please excuse brevity, typos, or inappropriate

> On Jul 22, 2017, at 8:43 AM, StellarCAT <rxdesign at ssvecnet.com> wrote:
> Now that I have finished my tower for 40-10 meters I need to start my next
project.  I'm limited to the one 90 foot tower I have by county code.  I am
planning on running 4 ropes from the last guy point (84ft) to install a wire
4 square for 80 meters.  Wires would be suspended vertically from the ropes
in a typical 4 square pattern using Comtek switching.


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