[TowerTalk] tower base bolts

[Paul Christensen]

Back in July, I reported on a problem I had with a 140-ft. self-supporting
Pirod tower.  Thanks to the efforts of a couple local area farmers, they
used the hydraulics from two tractors to bend six base bolts toward the
center of the base by about one-quarter-inch.   

 

Recall that the problem developed during the pour: The concrete came out of
the chute faster than normal as darkness was setting in.  Even with a
template to hold the bolts stationary, the force of the pour pushed the
bottoms of all 6 ft. bolts outward, meaning that the tops of the bolts were
all pointing inward by a fraction of an inch.  But that fractional error was
huge for the tower base.  

 

After ruminating five months on the fix, the template is now off the bolts.
We've always known that if the template can come off, then we know with
certainty that the tower will go on the bolts.  Here's why: the tower base
bolts and the template holes are precisely 1-7/8 inch diam, but the tower
base holes are exactly 2-inch in diam.  It doesn't seem like a lot of wiggle
room until you've tried placing and removing the template.  

 

Fortunately, the template for the 100-ft. tower came off the bolts without
issues.  "Crane day" is in three weeks.

 

Paul, W9AC