[TowerTalk] RE: Tower bolts

[Al Williams]

I don't know if the UST supplied bolts for the HDX572 are identical or
similar to those used for the TX-472 but if they are;
they are not ordinary straight bolts but rather are in the shape of a J.
The bottom of the J is only 27" overall with only 22" embedded
in the concrete.  The foundation stress analysis claims a Pullout
Capacity = 258,490 pounds and states it is OK.  I can't determine
anything in the tower stress analysis that shows what the pullout stress
is.  Perhaps someone can explain what benefit is obtained by having the
bolts bent into a J  in the concrete.

Also, is the UST supplied stress analysis valid if the J bolts are
replaced with straight bolts?  What effect would that have on a building
permit and an insurance claim if the tower failed?

k7puc

----- Original Message -----
From: "Bill Turini" <wtu at cypress.com>
To: <towertalk at contesting.com>
Sent: Thursday, September 30, 2004 10:53 AM
Subject: [TowerTalk] RE: Tower bolts


> I have a TX-472 tower that I bought used. I called a local bolt firm
> that caters to the local maritime and construction trade, told them
the
> bolt specs and they said "no problem".  The first time they charges me
> $16 for three bolts (and nuts, washers, and lockwashers). The second
> time (8 years later) the price went up to $34 or so, but I had the
bolts
> made 4' long, with 6" of thread.
>
> They also supplied ASTM-A36 bolts and nuts for mounting the tower to
the
> base fixture. Any place that deals with construction that puts up road
> signs should be able to help.
>
> Bill  KA4GAV
>