It is interesting that I recently ordered the base plate and the bolts from
U.S. Tower for a HDX-589MDPL and this is the original plan. What arrived
was the base plate and six inch and an eighth by twenty seven inch long with
a nut welded on the bottom. Obviously, they were complete with nuts and
washers for the top. The configuration is 2x2x2 using these bolts and nuts.
The plan: is to weld six of these in the pattern and then three more inside
the circle for my HDX 555 which is a 1x1x1 configuration. Using the same
bolts. A lot of the guys let the base rest on 2 by 4's with the tower bolts
inside the box for the cement to surround. My system is slightly different,
we use four inch plate and we weld all the bolts into the pattern at the
same time. The reason for this is obvious -- that I am going to pour the
foundation for the large tower and then be able to replace my smaller tower
with the larger one without foundation problems. Since I am pouring two
foundations, I made a phone call to a friend of mine who owed me more than a
few favors. And by dump truck, he delivered a dozen inch and 3/4 by 4 foot
long highway sign bolts. Interestingly, the bottom of them -- if you can
imagine a saucer plate 2 inches thick by 3 inches in diameter with an inch
and 3/4 threads inside -- my machinist is going to cut them into 2 and we
are going to use the original saucer plates and he will just rethread them
an inch and an eighth for U.S. Tower And weld them all into the same pattern
for the second tower foundation. He is looking at these and he says there
is nothing really special about the steel nor the threads. Obviously, the
total diameter of the bolt is larger than the threads and if someone really
is interested I will get my micrometer out and I'd give you the actual bolt
size. There is probably a couple of ways of holding the pattern solid when
pouring the concrete but I feel far more comfortable doing this as simply
not only do you have the pattern on the bottom holding them, but they are
now all welded together and now the cement becomes one huge block. If they
shear off then I think I would have to go find a new house because obviously
what would shear them off, my house would be missing also. 73 Gene K2QWD
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of Al Williams
Sent: Thursday, September 30, 2004 3:18 PM
To: Bill Turini; towertalk@contesting.com
Subject: Re: [TowerTalk] RE: Tower bolts
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@cypress.com>
To: <towertalk@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
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
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