The "drilling rigs" mentioned as of late are all designed to dig a
round hole, not a square one. Every tower foundation spec I've seen
(USTower, Trylon, AN Wireless) specs a square hole. There are lots of
building inspectors that won't accept a round hole when a square one
is called out in the manufacturer specs.
It would seem to me that these tower manufacturers need to realize
that the specs they are creating can't be realized very easily by most
amateurs.
On 7/11/05, Jim Lux <jimlux@earthlink.net> wrote:
> At 08:18 AM 7/11/2005, K7LXC@aol.com wrote:
> >In a message dated 7/10/2005 10:39:28 PM Pacific Daylight Time,
> >towertalk-request@contesting.com writes:
> >
> > > The ability to dig an "undercut" hole no doubt depends on the soil. I
> >gave a local concrete contractor the AN Wireless foundation plan, and he
> >said there was no way to dig such a hole. He said the only way to do a
> >pad and pier foundation around here would be to dig the hole the size of
> >the pad, construct a form the size of the pier, then backfill.
> >
> > A couple of comments about the Trylon base design. First, IMO it's a
> >stupid design. I'm sure there's a valid engineering reason to have the bottom
> >belled-out but it's not only dangerous to be in a hole that deep but it's
> >also
> >illegal per OSHA rules to be that deep in a hole without being shored up.
> >This
> >was designed by an engineer in an air-conditioned office that never has to
> >install one of them. In many cases the soil won't allow it anyway.
>
> I seem to recall a recent post describing how there are drilling rigs that
> can produce this kind of hole. That might eliminate the need to have a
> worker in the hole, which as you say, raises all sorts of flags.
>
> The other thing to contemplate is that the base design may have been done
> decades ago, when the risk of inadvertently killing people in hole caveins
> may have been treated a bit more casually. Safety standards DO change,
> after all, and people have been hand digging wells hundreds of feet deep
> for millenia (and, dying in the process, too).
>
>
>
> _______________________________________________
>
> 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.
>
> _______________________________________________
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>
_______________________________________________
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.
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