[Towertalk] Tower base "solution"

[Guy Olinger, K2AV]

Tucked away in many small corners of the specifications for bases and
such, are such quaint phrases as undisturbed earth, among others. All
of which make the right stuff not quite as "prefab-able" as one might
like.

As to hauling stuff in ready-poured, ready-hardened, ready-reinforced,
and ready-to-go, consider the base to my 80' Trylon self-standing
tower...

11 cubic yards of concrete with embedded base legs and what must have
been 300' of 3/4" rebar. The professional commercial building
foundation guy that my contractor son-in-law brought in to put it
together stated that the undisturbed hardpan (clay on its way to
becoming slate) around the bottom 2/3 of the hole would double or
triple the strength of the foundation against overturning. He
pronounced it non-overturnable in a tornado. Tornado might literally
rip the tower off the base, but the base not going anywhere, for
anybody, ever.

The foundation guy looked at the Trylon spec, decided it was "wimpy",
and ADDED a reinforced cantilever ring and pressure plate around the
top which would require a potential overturning moment to BOTH lift
the main concrete mass upward AND kick the bottom horizontally back
toward the overturning force (sideways into the hardpan). The
reinforced cantilever pressure plate was poured onto undisturbed earth
(actually the top of the hardpan), to disallow downward compression by
the cantilever and force the lift/sideways kick.

Haul THAT ready-made in on a truck.

Here's to constructing two or three times over spec, and sleeping at
night. Here's to engineers that can write specs that actually work.
Here's to doing at least what they say.

73, y'all.

Guy.

----- Original Message -----
From: "Jim White" <k4oj@tampabay.rr.com>
To: "Stu Greene" <wa2moe@firstinter.net>; "Chris BONDE"
<ve7hcb@rac.ca>
Cc: <towertalk@contesting.com>
Sent: Thursday, April 04, 2002 10:05 PM
Subject: Re: [Towertalk] Tower base "solution"


> Chris,
>
> I suspect you are new to this list...
>
> One of the things the moderator, K7LXC, repeats over and over again
is to do
> what the manufacturer calls for.
>
> As a professional I know whaty he is saying - he is simply stating
that
> unless the manufacture calls it out you are open to liability or
lack therof
> down the line when they can state "he clearly did not follow our
> guidelines:...
>
> I also like the idea of a precast block with a bunch of threded
stubs
> sticking out of it....in the shack we have plug and play...in the
yard you
> could have place and play!
>
> One potential downside of course is whether or not you could get a
truck
> into where you want it placed...if so, great - seems it would be
little
> different than planting a septic tank...as a matter of fact I bet
the guys
> would build those would love some of this business...very similar to
their
> existing stuff - dunno how heavy we are talking for the block versus
a big
> septic tank - do not know how many yards go into one of them...
>
> I think the idea is an interesitng one - but - to avoid the
hellacious
> lawyers I suspect it is something whose time has not yet come!
>
> 73,
>
> Jim, K4OJ
>
> ----- Original Message -----
> From: "Chris BONDE" <ve7hcb@rac.ca>
> To: "Stu Greene" <wa2moe@firstinter.net>
> Cc: <towertalk@contesting.com>
> Sent: Thursday, April 04, 2002 9:21 PM
> Subject: Re: [Towertalk] Tower base "solution"
>
>
> > At 02:17 PM 2002-04-04 -0700, Stu Greene wrote:
> > >At 11:09 AM 4/4/02 -0800, Chris BONDE wrote:
> > >>   Maybe you are correct in the engineer but why not have the
engineer
> > >> sign off on the cast in the hole, whcih cold be less
controllable.
> > >
> > >  Are you suggesting that a PE sign off on something which the
> > > manufacturer strongly recommends and which might be required by
building
> codes?
> >
> > Or a building inspector.  How does one know if all has been
> > followed?  There are many horror stories out there
> >
> >
> > >And finally, this is a sarcastic question, why do you impute self
> interest
> > >in the advice a knowledgeable professional installer gave without
> compensation?
> >
> > I take umbrage with the use of 'impute', possibly 'assume' as he
stated
> the
> > response was 'sarcastic'.
> >
> >
> > >Tacky
> >
> > Was this your signature?
> >
> > All I asked was why could not the precast blocks be used?  Steve's
answer
> > was like a parent, "Because!"
> > I have had responses that  state the question, while not put
correctly,
> was
> > a valid one, Steve's answer, a pat and possilbe flip one.
> >
> > I thought that hams tried to think outside of the box, or on the
other
> side
> > of the wall or with a different paradigm, so I asked a question
that I
> > thought might evoke answers not retorts.  If I bruised Steve's
feelings I
> > apologize.  He has made many valid comments, however, this was not
one of
> > them.  Whereas, those comments on my question by Henry, Dave and
Kelly
> were
> > constuctive while critical.
> >
> > best 73, Chris opr VE7HCB
> >
> > >Cheers,
> > >Steve     K7LXC
> > >TOWER TECH -
> > >Professional tower services for amateurs
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
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