[Towertalk] 'Toes' of a tower concrete base

[Jim White]

...thank you Slick Willy, and all the lawyers you wrought!

You have broke us all...would love to go into business for myself but there
is no way - FOL









Fear Of Lawyers





K4OJ


----- Original Message -----
From: "Mike Wetzel" <mjwetzel@comcast.net>
To: "David Jordan" <wa3gin@erols.com>; <kr7x@attbi.com>
Cc: <blueis@sprintmail.com>; <Towertalk@contesting.com>
Sent: Friday, June 28, 2002 12:11 PM
Subject: RE: [Towertalk] 'Toes' of a tower concrete base


> Just can't hold my tongue any longer.
>
> You guys with all the concrete and money!
>
> Up until 2000, I had up 4 towers over 100' (Rohn 45 and 25) and only 1 had
> any concrete at all (in 2000 for my Rohn 55G tower for my 80 meter beam
> several local ganged up on me and made me pour concrete).  I stayed away
> from using concrete because of the cost.  One tower used an old Rohn AX
> screw anchor base, 2 use 6" x 6" wood planks/blocks (similar to using a
pier
> pin) (not self supporting) and I used temporary guys.  For anchors I use a
> combination of power driven screw anchors and hand anchors.  Early on I
used
> salvaged guy wire pieces (alum-a weld) from the utility since I broke up
the
> guy wires anyway bought at scrap prices.
>
> I am an engineer (not structural or mechanical) and I did have good help
> that steered me using common sense (that seems to be evaporating today).
> Early on I did have some failures (booms bent, tornado took down a tower,
> etc) but that is part of it, I figured.
>
> One other thing, I used aluminum for masts (engineered) and water pipe (no
> stacking) not expensive Chrome Molly.
>
> I'm glad I'm not starting out now in the hobby today trying to put a
station
> together, because Mr. Safety, Mr. Lawyer and Mr. Manufacturer would suck
my
> wallet dry if I followed all their stipulations to a 'T'!
>
> Mike W9RE
>
> > -----Original Message-----
> > From: towertalk-admin@contesting.com
> > [mailto:towertalk-admin@contesting.com]On Behalf Of David Jordan
> > Sent: Friday, June 28, 2002 10:16 AM
> > To: kr7x@attbi.com
> > Cc: blueis@sprintmail.com; Towertalk@contesting.com
> > Subject: Re: [Towertalk] 'Toes' of a tower concrete base
> >
> >
> > My guess is sales of towers were dropping as the cost of concrete
> > went up...at
> > todays cost the concrete and digging the hole cost more than the
> > tower!  Then ad
> > the cost of a climbing belt and gin pole and the little 50ft self
> > supporting
> > tower becomes a couple thousand dollar project.
> >
> > Enjoy,
> > dave
> > wa3gin
> >
> > kr7x@attbi.com wrote:
> >
> > > Gary:
> > >
> > > IF you make the foundation straight sided at the plan
> > > base dimension (largest size at bottom) you should have
> > > no problems as far as your installation is concerned.
> > >
> > > I also wondered why they called out a truncated pyramid
> > > shape for a foundation in soil. It is very hard to shape
> > > without forming and does very little to increase the
> > > capacity for the extra effort. (my opinion only)
> > >
> > > 73
> > > Hank Lonberg, S.E.,P.E.
> > > KR7X
> > > > In preparing for the installation of my Rohn HDBX-48 tower I
> > noticed that
> > > > the concrete base diagram showed what I refer to as a 'toe'.
> > That is, the
> > > > hole for the base is rectangular -- something like 5' x 5'
> > x5'.  However,
> > > > the bottom 12" flared outward creating an "L-shape" when viewed
> > > > cross-sectionally --  similar to   _| |_  .  Being quick to draw
> > > > conclusions, I figured the 'toe section' called for in the
> > diagram provided
> > > > additional leverage or strength.  I compared this effect to
> > that of toggle
> > > > bolts (AKA 'hollow wall anchors').  Once pushed through the
> > small hole, the
> > > > 'wings' spread out and provide strength against tipping or leaning.
> > > >
> > > > Now that plans have changed to use two AN Wireless towers
> > I've been asking
> > > > lots of questions about installation.  I have been told that you can
> > > > eliminate this "L-shaped" area by simply making the hole
> > rectangular.  (The
> > > > dimensions, of course, would have to be increased in order to make
the
> > > > vertical sides match what would have been the very outside edge of
the
> > > > 'toe'.)  The reason for the 'toe section', I was told, is NOT
> > mechanical
> > > > advantage or anything like that.  It was to save on concrete
> > costs.  Less
> > > > concrete means less cost.
> > > >
> > > > My question:  Is this 'L-shape' essential to tower strength?
> > If I increase
> > > > the horizontal dimension of the hole (to span the distance
> > from left toe
> > > > edge to right toe edge), do I weaken the structure?  Of
> > course, this change
> > > > WILL increase the mass of the concrete used in the base.  It would
be
> > > > easier, though, to dig the hole if all I need is a simple
rectangular
> > > > volume.
> > > >
> > > > gary b
> > > > k3gb
> > > > RVN BTO
> > > >
> > > > _______________________________________________
> > > > Towertalk mailing list
> > > > Towertalk@contesting.com
> > > > http://lists.contesting.com/mailman/listinfo/towertalk
> > > _______________________________________________
> > > Towertalk mailing list
> > > Towertalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> >
> >
> > #################################################################
> > #################################################################
> > #################################################################
> > #####
> > #####
> > #####
> > #################################################################
> > #################################################################
> > #################################################################
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>