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Re: [TowerTalk] 45G Fdn

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] 45G Fdn
From: "W7CE" <w7ce@curtiss.net>
Date: Thu, 6 Sep 2007 20:50:17 -0700
List-post: <mailto:towertalk@contesting.com>

> 1. Do I really use rebar for my CB2 hole?
>
> Yes, really.  You need Qty=4, No. 4 bars vertical and None horizontal (but 
> won't hurt to install them to hold the verticals in place during the 
> pour).
>
> If so, what are the lateral ties shown?
>
> None needed for a CB2
>
> Are they rebar or wire?
>
> Since none are specified you could use wire to hold the verticals in 
> place.
>
> I presume they hold the four vertical rebar pieces rigid?
>
> In the larger bases they add structural support as well.
>

I think if you look at the drawing and notes more carefully you'll see that 
not only is the vertical rebar necessary, but so is the horizontal.  The 
drawing I have (C610621) calls for 4 No. 6 vertical rebar with horizontal 
rebar spaced every 12" in a CB1 base.  The chart shows no horizontal rebar, 
but if you read the associated note it specifically says "Horiz. bars in 
chart refer only to the bars in the foundation pad."  Since a CB1 has no 
foundation pad, it makes sense that the chart would list none.  But for the 
body of the foundations the drawing specifically calls for "No. 3 lateral 
ties at 12" max. O.C. req'd on all piers (see tie-bar details)."  If you 
look at the tie-bar detail drawing, the horizontal ties are shown as one 
piece loop construction with the ends folded around a horizontal rebar to 
lock them in place.

It should also be noted that the Rohn catalog calls for a pier pin base on 
all guyed towers.  Embedding a section of tower in concrete is only 
specified for bracketed or free-standing towers.  I realized that 
long-standing ham tradition has been to ignore the Rohn catalog designs, but 
personally I would stick with their recommendations.

73,
Clay  W7CE




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