[Top] [All Lists]

Re: [TowerTalk] Climbing and working on Rohn 25g/45g towers -

To: "Bill Aycock" <>
Subject: Re: [TowerTalk] Climbing and working on Rohn 25g/45g towers -
From: "Alfred Frugoli" <>
Date: Mon, 24 Nov 2008 15:11:01 -0500
List-post: <">>
What is difficult in this entire conversation for me is that I'm not an
engineer - I'm trained as a manager and I'm an amateur radio operator by
choice.  You can talk about specs and theory all you want.  What I need to
know is where do I connect my fall arrest lanyard.  It seems to me that no
matter where you connect to on xxG tower you're connecting to a cross
brace.  If I connect directly on the cross brace, obviously I'm on the cross
brace.  If I connect on the tubular vertical member and I fall, the force
still rests on the z bracing where it is welded to the vertical tube.

So, how does one safely connect their fall arrest lanyard on xxG tower?
Must it be connected to multiple legs to be safe?

A pictoral tutorial of this information would be helpful.  My knot book with
diagrams, pictures and drawings is invaluable to me - is there such a thing
for tower rigging and climbing?

73 de Al, KE1FO

Visit my amateur radio contesting blog at

On Mon, Nov 24, 2008 at 2:55 PM, Bill Aycock <> wrote:

> Richard-
> I  still consider that your post contains statements that are essentially
> meaningless, because they relate to loads in terms  that do not directly
> relate without more explanation and definition.
> My career was as a Rocket motor designer, and , of necessity, included a
> working knowledge of material properties and how they relate to applied
> loads. My problem with your statements is that there is no meaning to the
> phrase "shear strength" without knowing how the loads are applied. The
> primary loads on a guyed tower are compressive and tensile; on an unguyed
> tower, bending becomes more important. In a tower, the applied loads are
> compression and tension, with shear being induced, not directly applied.
> The
> resistance to shear in a complex structure is different for different parts
> of the structure, and can not be determined if the point of force is not
> given, with respect to the geometry.
> When a climber hangs on a tower, the total load is his weight, but the
> stresses are distributed differently if he is in line with a 'point' or a
> 'face'; to determine factor of safety, one must know where he is. This is a
> fact.
> At one point in your answer you claim that  you have just stated the facts.
> To be a useful fact, the statements you made need more clarification.
>  Where
> did the shear strength statement come from, and did it originally
> come with a definition?
> Bill-W4BSG
> ----- Original Message -----
> From: "Richard Elizondo" <>
> To: "Bill Aycock" <>; <>
> Sent: Monday, November 24, 2008 11:24 AM
> Subject: Re: [TowerTalk] Climbing and working on Rohn 25g/45g towers -
> > The strength of the section is made up of its parts. If the section fails
> > to
> > provide a 5000lbs anchor point, in no way will any of the welds, legs or
> > lattice, provide it either.
> >
> > I am not stating the 25g tower is worthless. I actually quite fond of
> this
> > tower and own several gin poles that are made of 25g, 45g and 55g
> > sections.
> >
> > What I have stated are just the facts. Like it or not, take it to heart,
> > or
> > with a grain of salt.
> >
> > Ever wondered why Rohn used to make comments about climbers being less
> > than
> > 250lbs in their field erection manuals ? (Hmmmm ...250lbs ...10-1 safety
> > factor for positioning.... I must not know what I am talking about.)
> >
> > Seriously though however, I am open to discussion on what you see as
> > erroneous in my post, since it is the same lecture given in all comtrain,
> > belltech, and Radian fall protection classes.
> >
> > Richard
> >
> > ----- Original Message -----
> > From: "Bill Aycock" <>
> > To: "Richard Elizondo" <>;
> > <>
> > Sent: Monday, November 24, 2008 8:31 AM
> > Subject: Re: [TowerTalk] Climbing and working on Rohn 25g/45g towers -
> >
> >
> >> This Whole post contains a major flaw that makes the real part
> >> irrelevant.
> >> The statement about the strength of 25g is worthless, because the shear
> >> strength is not define with respect to direction and method of loading,
> >> and
> >> is not related to the type of load applied by a falling body.
> >> If the loading is cleared up, the rest might be germane.
> >> Bill-W4BSG
> >>
> >>
> _______________________________________________
> _______________________________________________
> TowerTalk mailing list

TowerTalk mailing list

<Prev in Thread] Current Thread [Next in Thread>