Re: [TowerTalk] How to Clip on with a Fall Arrest Lanyard

[Grant Saviers <grants2@pacbell.net>]

I think you are correct, clipped on either way the weld is the ultimate 
structural stop.  If one weld gets broken then the next one (Z bracing) 
is certainly going to hold.  Note there is one Z per horizontal section 
that stops at its end, so if clipped to it, there is no second welded 
diagonal.
The OSHA spec for fall arrest is to limit the max G load to 1800 lbs. 
5/16" diameter R25 bracing has a yield tension around 3500#, probably 
not enough of a safety factor for all the ways the load might be 
applied, condition, etc.
The ultimate redundancy and unambiguous connection is around a leg.

Grant KZ1W


On 9/6/2020 19:28, Ken K6MR wrote:
> Thinking out loud here, and as an EE not an ME.
>
> If you clip onto a vertical leg, when the fall arrest deploys, the only thing stopping the 
> Gorilla hook from sliding down the vertical member is the cross brace where it is welded to 
> the upright.  Common sense says that it will wedge itself into the ‘V’ created 
> between the cross brace and the tower leg.
>
> If you clip onto a cross brace, the Gorilla hook will slide down the cross brace and stop at 
> the weld between the tower leg and the cross brace.  Again, it will be wedged into the 
> ‘V’ between the two.  There will be virtually no leverage on the cross brace, 
> so the chances of the cross brace bending away from the tower would seem to be almost nil.
>
> The only way I could see either method failing is if the weld pulled away from 
> the leg.  What am I missing?
>
> Ken K6MR
>
> From: Stephen Shobe<mailto:info@pioneerantenna.com>
> Sent: Sunday, September 6, 2020 19:14
> To: Kim Elmore<mailto:cw_de_n5op@sbcglobal.net>
> Cc: towertalk@contesting.com<mailto:towertalk@contesting.com>
> Subject: Re: [TowerTalk] How to Clip on with a Fall Arrest Lanyard
>
> My advice as a certified tower climber is to always use the legs of the
> tower with your fall arrest system. Cross members have weld points subject
> to failure if the load is significant. And remember, none of the connecting
> points are engineered fall arrest points
>
> On Sun, Sep 6, 2020 at 18:47 Kim Elmore <cw_de_n5op@sbcglobal.net> wrote:
>
> > Would you mind being a bit more detailed about this? What it is,
> >
> > exactly, and how you manage it? I think I know, but I want to be
> >
> > certain. Also, if there's a permanently-installed a safety line on a
> >
> > tower, what's required to properly use it?
> >
> >
> >
> > Kim N5OP
> >
> >
> >
> > On 9/6/2020 4:17 PM, K9MA wrote:
> >
> > > I’ve been using a 5/8 inch lifeline and a rope grab. It takes one trip
> > with the gorilla hooks to put it up, and another to take it down, but all
> > the other trips are much easier.
> >
> > >
> > > 73,
> > > Scott K9MA
> > >
> > > ----------
> > >
> > > Scott Ellington
> > >
> > >    --- via iPad
> > >
> > > > On Sep 6, 2020, at 12:05 PM, Dick Green WC1M <wc1m73@gmail.com> wrote:
> > > >
> > > > 4. All this further convinces me that a safety cable is the best way to
> > climb a tower. I plan to install one on my Rohn 55 tower provided I can
> > find one with enough clearance to pass through the three TIC rings on my
> > tower.
> >
> > > _______________________________________________
> > >
> > >
> > >
> > > _______________________________________________
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> > > TowerTalk@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/towertalk
> > --
> >
> >
> >
> > Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP
> >
> > SEL/MEL/Glider, N5OP, 2nd Class Radiotelegraph, GROL)
> >
> >
> >
> > /"A great second violinist plays second fiddle to no one." //– Robert C.
> >
> > Marsh, Chicago Sun-Times./
> >
> >
> >
> > _______________________________________________
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> >
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> >
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> >
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> >
> > --
> Stephen K. Shobe
> Pioneer Antenna & Tower
> 25182 Derby Cir
> Laguna Hills, Ca. 92653
> 949.235.9202
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