Hi Dan,
Very good point you've brought up - about the safety cable system for
towers.
The common standard for tower safety cable is 3/8" x 12 strand steel cable,
with matching hardware - this for commercial applications mainly - however
more amateur radio tower builders could certainly stand to implement this
type of system into towers for hams. More amateur dealers should also carry
and advertise items such as this.
A couple more sources for safety cable restraint lines and devices are:
DBI / SALA http://www.dbisala.com/
Stratos http://www.trylon.com/stratos.htm
73, Dan KK3AN
AN Wireless
----- Original Message -----
From: "Dan Levin" <djl@andlev.com>
To: <towertalk@contesting.com>
Sent: Tuesday, October 09, 2001 7:48 PM
Subject: [TowerTalk] Fall Protection Suggestion
>
> I've asked enough questions and received enough great
> advice on TT - I wanted to try to contribute
> something for a change :-)
>
> In my recent installation of a Trylon 72' tower, I
> decided to install a 'professional' fall protection
> system. I've been very happy with the results, and
> want to encourage others to think about taking a
> similar approach.
>
> Most towers that I have seen and/or climbed have no
> fall protection system installed. The climber uses a
> fall protection lanyard, either with a single clip or
> a forked lanyard with two clips. In either case, you
> either have to climb unprotected (efficient, but very
> dangerous), or clip and unclip every couple of steps
> up and down the tower. With a single lanyard, every
> unclip to move your protection is risky. With a
> double lanyard you don't have the risk, but you still
> have the hassle of moving your protection every
> couple of steps.
>
> In at least some (maybe all, I don't know)
> professional tower installations, a permanent fall
> protection system is put in place. These systems use
> a track or cable to provide 100% continuous fall
> protection to the climber.
>
> Summary:
> On my Trylon, I installed a steel cable that is
> securely attached at the top of the tower, and runs
> down one face. I used spacers at the top and bottom
> to keep the cable off the tower face. A "trailing
> rope grab", an OSHA approved device that clamps on to
> the cable in the event of a fall, clips on to my fall
> protection lanyard and follows me up and down the
> tower as I climb. I am protected all the time, and
> don't ever have to unclip my lanyard. This system
> allows me to climb quickly and securely, without
> danger and without the nuisance of managing my
> protection on my way up and down the tower.
>
> Details:
> I bought an 80' length of 5/16" galvanized steel
> cable from http://www.mcmaster.com for $.42/ft. The
> cable attaches around a leg and to my thrust bearing
> plate at the top of the tower using 3 cable clamps
> per the manufacturer's spec. It then runs through a
> 12" long 1" wide 1/8" thick piece of galvanized steel
> that serves solely to space the cable off the face of
> the tower. I bought the spacer steel at a local
> Orchard Supply Hardware store, and had a local
> machine shop bend at 90 degrees at one end (to hook
> over the brace of the tower) and drill a hole at one
> end for a 1/4" bolt (to hold it to the tower brace)
> and at the other end to allow the cable to pass
> through.
>
> The cable then runs down the face of the tower to a
> second identical spacer at the bottom of the tower.
> A single clamp below the lower spacer provides enough
> tension to keep the cable straight and spaced off the
> tower face.
>
> Imagine at this point a 5/16" cable running parallel
> to and about 12 inches from one face of the tower. I
> installed my tower intending to climb the north
> facing 'nose' (to keep the sun out of my eyes), so I
> installed the cable on the face that is to my left as
> I climb.
>
> Then I bought a Miller Microloc trailing rope grab
> from www.grainger.com. The rope grab is designed for
> use with 5/16" steel cable. The grab clips on to the
> fall arrest lanyard. It runs along the cable, and at
> least in the upward direction it just slides along
> the cable behind me as I climb. Going downward it
> sometimes requires that I reach out and slide it down
> the cable, which is no hassle. I think if I had
> chosen a more expensive grab, it would trail going
> down more easily.
>
> The summary is that for around $200 ($116 for the
> Microloc, $35 for the cable, a few bucks for the
> clamps, spacers, etc.), I have a full time reliable
> fall protection system. In the context of a multi-
> thousand dollar tower system, $200 seems well worth
> it. You might consider adding such a system to your
> tower(s) if you climb them much. It sure makes me
> feel safer than climbing towers without them.
>
> All the best, and safe climbing,
>
> ***dan, K6IF
>
> List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
> Trylon Titan towers, coax, hardline and more. Also check out our self
> supporting towers up to 100 feet for under $1500!!
http://www.anwireless.com
>
> -----
> FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
>
>
List Sponsored by AN Wireless: AN Wireless handles Rohn tower systems,
Trylon Titan towers, coax, hardline and more. Also check out our self
supporting towers up to 100 feet for under $1500!! http://www.anwireless.com
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|