[TowerTalk] Climbing belts/harnesses demonstration

[Dave NØRQ]

I saw most of that demo as well.  It was a good thing to have
at Hamcom!  (And Hamcom was very good this year.)

During #3 below (a 6' lanyard with a knot), I managed to take
a picture, right after he released the weight, as it was falling,
before the lanyard attempted to stop the weight.  You can see
the pic at www.qsl.net/n0rq/images/badknot.jpg  -- and as Mike
mentioned, the lanyard snapped like it was a string -- yes,
right where the knot had been.

The lesson was painfully clear.

- Dave N0RQ



----- Original Message ----- 
From: "Mike Bragassa" <bragassa at consolidated.net>
To: <towertalk at contesting.com>
Sent: Wednesday, June 14, 2006 09:35
Subject: [TowerTalk] Climbing belts/harnesses demonstration


> This past weekend at HamCom in Plano Texas; a representative of Pinkerton
> Sales; a manufacturing rep company for "Ultra-Safe", a climbing belt
> ("fall-arrest")  company, gave an excellent demo outside of the convention
> hall on their demo-trailer. He would winch up a 220# weight and demo
> different situations. The message was that different lanyards (  position 
> or
> fall-arrest, whichever) exert dramatic differences in force to the user 
> when
> a fall occurs.
> As I recall (+/-)and briefly:
> 1. Six foot conventional lanyard: 2500# (ouch!)
> 2. Six foot lanyard w/ sewn fold-out layers (shock absorbing): 700# (still
> "ouch")
> 3. Six foot lanyard, now get this,  WITH A KNOT IN IT: "0" force; it broke
> instantly! (Big ouch!)
> At least on two of the ouch's, the user survived.
...