[TowerTalk] Chain and cable safety

[Roger K8RI on Tower]

The thread on pulling ground rods started me to thinking.



I've worked around chains, cables, and ropes all my life.  Anyone who has
never seen a chain, cable, or rope under tension break would have a
difficult time imagining the damage they can do and the speed at which they
can do it.



Short chains, cables, and ropes (I'm just going to call them chains from now
on) are not nearly as much of a problem, but you still need to be careful
and they can lash out to their full length (between anchor points) at times
when they break or slip.  Longer chains are almost unbelievable when they
let go under tension and the damage they can do is staggering.



A couple years ago one of my wife's cousins was pulling a 4 wheel drive out
of a ditch when the log chain broke and not so neatly removed the top half
of his head.  This was a heavy chain, not a light weight.  I have a 16' log
chain that is a real chore to carry from the shop to the car.  When we were
pulling a guy anchor the anchor point let go and that chain stood right
straight up as if something were pulling it up.



Check the length of chain between the anchor points and make that the
absolute minimum distance you are willing to stand from either anchor point.
If you are using a full length 20 foot chain to pull a truck out of a ditch,
then that is your minimum distance.  The most dangerous places are within
about a half a chain length to the right or left of either anchor point, but
they some times throw parts from what ever they were hooked to, or even the
part to which they were hooked and they can throw those a *long* way.



It's easy to forget just how much stretch there is in a chain or cable.  Of
course at their working and breaking strength they don't have to stretch
very far physically to store tremendous energy.



Several times I've been very fortunate.

I don't remember what we were working on now as it was a long time ago, but
I heard a buzzing sound.  I turned around and I remember everyone looking at
me.  A chain had broken and a piece had flown right over my shoulder. I
never even saw it.



Then there was the time we were shooting metallic silhouette targets with
the 9mm and 45.  I think I'll skip that one. <:-))



Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com