From: david gudmunsen (kroctec@btopenworld.com)
Date: Mon Aug 08 2005 - 14:28:38 PDT
Hi Kenny,
I am always very concerned when the subject of cables comes up. My father
was aboard a ship where a cable parted and one of the crew killed and
another very seriously injured. Every year there are horrendous so called
accidents involving winching/lifting operations that have gone badly wrong.
I also have personal experience of seeing cables part and fixings fail. The
kinetic energy release is huge and very scarey.
Firstly cable strength is determined by not only the combined cross
sectional area of the wires in the cable but also by the tensile strength of
the material (hugely variable and not ascertainable without testing). There
are also many factors that can seriously reduce the safe operating load of
any rig and don't forget that the whole is only as strong as the weakest
part.
Remember that there is a legal duty of care with regard to the safety of
other persons and you need to cover your ass.
This said any cables should have a current inspection safety certificate. A
further point is that shear pins are placed to ensure that overload does not
occur so these should be to a precise specification having also a
certification and it is wise to colour code them so that there can be no
chance of fitting the incorrect shear pin.
Depending on how you rig the operation a 10000 lbs winch has the capacity to
tear either vehicle to pieces.
My final advice is to go, with your cables, to a crane winch cable supplier
and get them to do appropriate tests and issue you with a certificate and
also correct shear pins. Cables should also be periodically retested
(annually) or if you see any signs of damage when the cable should be
regraded and possibly broken down so the damage is no longer in the system.
Best regards from David Gudmunsen
Feel free if you want to get back to me on any points.
on 8/8/05 13:43, Recovry4x4@aol.com at Recovry4x4@aol.com wrote:
> Gang, just how strong is 1/2" winch cable? Reason I'm asking is my M756A2
> has the conventional 10,000# capacity deuce winch on the front that carries
> 200' of 1/2" cable. (Had to add the word capacity becuase some moron would
> tell
> me my front tires are overloaded). The truck also has a 20,000# capacity
> winch on the back. It's nearly identical to the winches mounted on the front
> of
> 5 tons. The manual calls for 300' of 1/2" cable for this winch also. Should I
> be concerned about putting the same size cable on both winches considering
> the fact that this one is rated a twice the capacity? I do plan on working
> the
> winch too!
> Just a thought and question!
> Kenny
>
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This archive was generated by hypermail 2.1.4 : Fri Oct 28 2005 - 23:25:27 PDT