What if the cable breaks on a Lewis Winch?

Posted by: Lewis Winch

Q...Can the aircraft cable supplied with a Lewis Winch break and snap back and hit the operator?



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A... We have never heard of this happening with a Lewis Winch, but wire rope can - in some conditions - fail (break) and in so doing release stored kinetic (elastic) energy. The key to how much kinetic energy gets stored in a tensioned wire-rope, is the length of line that is out. A short length will not have enough energy to do much at all, even if it parts at the hook, while a much longer length parting in such a manner might snap back with enough force to hurt a person. As the Lewis Winch comes with only 150 feet of 3/16 "cable and the maximum single line pull is 4000 pounds this length and weight is unlikely to snap back with any force.

We also offer a 250 foot cable as an option for the Lewis Winch. There could be more stored kinetic energy in this cable because of it's length and therefore more potential of a snap back.

The simple cure is that if one has a lot of single line out and expects a hard pull, to drape a jacket or towel over the winch line at around the mid point. This way if the line were to part at the winch then the line is going away from you anyway, and if it parts at the hook then the jacket or towel will absorb the energy (unless the cable is damaged, it's very unlikely that wire rope will part in the middle somewhere).



If you have say 150 - 200 feet of line out and you drape a jacket at mid point, then if you are still winching by the time you reach the jacket then simply pluck it off and carry on. The amount of line still to go won't have enough stored elastic energy to do anything, and besides if you are still winching you probably aren't pulling hard anymore.

-All of the above is based on a person pulling very hard on a single winch line.
 
There's little need to do that if you are properly equipped.
 
Just put a snatch block on that really hard pull, and take it easy on everything.
 
Please visit our website to watch instructional videos.
 
http://www.LewisWinch.com/
 
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