What Causes A Cable to Do This?

[Stitchit1]

What Causes A Cable to Do This? (Pictures Added)

Hi guys,

I'm wondering if you can tell me why this cable is doing this? It's 3/8" 140' long. I had lost the pin from one of my cinch blocks. I couldn't get another one, so instead I used one of these, due to the fact the color was better so I could see it if dropped in the snow again.

Here's a picture of that pin:

Unfortunately, soon after making up that cable, I managed to have the cable get wrapped around the long pin, causing a light curling edfect part of the cable. About 12'.

I've been removing trees along a power line, using the same cable to put tension on the tree so it falls the correct direction away from the power line.

The cable has been showing a lot more pronounced curling as well as many more curls in it. It now looks like this:

Do you feel the additional curls are caused from the hurt I did originally by putting the cable over the pin? Or am I putting too much force on the cable while pulling?

Most important, does the curling effect the cable as far as it still being safe to use?

Thank You,

Chris

 

[PHPaul]

Re: What Causes A Cable to Do This? (Pictures Added)

You'll probably get a better technical explanation, but my (limited) experience is that the curling of the cable is primarily due to the way the individual wires are laid (twisted) together when the cable is made up.

A hard pull will stretch it a bit, tightening the lay and giving the curl effect.

As long as there are no sharp kinks or nicked wires, you haven't (as far as I know) affected the strength of the cable.

 

[skeets]

I would say this may have been caused by several actions, one improper unrolling of the wire rope or a shock load both will deformation the cable and cause damage.
This is one of the sites I used when teaching hoist and elevators when I worked for the Govt,, it is not the total all to end all but a pretty good over view

http://www.globalsecurity.org/military/library/policy/navy/nrtc/14251_ch5.pdf

 

[85Hokie]

I would say this may have been caused by several actions, one improper unrolling of the wire rope or a shock load both will deformation the cable and cause damage.
This is one of the sites I used when teaching hoist and elevators when I worked for the Govt,, it is not the total all to end all but a pretty good over view

http://www.globalsecurity.org/military/library/policy/navy/nrtc/14251_ch5.pdf

Skeets,

thats good stuff!!! I learned something!

 

[Stitchit1]

Thanks Skeets! I'll check that site out.

 

[bcp]

From:
saiaonline.org

Make sure that guides and sheaves turn freely as the wire rope moves. A moving rope over a nonmoving object will create a permanent pigtail (curl or corkscrew).
====================

Same process as this:

https://www.youtube.com/watch?v=rX3DriXM0NM

====================

 

[Stitchit1]

Strange part is it had only a slight wave in the cable when I hooked the pin with it. It remained the exact same until I started pulling these trees & putting strain on cable

 

[bcp]

If you unrolled it with the "incorrect" method shown below, the pull may have reinforced the coiling.

Bruce

 

[North Idaho Wolfman]

Sadly corkscrewing or Pig tailing happens when the wire is damaged by being bent too tight around guides and sheaves or in this case a pin.

It's a goner, there is no way to fix it.
The outer strands have been stretched and it's only a matter of time before they fail completely and break.

I've done the same to cables several times.

 

[Stitchit1]

Thanks guys! When I bought the cable from tractor supply, I helped the employee roll it off the spool. Small spool, not near as big as spool shown. From there, just hand coiled onto the floor. Picked up the cool, & used it.

 

[Tooljunkie]

If it constantly rolls tight against a fairlead, this will happen too. New cable should be rolled out straight and laid onto winch under tension. If just using it without winch, just for yarding trees with a tractor, then its likely a shock load that did it. Sometimes stretching it out and leaving it will straighten it somewhat. Tied to an immoveable object and tensioned with a moveable object and left overnight will straighten it. Not always.

 

[Diydave]

Thanks guys! When I bought the cable from tractor supply, I helped the employee roll it off the spool. Small spool, not near as big as spool shown. From there, just hand coiled onto the floor. Picked up the cool, & used it.

Bingo, we have the answer, TSC cable = cheap chinese crap. At least HF doesn't charge 3X the money as TSC does. Now you know what TSC stands for, don'tcha?

 

[Stitchit1]

Hf? Harbor freight?

 

[Stitchit1]

Diydave,

Isn't this hilarious,.... Called hf,.... After about three minutes of trying to explain what it was I'm asking for, the nice lady with a very pronounced foreign accent said, "Oh, me so sorry, we not carry".