Zigzag twisting line?

W

Winchman

Carpal tunnel level member
Location
Southwest Georgia
On my last two climbs I've noticed that the rope below me is all twisted into knots as I get near the ground. I had to pull it up off the ground to let it spin out the twist before it went through the Zigzag. The climbs were around seventy feet, the rope is Voyager, and I haven't changed anything recently. I've made close to a hundred similar climbs on this rope with no problem. What's going on, and why suddenly now?
 
How do you store the tail of your rope during your climbs? If the tail is always in the bag and not straightened out, it could build up twist overtime. If that's the case, try pulling all the rope out to release the twist
 
Jehinten said:
try pulling all the rope out to release the twist
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I do this occasionally on my main climb line (200ft), I usually hook the spliced eye to a tree with my lanyard as an anchor, then run the line thru a rescue 8 hooked to my harness, and walk it out to get it tight, and walk off the end so it snaps back, letting it fly helps get twist out (From my experience ymmv), works good, pain to put it all back in the bag (My bag flops shut, so I roll the top down, might get a 5 gallon bucket to store my rope)
 
treesap said:
I do this occasionally on my main climb line (200ft), I usually hook the spliced eye to a tree with my lanyard as an anchor, then run the line thru a rescue 8 hooked to my harness, and walk it out to get it tight, and walk off the end so it snaps back, letting it fly helps get twist out (From my experience ymmv), works good, pain to put it all back in the bag (My bag flops shut, so I roll the top down, might get a 5 gallon bucket to store my rope)
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For what its worth, just getting the rope out and laid out straight should do it. This happens often with rigging ropes after running through a porta wrap. Every couple of rigs just run the end of the rope out so that it doesn't build up coils. The other option (on rigging lines) is to wrap it the opposite direction every other time
 
treesap said:
I do this occasionally on my main climb line (200ft), I usually hook the spliced eye to a tree with my lanyard as an anchor, then run the line thru a rescue 8 hooked to my harness, and walk it out to get it tight, and walk off the end so it snaps back, letting it fly helps get twist out (From my experience ymmv), works good, pain to put it all back in the bag (My bag flops shut, so I roll the top down, might get a 5 gallon bucket to store my rope)
Click to expand...
Figure 8s can impart some twist in my experience.
 
I'm using a Ddrt system with a pulley at the top. The anchor rope holds up the pulley, so there's no way it can twist the climbing rope. I always make sure the two legs of the climbing rope are not twisted around each other before climbing. I don't see how the Zigzag or the pulley could induce much twist, so I guess it's just built up over time as suggested.

I keep the tail of the rope in a bucket near the tree. The rope is 175' long, so there was 30-40' feet in the bucket for the last two climbs. After the last climb, I pulled it out straight and held it loosely as I walked along it several times.

If the twisting persists, I'll remove the Zigzag, and let both ends hang from the pulley at my highest yard tree TIP. I can put a weight on them one at a time to see what that does. I can swap the rope end-for-end on the Zigzag at the same time, too.

Thanks for the suggestions.
 
I decided to go ahead and hang the rope from the pulley as described above. I didn't see any untwisting at all with the rope hanging free from a 78' TIP. My thirty pound lathe chuck spun half a turn, went back a quarter turn, and stopped on each leg.

I swapped ends on the Zigzag, climbed to the TIP, and came back down. I had put a weight on the tail of the rope so it couldn't untwist during the climb. There were two turns of twist in the rope between the Zigzag and the weight when I got down. That's not much, but certainly enough to add up over time.

I can't imagine how the Zigzag can put twist in the rope. It looks just fine, and it works flawlessly, just like it always has. The connection between the anchor rope and the pulley lets the pulley hang in line with the rope. The only other things that touch the rope are my hand ascender and gloved hands.

I'll just have to pay attention to the twisting. Fortunately it's easy to keep it from building up or to fix it when it does.
 
Winchman said:
I decided to go ahead and hang the rope from the pulley as described above. I didn't see any untwisting at all with the rope hanging free from a 78' TIP. My thirty pound lathe chuck spun half a turn, went back a quarter turn, and stopped on each leg.

I swapped ends on the Zigzag, climbed to the TIP, and came back down. I had put a weight on the tail of the rope so it couldn't untwist during the climb. There were two turns of twist in the rope between the Zigzag and the weight when I got down. That's not much, but certainly enough to add up over time.

I can't imagine how the Zigzag can put twist in the rope. It looks just fine, and it works flawlessly, just like it always has. The connection between the anchor rope and the pulley lets the pulley hang in line with the rope. The only other things that touch the rope are my hand ascender and gloved hands.

I'll just have to pay attention to the twisting. Fortunately it's easy to keep it from building up or to fix it when it does.
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I think rope just naturally has some twist, not necessarily from the Zigzag. Nothing to be concerned about, just pull the length of it out of the bag from time to time.
 
This could be a fun, long, geeky talk on rope construction, elongation, and memory. Just had this conversation with a friend two weeks ago. It’s so much fun to nerd out on this stuff. Alas, my evening is otherwise committed.
 
Winchman said:
I decided to go ahead and hang the rope from the pulley as described above. I didn't see any untwisting at all with the rope hanging free from a 78' TIP. My thirty pound lathe chuck spun half a turn, went back a quarter turn, and stopped on each leg.

I swapped ends on the Zigzag, climbed to the TIP, and came back down. I had put a weight on the tail of the rope so it couldn't untwist during the climb. There were two turns of twist in the rope between the Zigzag and the weight when I got down. That's not much, but certainly enough to add up over time.

I can't imagine how the Zigzag can put twist in the rope. It looks just fine, and it works flawlessly, just like it always has. The connection between the anchor rope and the pulley lets the pulley hang in line with the rope. The only other things that touch the rope are my hand ascender and gloved hands.

I'll just have to pay attention to the twisting. Fortunately it's easy to keep it from building up or to fix it when it does.
Click to expand...
Your rope probably has some built in twist, as the core strands are usually twisted to some extent - the twisting of the core determines the elasticity of the rope, straighter core means more static rope. When you climb, you stretch the rope, which straightens it, it does not always twist back completely when you get off of it, so the twist slowly turns into a tangled rope.
 
Well crimsonking mentioned it... he goes goes the geek out.

When arborist climbing lines are constructed they start out as small individual strands that are twisted into fatter, one, that are again twisted into yet fatter ones....and so in.

The rate of twist (per inch/mm) is controlled as it the direction. A “s” twist goes to the right, a “z” twist to the left. (I am dyslexic so this may be backward, but does not matter for the current conversation.)

A rope is said to be balanced when 1/2 the strands (final construction) are “s” and the other1/2 are “z.”

So the most “unbalanced“ rope? You got it good ‘ol 3 strand!

Left to its own devices the rope will twist/ counter twist overtime. The differences in rope are rate of twist for the strands and material of the strands, generally speaking.

Twist can be imparted by use and storage. Things like f8’s actual force a “change in direction” so to speak and will cause twist. I think you don’t notice it right away due to friction and the fall of the line absorbing it. If the fall can twist freely when using an f8 it will.

Pullies don’t impart twist, but due to low friction may show the natural back/ forth raveling due to balanced rope structure.

things like coiling the anchor end for tossing to rope advance will put twist in as will general use and storage. My theory is that MRS systems tend to impart”twist” more than SRS systems becuase in the MRS system the rope changes direction.

After all that geeking out, in short, modern arborist climbing lines are sophisticated tools that require, care, proper use and, maintenance like any other. Part of that maintenance is the occasional raveling of the hockels of use.

my .02

Tony
 
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