Rope Length ??!!??

[shibumi]

I am about to start stuffing my ropes since I cannot seem to learn the magical secret of how to make it perfectly roll out when you toss of over the side. It winds up being a twisted snake nest and then I cuss for 10 minutes trying to sort it out.

Ahhh. One shouldn't throw a rope down a pit. While it looks good for the camera, it's not good form for several reasons:

In throwing a rope, one can more easily dislodge rocks and debris.

For longer pits it can potentially damage the rope, especially if the rope "whips" (the end of a whip can easily go
supersonic...), creating all sorts of difficult to measure shock loads on the rope.

There's the potential for knotting or rope getting hung up on ledges.


Coiling a rope properly is pretty easy with a little practice, and paying a rope out when undone properly isn't
difficult either.

[graveleye]

yea I've learned as much. I'm still new to the game and the deepest drop I've ever rigged was 45' anyway. I've figured out not to throw it, but had to learn the hard way

[Patrick Wilson]

How about letting the stuffed rope bag hang under you while on rope, only the rigged part out of the bag so far, letting it come up behind you as you rappel....anyone do that?

[Carl Amundson]

Bill
Wow, impressive rope list! I have a couple new, unused 600+ PMI's that I've been saving for a pilgrimage to Ellisons. Next year I turn 50, so it's my goal to do a crossover trip to celebrate.
DR J

Jay, Let me know when you plan to go.
I would love to join you.

Carl

[Scott McCrea]

Me, too.

[Chads93GT]

Guys and Gals,

I am looking to buy a new rope after Christmas and I wanted a little input. I did a 130' pit last weekend, twice, on a friends Talon rope and it was pretty darn cool. I liked it better than my EZ bend, and I like it better than ny friends PMI classic pit ropes. I noticed a few weeks ago while climbing up a 122' cliff in southern illinos that the pit ropo streached quite a bit while getting on rope, and it bounced a lot while climbing. The Talon, not so much. Basically I want to get the PMI Talon rope, but I want to get enough to compensate for shrinkage, and being able to rig any of the surface pits at TAG. Also it would be nice to have enough to do a pull down on the big cliffs in southern Illinois. I was thinking somewhere between 350 and 400 feet, but my real question is how much does the Talon shrink? My EZ bend shrank 13 feet, as it was a 150' rope. I know the classic pit rope shrinks 8-10% as well. I just haven't been able to find how much the Talon shrinks on here. I see the question was asked, but only sarcastic answers were given.

Thanks.
Chad McCain

[ek]

PMI EZ-Bend and PMI Max-Wear (PMI Pit Rope is really just 11mm PMI Max-Wear without the sheath pattern) are nylon ropes, and nylon shrinks with age. PMI Talon rope, however, has a polyester core, covered by a nylon sheath. The polyester core is why it is so much less stretch. It's also why it has such a slimmer margin for error--don't take significant falls onto it, or bad things will happen. Never use it with an inexperienced rigger, and be reluctant to use it with inexperienced cavers.

Polyester doesn't chemically absorb water like nylon does, and does not shrink over time. The sheath could potentially shrink, but I've never heard anyone indicate this as a large problem. I do know that people sometimes have to cut off excess core that has protruded out of the sheath on Talon rope, but I don't think it ever amounts to a substantial fraction of the rope.

People I know who use Talon extensively have told me that they have never noticed any shrinkage whatsoever, over many years of use.

[Chads93GT]

duly noted about inexperienced rappellers on the rope and riggers of the rope. Ive read a lot about your posts on the fall factor to know what you are talking about, or anchors failing and shocking the rope, etc. You definately answered my questions and the rope shrinking. Thanks.

[Amazingracer]

I own 3 talon ropes of varying lengths (100,200,300), and upon washing in a front loading washing machine a time or two and several wet multi drop trips i only lost about 1-2% of rope due to shrinkage on all the ropes. And given that sometimes PMI gives you a little extra rope in the spool/coil, my ropes have still stayed above or at their 100,200 and 300' lengths.

As EK pointed out the poly doesnt stretch for falls, but if you are taking significant falls on your caving rope, then you have bigger fish to fry. But thats a different story.

So far after one year of intense use I love my Talon ropes. I have the 11mm because I was worried about edge wear on the rope, otherwise I would have definitely sprung for the 10mm.

[ek]

As EK pointed out the poly doesnt stretch for falls, but if you are taking significant falls on your caving rope, then you have bigger fish to fry. But thats a different story.

If you're taking significant falls onto your caving rope, and your caving rope is not stretchy enough to absorb them, then that is probably your biggest fish to fry!

If you rig a short traverse line from one bolt (or a tree) to a pitch-head bolt, and while someone's on the rope the pitch-head bolt fails, they will take a significant fall onto the rope. With a nylon rope they'd probably be fine. With a polyester rope, not quite as likely. A polyester rope does have some shock-absorbing ability, but nothing near the shock-absorbing ability of nylon rope.

Besides failures of a primary anchors dropping you down onto a backup, you can have failure of one anchor in a wide Y-belay, failure of one anchor in a slacky traverse line, rebelay failures, failures of high-angle redirects, the rope being inadvertently snagged on a horn which then breaks loose, falling on the rope that you're clipped to for safety while rigging a traverse line, and exhausted/hypothermic/hypoglycemic/novice cavers advancing upward with the aid of rock features without advancing their ascenders and then falling.

I am not representing that as an exhaustive list. A couple other plausible (though colorfully described) scenarios are presented by wyandottecaver in this post.

Anyone who rigs with a polyester rope should be aware of things like that, should when and how they can be avoided, and should be able to judge whether or not a polyester rope is safe given the situation. If it's not, you can (sometimes) change the situation...or change the rope.

TAG cavers who use Talon have told me that they have found that the Talon works for most or all the situations they rig...but that it does affect their decisionmaking about how to rig.

Polyester ropes do have significant stretch--just not nearly as much as nylon. But a stretchless rope's suitability to caving would be much less than that of a polyester rope's.

[Chads93GT]

If there are no rebelays, and it is a simple case of rigging a tensionless hitch around a tree for a pit drop, then it will be fine...................

I can see how it would cause issues for in cave pit drops from multiple rig points.

[ek]

If there are no rebelays, and it is a simple case of rigging a tensionless hitch around a tree for a pit drop, then it will be fine...................

Then it's definitely OK to rig with a polyester rope, yes...provided that the people USING the rope are sufficiently experienced not to allow slack to accumulate above them. What's simple for you may not be simple for someone who is inexperienced.

I recall a trip where someone who'd had a good deal of training had a bit of difficulty climbing up a 60' drop, because it was awkward at the top--tight, with some stuff jutting out. Nothing on the surface can perfectly capture what it's like to do SRT in a cave. So he free-climbed about fifteen feet. Which is fine. Except that he didn't advance his ascenders while doing so. I had told everyone on the trip, before we went into the cave, that they needed to always advance their ascenders and make sure no slack accumulated above them. But when you're first starting vertical caving, there's a lot to remember, and some people will forget things.

When I saw him near the lip, and I saw that he had not advanced his ascenders, I yelled for him to do so and he did. At that point there was about 8 feet of rope (not including slack) between him and the tree where the rope was rigged with a tensionless hitch.

If he'd fallen before pulling the slack through, then going by the amount of slack accumulated divided by the total rope between him and the anchor, he would have taken a 15-foot long fall of about factor .6. He might have scraped along the wall some, reducing the fall energy...but not reducing it to something small. The rope had a nylon core, so if this had happened then his Croll would likely have cut the sheath of the rope and pulled it down, exposing the core and scaring the living daylights out of him. But it would probably not have cut the rope.

On the other hand, if the rope had a polyester core, his Croll would probably have cut the rope in two and he would have fallen 60' to the ground.

In another simple rigging scenario that wyandottecaver brought up (see the link in my previous post), where you have a rope rigged to a single, bomber feature in a cave near the ground and run it along the floor for a significant distance before the drop, you have another plausible mechanism for a shockload. Caver A climbs up the drop and slack accumulates above. Caver B is standing at the top and steps on the rope, pinning the slack between his foot and the anchor. The friction along the floor prevents the slack from being pulled out, even when the rope is weighted by Caver C. Feeling the tension on the rope from Caver C, Caver B looks down, thinks "my bad," and steps off the rope. Then the slack quickly comes out of the rope, resulting in caver B taking a fall.

I can see how it would cause issues for in cave pit drops from multiple rig points.

Sometimes. But just as people not being careful can result in shockloads with a single anchor point, you can rig carefully and thoughtfully with multiple anchor points and avoid shockloads of sufficient magnitude to be problematic with a polyester rope.

A polyester rope does have some stretch. You can generally rig a Y-hang off two anchors with a polyester rope...so long as you make sure that the extension will be minimal if one fails (so don't rig with the dynamic load-distributing system presented in On Rope and in the NCRC level-3 curriculum--rig a static load-sharing anchor instead, like you'd probably do anyway). Rigging from two bolts on the same wall is even easier--you can do it the same way. You can even sometimes use polyester rope to rig a traverse line with a single (i.e. non-redundant) pitch-head anchor...so long as the distance between the pitch-head anchor and the closest traverse anchor is sufficiently small. I've been told that you can even sometimes rig a rebelay, so long as there is a whole lot of rope out (i.e. the rebelay is much lower than the top anchor or next highest rebelay...I'm not sure how much lower it has to be though), and it is rigged with no more slack than necessary to progress on the rope above and step into the rebelay loop.

[Chads93GT]

I definately teach people not to ever stand on the ropes. Not for THAT reason, but that is yet another reason why to be very aware of the rope on the surface. Afterall, someone not paying attention could also trip over the rope, take a fall and tumble out of control, over the ledge and fall to their death.

[ek]

One other thing I forgot to reiterate is that you can have a simple drop, rigged off a bomber tree at the top with a tensionless hitch (or any other accepted way)...and if the rope inadvertently gets hooked around a projection, which breaks away while someone is on the rope, then this will cause a shockload as well.

Polyester ropes should be used only by riggers who understand all these issues, and by cavers (i.e. SRT practitioners) who are capable of recognizing when something is just not right...and performing the necessary maneuvers to get out of bad situations (e.g. changeovers).

I definately teach people not to ever stand on the ropes. Not for THAT reason, but that is yet another reason why to be very aware of the rope on the surface.

Or at the top of an in-cave drop. On the surface, there are usually good trees nearby to rig off. In the cave, when rigging with natural anchors, it is often necessary to go back from the drop farther, and that's when there a long length of rope to step on (or avoid stepping on). Furthermore, in order to hold slack at the top of a loaded rope by standing on it, you have to have a significant length along the ground to get enough friction.[1]

It is important to train people not to get tangled up in the rigging, including the pit rope. Stepping on and tripping over a rope that is in use, or rigged for use, are bad things because they can result in the person tripping or slipping, and falling. However, the traditional wisdom that stepping on ropes physically degrades the ropes has been largely discredited, and the idea that one ought not step on a rope when at the bottom of a drop, or when it is not rigged, seems to be entirely a matter of etiquette. This is not to say that etiquette should be abandoned--but it should be subordinated to actual safety concerns (including efficiency, which is part of safety), and as a culture (or sub-culture, as it is) we should work to change the acceptance of counterproductive rules of etiquette.

Accidentally tripping and falling because you're trying to make sure not to step on a rope is just as bad as stepping on and tripping over the rope or rigging.

[1]EDIT: Fixed this sentence.