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Descending/ascending tubular nylon webbing?

Original Post
Don Ferris III · · Boulder, CO · Joined Nov 2012 · Points: 186

I know use a rope right? I don't have a good reason as to why. Just wondering. It may come in handy.

How would you rap with tubular nylon webbing? Munter? Thread it through your Atc like you would a rope?

What about ascending? Let's pretend it's double over with the intent to pull it but after consideration you have to go back up. Will prusiks work?

Thanks a bunch.

Aleks Zebastian · · Boulder, CO · Joined Jul 2014 · Points: 175

climbing friend,

you would be doing the dying

john greer · · modesto · Joined Jun 2009 · Points: 110

LOL ^^^

I think the question is valid for some emergency situations.
Munter might work. Prusiks seem like they would work with enough wraps. Not sure if I would want to test it in an emergency though.

And...

YUR GONNA DIE!!

Ryan L · · Ringwood NJ · Joined Sep 2014 · Points: 105

NO!

just nope

Webbing has edges unlike rope. Munter hitches would make the webbing cut right through itself and you would fall. If you ever drop your rope, and have enough webbing to reach the ground, get somebody to tie the rope to the end of the webbing and then pull it up. DON'T RAPPEL ON WEBBING!

and to whomever tells me the webbing won't cut through itself because the rope will be moving through the knot and the friction won't be localized to one spot, I dare you to try it and actually find our answer ;)

jacob m s · · Provo, Utah · Joined Apr 2011 · Points: 135

Me and a friend have done a bunch of 10' to 15' raps on 1" webbing while canyoneering, we feed it through an atc just like normal. It doesn't feed the best, but it works great when its just not a good place to use the webbing like a hand line, and breaking out our 200' rope would be a pain. I would not want to rap 100' on webbing though, it can cut into your hand a lot more then rope.

But i agree that for a climbing situation if you have enough to get to the ground, i would lower and ask somebody to tie a rope to it. But that might not always be possible.

As for going back up the webbing i would think a prussik would work, but i would very hesitant to try that. I do have the roll-n-lock by climbtech and it will work with 3/4" webbing as a rope clamp, so maybe you could find a rope clamp big enough to do use on 1" webbing.

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346
Ryan L wrote: Munter hitches would make the webbing cut right through itself and you would fall. If you ever drop your rope, and have enough webbing to reach the ground, get somebody to tie the rope to the end of the webbing and then pull it up. DON'T RAPPEL ON WEBBING! and to whomever tells me the webbing won't cut through itself because the rope will be moving through the knot and the friction won't be localized to one spot, I dare you to try it and actually find our answer ;)
... what?

Anyway, a long time ago, I rappelled on webbing a few times using a figure eight. It worked fine. It's probably better than rappelling down 6mm cord, which I have also done.

As far as ascending it, a prussik would probably work, although it's probably best to avoid ascending webbing unless an emergency.
Eddie F · · Edwards, CO · Joined Dec 2012 · Points: 25

If it is just descending then ascending, and you had enough webbing, couldn't you just tie a bunch of overhand knots in a few feet increments and down aid/aid the webbing?

johnnyrig · · Unknown Hometown · Joined Dec 2011 · Points: 105

Oh look, people have already rapped it. Guess that part of the question's answered. I would have thought a munter, or maybe a super munter would work pretty well. The super munter adds enough friction that rapping off a single strand of paracord (as an experiment, mind you... from 4 feet high) was actually pretty controllable. Would think the same would work with webbing. Incidentally, with clothing I weigh about 190 and the paracord did not burn through with the munter, and it's got a lot less material in it than webbing, meaning far more localized hot-spotting than you'd likely get at the contact points of webbing in a munter.

Ascending using friction hitches would make me a bit nervous, as the constriction around the webbing could potentially vary, causing either difficult release and/or unpredictable release. Maybe a friction hitch in combination with backup knots, an ATC as a capture device (in place of the harness hitch), or some other way to prevent a fall should the friction hitch fail. Guess I'll have to go play around in the tree a bit.

Jake T · · Prescott AZ · Joined Jun 2011 · Points: 5

No, the webbing won't cut through itself. Unless of course you have the bad misfortune of using a piece of webbing with suicidal tendencies.

Luckily, psychological disorders are very rare with most reputable climbing equipment brands. although aliens have been known to blow they're own heads off occasionally.

caribouman1052 · · Unknown Hometown · Joined Nov 2012 · Points: 5

Yikes!! I have witnessed nylon cut through nylon; I have seen webbing friction on rope cut through the webbing. Nylon on nylon will generate huge amounts of heat. I don't think that the choice of webbing or rope is the more important, I think it's how you set up the rappel device. Make sure nylon never runs across nylon, and that the combination of device and descending "line" will generate enough friction to get you down safely, and dissipate heat fast enough to not melt through. That said:

Think about it - With a brake bar rig, and webbing as the descent line, why wouldn't it work? Massive heat dissipating surface area, no coiling to endanger a nylon/nylon contact...

I agree with Ryan L - a munter with webbing is a bad idea. (I think munters are a bad idea anyway, given my experience. I know they work, they just scare the *&&^% out of me). I like the idea of doing a weighted webbing-munter test, to see how long it takes to fry. I'd like to catch it on film, and get a clear, visible, postable result.

YMMV.

Kent Richards · · Unknown Hometown · Joined Jan 2009 · Points: 81
caribouman1052 wrote:Make sure nylon never runs across nylon
Aren't ropes made of nylon? Doesn't a rope rub on itself in a munter?

caribouman1052 wrote: I know they work, they just scare the *&&^% out of me
If they work, why are they scary? A lot of people have used munters. I wonder if a rope in a munter has ever melted through itself...
r m · · Unknown Hometown · Joined Apr 2015 · Points: 0
caribouman1052 wrote:I'd like to catch it on film, and get a clear, visible, postable result.
Do it. This thread has at least one post of people just making shit up and speaking definitively about it.

Also, I'd suggest getting over your fear of munters. They're very useful, and superior to tube devices in some situations.
Anonymous · · Unknown Hometown · Joined unknown · Points: 0

You could do this with most anything that would feed the rope through and create some fraction to slow down / lock. Is it ideal? No but if it is an emergency and you go really slow it will be fine.

As far as going back up you would probably be better off lead climbing it (or just climb the rope and every chance you get stopping and putting a simple overhand or something as a backup as if you are rope soloing.

As long as you take it slow and watch everything you can get down without create enough friction to cut the rope. I am sure the way most people tie a slackline would create more friction than a simple repeal one time.

johnnyrig · · Unknown Hometown · Joined Dec 2011 · Points: 105

Here's a crap video from this morning involving a cottonwood, some webbing, ascenders, friction hitches, and paracord.

The webbing worked fine, exhibiting zero heat or abrasion damage during the short (like 10 feet) rappel using a munter hitch.

The paracord, using just a single strand and a monster munter, immediately made weird noises and abraded the sheath in the first foot. It still held, though I wouldn't want to rap a single strand where my life depends on it.

My editing program crashed, as in fubar, so it's the full video shot from a chest mounted gopro. Let me save you some boredom. Skip ahead:

Rappel on webbing using munter at 4:20

Tried to ascend single strand of webbing using 6mm cord, prusik above and klemheist below. Fail. Starts at 7:50

Rappel single strand of paracord using a monster munter at 13:40
.

Should you elect to bore yourself with my poor ascension technique, and my wife getting disgusted with me for not answering the phone and making both of us late for work, that's your own wasted time. Don't say I didn't warn you!

youtu.be/GZ6vPLn2wnE

FYI I weigh about 190 with clothes and harness and crap. Also can't seem to figure out video embedding here. Meh.

Rick Blair · · Denver · Joined Oct 2007 · Points: 266
Ryan L wrote: Webbing has edges unlike rope. Munter hitches would make the webbing cut right through itself and you would fall.
Tubular webbing has edges?
Kent Richards · · Unknown Hometown · Joined Jan 2009 · Points: 81

Johnnyrig, would you be so kind as to do a vid of rapping on 10 girth-hitched skinny dyneema slings?

:-)

Marc801 C · · Sandy, Utah · Joined Feb 2014 · Points: 65

I can't for the life of me imagine why someone would ever have that much webbing with them. Or in their basement for that matter.

Muscrat · · Unknown Hometown · Joined Oct 2011 · Points: 3,625

Why would you have enough webbing to rap on? If you are carrying it for emergencies, carry 8mm cord? Heck, 7 in dire straights (OK correct me here). I guess my question would be how light a cord would you escape on? 5mm? It's rated 5kn....scare the heck outa ya, but....YOU'RE GUNNA DIE!!!
WHY?

johnnyrig · · Unknown Hometown · Joined Dec 2011 · Points: 105

Sure! Send me the slings....

Small diameter cords seem to have their main purpose in some of the techniques used occasionally in the caving and canyoneering communities. In some of the exploratory expeditions it seems, people have left lengths of cord through a top anchor in order to pull a rope back up and through it for ascending out. Not without controversy, or indeed considerable risk.

And then... there's always Bear Gryls.
youtube.com/watch?v=QEBcrtX…

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346
johnnyrig wrote: youtube.com/watch?v=QEBcrtX…
This reminds me of the duck tape myth that Mythbusters did. I recall they made a rope and harness out of duck tape and rappelled down it. From what I can tell, they werent even on a backup either, just the duck tape. Smart.
Cheyenne Wills · · Unknown Hometown · Joined Jan 2006 · Points: 61

A couple of comments..

First question is why... but not for the reasons stated...

The real issue is control of the amount of friction that can be applied to the material and how the material can or cannot be deformed.

Most ascenders/descenders that climbers use are designed to work with material that has a specific diameter range and a circular cross section that resists deforming in that cross section.

First let's look at the characteristics of a rope...

Looking at a cross section of a modern rope, you have a sheath of material covering a core. The sheath acts as a container that restricts how the core can deform in width, preventing the core from crushing flat. Given enough localalized force of course, one can crush a rope to the point that it is cut (same way that given enough localized force, one can use a chisel to 'cut' a metal bar). The sheath provides some linear tinsel strength, but the majority of the linear tinsel strength comes from the core. Without the sheath, the core could be easily deformed to a fairly flat profile.

In addition with dynamic ropes, there must be allowance for linear deformation. It is this controlled deformation that absorbs the energy of a fall. The deformation results in the thinning of the rope. The energy is dissipated as heat along the length of the available rope. The sheath must be able to accommodate this linear deformation. The end result of applying the linear force is a thinner rope that resists deformation in both length and diameter (notice how a rope under tension wants to stay in a circular profile).

Most ascenders/descenders used in climbing utilize the fact that a rope will stay in a fairly circular profile. Descenders (and belay devices) typically work by introducing a bend, or series of bends in the rope over a small radius. It's the resistance of the rope to bending in such a small radius as we'll as contact friction within the device that gives the control we want. Mechanical ascenders mostly work by some sort pinching mechanism. For this to work, the pinching mechanism must stay in full contact with the rope. For friction based ascenders, the requirement is to be able to maintain the necessary contact. For prusik hitches, the diameter of the prusik cord, as well as the number of wraps are are critical in the function.

One interesting point. Jumars have been known to 'fail' if the sheath of the rope is compromised, this is because jumars work by not only pinching, but also by gripping into the sheath with a set of small teeth.

Now looking at flat and tubular webbing.

One of the primary features of webbing is that it can support a small turn radius. In addition the weave of the webbing is typically designed to reduce friction. If we were to fill tubular webbing with a core, we would simply end up with a kernmantle rope. In addition webbing is typically static. From a tinsel strength, 1 inch webbing exceeds the strength of 9.5mm dynamic rope.

So why will webbing not work well with ascenders/descenders used for climbing? Two main reasons. The geometry of webbing isn't compatible with the device, and/or the turn radius doesn't produce enough friction to be usable.

One could design an ascender that works with webbing. In fact a cam strap would work if the buckle was strong enough. A descender could be built as well. A caving "brake rack" might work with enough brake bars.

The whole issue of nylon on nylon applies to both webbing and cordage. The main problem is having a fixed component and a moving component. The moving component 'saws' into the fixed component. This is true for not only nylon, but any material. Simply look at well used rap anchors. The failure would be on the component that maintains constant contact (yes, there is a case if the component gets hot enough to melt the other component first.. i.e a rap ring gets hot enough to melt the running rope).

So... Yes it would be possible to ascend or descend webbing. You just need a mechanism that can work with the geometry of webbing.

To ascend, I suspect a properly sized prusik cord with enough wraps or an ascender built like a cam strap buckle would work.

To descend, a brake bar rack with enough brake bars would work. Also a form of body rappel like a dufelsitz (spelling) with extra wraps around the leg would work as long as you could get the necessary amount of friction needed to stay in control.

Guideline #1: Don't be a jerk.

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