Canyoneering USA Tech Tips

[Dan-wild]

The photos on your biner block page are good, but they are too small. If you click them, they don't enlarge as expected, but instead you're kicked to the top of the page.

Since the problem of rope grooves has been a warm topic lately, perhaps a page about preventing them might be useful. Extended anchors, courtesy anchors and single strap anchors (1 strap of webbing run from an anchor to the edge) don't seem to be techniques most folks use (but should).

I think a page about proper deadman/cairn anchor building would be very helpful. What is the safest way to wrap a rock with webbing? Also, a page about using potshots as retrievable anchors (a la No Kidding) would be cool too.

If you have already built pages on these topics, then never mind. Or maybe they should be moved to your tech tips page.

Overall, cool page! I've used a couple techniques that were learned there.

Bob

Good points! I would also like to see a pointer on the best way to wrap a rock with webbing. This seems to be a very common problem. Nice pic slot machine!

[Brian in SLC]

From what I remember the 1" tubular webbing has a breaking strength of 4000 pounds and the knot at the end reducing that by 25%.

Knot at the end would be more like a 50% reduction in strength. Especially an overhand knot.

[oldno7]

The last canyon we did, the one piece of webbing that we had to leave you set up differently than I have seen it. A slip knot on the end of the webbing with the loop around the end of the tree. So that a single line of webbing extended out and then an overhand knot in the end with the rapid in it. It made sense that you could set up the exact direction of pull on the webbing, and you only had to use approximately half the amount to extend it out from the anchor. From what I remember the 1" tubular webbing has a breaking strength of 4000 pounds and the knot at the end reducing that by 25%. So a single line strength of 3000 lbs when set up that way. Whereas a full loop with water knot would be 4000 + (4000 x .75) for a 7000 lb strength.

I'd be very careful using a "slip" knot. Nylon rubbing on nylon will burn eventually. May be better to tie a static knot while extending a single piece of webbing.
A water knot will also work for this application.

While a "slip" knot may not show wear for some time, it is bad practice to use.

Theres dozens of ways to tie slip knots, many not easy to identify, especially after use.

Theres only one way to tie a water knot.

[trackrunner]

Curious what the Frost knot would be used for with regard to an anchor. Is it to isolate a loop (to put a rapide into)?

I've seen and used a frost knot with two isolated loops in opposite directions. the look facing the anchor was used for a meet backup for marginal anchors you love so much. Also seen used as a courtesy anchor for all but the last.

To be honest I've only used it a couple times in a canyon and vast majority I use the water knot.

[2065toyota]

I'd be very careful using a "slip" knot. Nylon rubbing on nylon will burn eventually. May be better to tie a static knot while extending a single piece of webbing.
A water knot will also work for this application.

While a "slip" knot may not show wear for some time, it is bad practice to use.

Theres dozens of ways to tie slip knots, many not easy to identify, especially after use.

Theres only one way to tie a water knot.

After the webbing tightens to your anchor and pointed in the correct direction there would be little burning of the knot other than sun shining on it. The purpose is being able to extend the webbing using half as much material. The breaking strength of 1" tubing with overhand is much higher than 2000 lbs

Maybe this should be moved to it's own thread as to not hijack Tom's threads for Tech tips linked to his site

[Brian in SLC]

Another often quoted source:

http://user.xmission.com/~tmoyer/tes...ength_Cord.pdf

Yeah, you just about can't make a configuration of 1" webbing with any knot, hitch, loop, etc, that would be "unsafe" especially for body weight type rappelling loads.

Do they still sell 1" webbing? Ha ha.

[oldno7]

The purpose is being able to extend the webbing using half as much material.

This can be accomplished without a "slip" knot

[oldno7]

[QUOTE=2065toyota;519466]After the webbing tightens to your anchor and pointed in the correct direction there would be little burning of the knot other than sun shining on it. QUOTE]

So your using a new type of "no stretch" webbing"?

Sorry--nylon on nylon is a bad choice, if you have other options.

[2065toyota]

There usually are other options. If wrapped around an anchor there isn't going to be very much friction between the webbing. I would say very much less friction that when the webbing rubs on rocks and and other objects it passes by. Obviously this short piece doesn't show the savings in length of webbing but on a wrap that needs to be extended 20' you wouldn't use much more that 21' instead of 41' to do it

[oldno7]

Your length savings is a moot point. As stated previously, extending a single strand of webbing can certainly be strong enough.

The concern is your advocacy for running nylon webbing on nylon webbing. This is NOT a good practice.

But since it's not hitting home, might I ask why you would you need a rapid link in this system?

[2065toyota]

I find it moot that webbing can wrap around sandstone rocks, buried inside cairn anchors with rocks stacked on it, tree bark, steel, and aluminum but you better not ever let it touch itself

[2065toyota]

I do understand your point so we can be done talking about. I appreciate all advice and criticism

[dweaver2130]

Curious what the Frost knot would be used for with regard to an anchor. Is it to isolate a loop (to put a rapide into)?

Water knot is so simple.

I thread my webbing through the bolts, or around a pinch, etc. Then I tie a frost to close that loop. Also when you tie the frost it creates a loop for you to put your quick-link in. I then cut the excess off and repack. You only end up having to tie one knot and that knot creates the loop you need for your link.

[penmartens]

I don't have the time to figure out the frost knot being talked about. Was there a photo that I missed?
As far as the setup Toyota posted up (thanks for the photos), I've been seeing this around in North Wash canyons and wondered what the reasoning was. Last time I was through Angel Slot someone had used this same idea. They must have been concerned about the webbing on webbing aspect that Oldno is worried about because they used 2 rapides; one on the rope end and one on the stationary end avoiding the webbing on webbing situation.We re-rigged using a water knot at the upper end of the setup and walked away with 3 shiny new rapides.
Using a single strand of webbing is acceptable. It is safe and more economical. Your reasoning is sound, it just needs tweaked a little bit.
I guess what I don't like about the setup in the photo is that there is so much play around the rock. Wind and water can really get anchors to whipping around causing wear on the rock and webbing.
Penny

[trackrunner]

Your length savings is a moot point. As stated previously, extending a single strand of webbing can certainly be strong enough.

The concern is your advocacy for running nylon webbing on nylon webbing. This is NOT a good practice.

But since it's not hitting home, might I ask why you would you need a rapid link in this system?

Kurt what do you think about this anchor set up? Photos are from Wyoming Dave over at the canyons group.

The noose with the double fisherman's knot would tighten around the rock and the knot tightens creating a snug no slipping anchor.

from this post
http://groups.yahoo.com/group/canyons/message/62375



Mods maybe time to split this thread into a discussion on nylon on nylon with girth hitch anchors?

[oldno7]

Kurt what do you think about this anchor set up? Photos are from Wyoming Dave over at the canyons group.

The noose with the double fisherman's knot would tighten around the rock and the knot tightens creating a snug no slipping anchor.

from this post
http://groups.yahoo.com/group/canyons/message/62375



Mods maybe time to split this thread into a discussion on nylon on nylon with girth hitch anchors?

Why split?? Tom mentioned earlier he uses this method quite a bit and it may not be condoned by others. Seems appropriate here.

I don't see the "potential" weakness in the knot as much as the "burning" of the loop as a result of your load end cycling through said loop.

I'm sure we all have watched webbing stretching while a rappeler is on line, stretching an inch is quite easily accomplished and at times more depending on your length of webbing. The fact it is cynched against a tree/rock etc does not completely mitigate this action.

I used to always demonstrate in courses I taught, the ability of rope to cut through webbing while applying some pressure, could do it in under 20 seconds.

I will grant you that webbing "may" not create as much friction sliding through a webbing loop as rope, BUT I deem this as bad practice overall, tom does not.

As with everything in life, you are ultimately responsible for yourself, relying on internet advice that YOU have not personally deemed safe might leed to broken bones.

This was toms response to using a slip knot in webbing, earlier in this thread.

"I consider the way I set that up to be a "standard method", though many others would not. To me, it is a better solution for a long-webbing rigging situation, as it leaves less crap in the canyon."

Tom

[PG Rob]

I don't have the time to figure out the frost knot being talked about. Was there a photo that I missed?

I posted some pictures earlier in the thread.

Here they are again:

[penmartens]

Rob,
Thanks for your patience and for reposting the pics. I view Bogley only from my new phone and the images were showing as a link.
This is a nifty setup. I usually do single strand, but will give this a try next time I'm doing a loop of webbing around a base.
Penny

[2065toyota]

What is the strength difference between the standard tubular webbing used for building anchors and some ICG 6mm static line pull cord? Price point is about the same. The pull cord is much more abrasion and water resistant. Could it be used instead of the traditional webbing for rap setups? Just a thought.

[ratagonia]

What is the strength difference between the standard tubular webbing used for building anchors and some ICG 6mm static line pull cord? Price point is about the same. The pull cord is much more abrasion and water resistant. Could it be used instead of the traditional webbing for rap setups? Just a thought.

The tubular webbing is MUCH better going over an edge.

The part against the rock stays put, the outside layer can slide back and forth a little bit.

A hard round cord, like the pull cord or my ropes, puts a lot of stress on the inside of the curve where it crosses an edge. Tends to cut through the sheath there.

Which is why we use tubular webbing.

Not like you can't use rope or cord in an emergency, but it will not last as long as the tubular webbing.

Tom