What happened in Heaps Canyon??

[moabfool]

Brian: concerning the discussion on the large rapides. I know for a fact that the one in Mystery is serving no purpose whatsoever. There is a medium sized one that does just great. The overly large one is just an accident ready to happen.

Serving no purpose? Isn't it the rappel anchor point? That's not "no" purpose, but, a primary one?

Only an accident waiting to happen if you biner block?

Otherwise, if you rappel on two cords tied together (or, maybe a 70m rope doubled), then that big rapide would work just fine.

In the climbing world, big rapides are considered better. But, climbers rarely (if ever) biner block.

I just hate the thought that a technique is forcing the rappel anchors to be smaller and less strong, with more friction and more chance of sticking a rope, and less useful life from a wear standpoint. Plus, any diameter rope will be fine in a large rapide, versus, some small rapides will have a hard time accomodating a large diameter rope.

I'll say, that if the only advantage to a smaller rapide is that it accomodates a biner block, then, find another technique to use.

Plus, you get more friction from two ropes when you rappel. Easier to control. Less chance for wear (sheath burn throughs) on one rope.

-Brian in SLC

All good points, but the fact is, as was demonstrated by the accident that precipitated this thread, that people are going to see a technique demonstrated and then they are going to apply that technique broadly. These people may lack the skills, judgment, and insight to see that what they are about to do is unsafe. "There is nothing so uncommon as common sense," -Frank Lloyd Wright.

I'm not saying that our unfortunate victim wouldn't have picked up on the problem under normal circumstances. What I am saying is that when one is cold, fatigued, and presented with a close view of their goal (the bottom) they do not always think clearly/make rational judgments. At that point only rules and ingrained training/practice can keep you safe as logic and reasoning will not do so.

I guess my point is this: People are going to use this technique (biner block) who don't necessarily know when it is inappropriate to use. The outcome will likely be injury or death. As a result we need to play to the lowest common denominator. Sure a thinner quicklink will wear more quickly than a girthy one. And? It's the responsibility of the individual canyoneer to come equipped with a workable alternative.

[jumar]

Or do they usually rappel double strand? If that is the case then I suppose the knot doesn't necessarily have to block right next to the rapide.

I usually double strand.
I climbed for about 8 years before I started officially canyoneering, so I guess old habits die hard.

[Brian in SLC]

In the climbing world, big rapides are considered better. But, climbers rarely (if ever) biner block.

Or do they usually rappel double strand? If that is the case then I suppose the knot doesn't necessarily have to block right next to the rapide.

I've never seen a climber use a biner block on a rappel.

They typically rappel double strand.

-Brian in SLC

[hesse15]

Brian,
you have to consider that a lot of people join this sport try to get as light as possible
and the biner block allow them to use the other strand with whatsoever.
the last crazy i heard was pulling the rope using a fish line!!!!

in a way i like the double real rope , also because if anything happens you have a rope not a shoe string to rap off.

unlikely i cannot carry the weight, but i do not understand in this sport people that brag about been superman strong and after they cry if they have to carry a 60meter 9mm rope.



i agree that biner block can be useful in a waterfall or better a contigency anchor that you can lower who get stuck
or in small drops, but made a rule 100% i think is just wrong.
but that is the actual trend

Brian: concerning the discussion on the large rapides. I know for a fact that the one in Mystery is serving no purpose whatsoever. There is a medium sized one that does just great. The overly large one is just an accident ready to happen.

Serving no purpose? Isn't it the rappel anchor point? That's not "no" purpose, but, a primary one?

Only an accident waiting to happen if you biner block?

Otherwise, if you rappel on two cords tied together (or, maybe a 70m rope doubled), then that big rapide would work just fine.

In the climbing world, big rapides are considered better. But, climbers rarely (if ever) biner block.

I just hate the thought that a technique is forcing the rappel anchors to be smaller and less strong, with more friction and more chance of sticking a rope, and less useful life from a wear standpoint. Plus, any diameter rope will be fine in a large rapide, versus, some small rapides will have a hard time accomodating a large diameter rope.

I'll say, that if the only advantage to a smaller rapide is that it accomodates a biner block, then, find another technique to use.

Plus, you get more friction from two ropes when you rappel. Easier to control. Less chance for wear (sheath burn throughs) on one rope.

-Brian in SLC

[Brian in SLC]

I guess my point is this: People are going to use this technique (biner block) who don't necessarily know when it is inappropriate to use. The outcome will likely be injury or death. As a result we need to play to the lowest common denominator. Sure a thinner quicklink will wear more quickly than a girthy one. And? It's the responsibility of the individual canyoneer to come equipped with a workable alternative.

Yep.

I've given this a fair bit of thought over the last while. Seems like if you had to knot and/or biner block a drop, you could carry a rigging plate or some type of rescue belay plate (I've got a few CMI ones, small hole in the middle, notches on the outside for the rope to sit against, probably a three or four inch diameter plate).

http://www.rescueresponse.com/store/...-anch-rig.html

Yates model above looks kinda cool.

Anyhoo, you could slip one of these onto the rope, then knot or biner block against it, which would be against a larger diameter rapide. As a large disc, it would sit nice and flush against the rapide with less chance of a hang up.

Folks could also still complete the loop on these biner blocks by clipping back into the rappel line.

I've never understood the need for a biner block when there isn't a knot to pass. There are some situations where you want to block one side of the rope in case you need to ascend it, or, to get the rappel line to follow a pull cord (by clipping it back through the rap line). But, for standard rappels, I'm not sure why its become so common, except that canyoneers not coming into canyons via climbing have learned this technique and dogmatically follow it.

-Brian in SLC

[moabfool]

I guess my point is this: People are going to use this technique (biner block) who don't necessarily know when it is inappropriate to use. The outcome will likely be injury or death. As a result we need to play to the lowest common denominator. Sure a thinner quicklink will wear more quickly than a girthy one. And? It's the responsibility of the individual canyoneer to come equipped with a workable alternative.

Yep.

I've given this a fair bit of thought over the last while. Seems like if you had to knot and/or biner block a drop, you could carry a rigging plate or some type of rescue belay plate (I've got a few CMI ones, small hole in the middle, notches on the outside for the rope to sit against, probably a three or four inch diameter plate).

http://www.rescueresponse.com/store/...-anch-rig.html

Yates model above looks kinda cool.

Anyhoo, you could slip one of these onto the rope, then knot or biner block against it, which would be against a larger diameter rapide. As a large disc, it would sit nice and flush against the rapide with less chance of a hang up.

Folks could also still complete the loop on these biner blocks by clipping back into the rappel line.

I've never understood the need for a biner block when there isn't a knot to pass. There are some situations where you want to block one side of the rope in case you need to ascend it, or, to get the rappel line to follow a pull cord (by clipping it back through the rap line). But, for standard rappels, I'm not sure why its become so common, except that canyoneers not coming into canyons via climbing have learned this technique and dogmatically follow it.

-Brian in SLC

I appolgize. I used circular logic there. I effectively said, "There are people who don't know that we have to think about, but they should know and be prepared." Oh well, people drive that don't know the rules of the road. What can you do?

I do agree, people use the biner block too much. In most situations rappelling double strand will work just fine. Hesse does have a point though. Why carry two full length ropes when one, and a pull cord, will do fine? Both cases have merit. The ultimate point is that if you have the skills to pull it off then have at it. If you don't, you may be a candidate for the Darwin Award.

[Brian in SLC]

I do agree, people use the biner block too much. In most situations rappelling double strand will work just fine. Hesse does have a point though. Why carry two full length ropes when one, and a pull cord, will do fine? Both cases have merit. The ultimate point is that if you have the skills to pull it off then have at it. If you don't, you may be a candidate for the Darwin Award.

I rap double strand with my 6mm pull cord all the time. Usually feeding it on the go out of its little bag.

A fully functional pull cord, IMHO, should be able to function on its own in a pinch.

My old Espirit alpine escape rope kinda bit the dust (er, the dust bit the rope, rockfall chopped it). Now I've got a sweet BW chunk of 6mm kevlar that has the nicest hand...and...no worries about its strength...

-Brian in SLC

[ajroadtrips]

I rap double strand with my 6mm pull cord all the time. Usually feeding it on the go out of its little bag.

A fully functional pull cord, IMHO, should be able to function on its own in a pinch.

My old Espirit alpine escape rope kinda bit the dust (er, the dust bit the rope, rockfall chopped it). Now I've got a sweet BW chunk of 6mm kevlar that has the nicest hand...and...no worries about its strength...

-Brian in SLC

Hmmm, that peaks my interest. I rap double if I have the rope, biner block and pull cord with a 6MM if I don't. You are tying your 6mm pullcord to your "bigger" rope, then rapping double strand?

Tom's 6MM pull cord is rated on his site at 2200 lbs. Does that seem strong enough? Doesn't an overhand reduce the strength of the rope by a large percentage?

[Iceaxe]

A rough look at the numbers.... Tom rates his 8mm at 3900 lbs and his 6mm at 2200 lbs.... so a 6mm doubled is stronger then 8mm single in strength?

My preferred canyon setup has become two 100' 8mm ropes. This works for most canyons (outside Zion) and allows the group to split the weight, rap double strand, and leap frog the ropes at the smaller drops.

[Brian in SLC]

Hmmm, that peaks my interest. I rap double if I have the rope, biner block and pull cord with a 6MM if I don't. You are tying your 6mm pullcord to your "bigger" rope, then rapping double strand?

All the time. I find it feeds nicely through the other slot of an ATC, too. Plus, when I deploy it as I rappel out of a bag, I control the length incrementaly, rather than "bombs away" by tossing the whole bag down, which, may not be good if I'm aiming for ledge and rap anchor off the ground aways, and I don't want that extra feet of rope (and bag) below me if there are wind concerns or stuff for the rope to get stuck on.

Tom's 6MM pull cord is rated on his site at 2200 lbs. Does that seem strong enough? Doesn't an overhand reduce the strength of the rope by a large percentage?

IMHO, for rappelling, that rope on Tom's site at 6mm would be well strong enough for a rappel, even with a knot in it. Given that, I wouldn't care to ascend it single, nor do a haul and/or rescue (ie a pick off) off it, so, I'd recognize those limitations for sure.

Overhand might take 40% out for strength. I always assume 50% for margin. But, you're not really on that knot directly either, especially on a rappel anchor. Be unusual to completely load that single strand with the knot directly in line to the load. And, if I do end up rappelling the pull cord, its usually doubled. Or, if single strand, then I need to be a bit more aware of any shock load potential and the effect a knot might have at the anchor.

-Brian in SLC

[jumar]

Why carry two full length ropes when one, and a pull cord, will do fine?

My concern has always been not getting my rope stuck. Having a knot or biner I'm pulling down, seems much more likely to get caught, then just a untied strand. This is assuming of course that you're using only one rope, doubled over. I'm wary of doing a biner block on any rap without a very clean pull, because I don't want to get my rope stuck. Are my fears not as bad as I think? But I rarely have a problem double strand-ing so I haven't bothered to switch.

[smcqueen]

It seems to me that some kind of block is very nice for setting rope lengths so you don't have to stuff the whole rope in the bag, or for floating disconnects. Otherwise, rapping on a double rope is fine. I usually have a 60M 9mm plus a 60M 6mm pull cord. I've never tried rapping on them both together. I also frequently clip the block biner back into the rappel rope for safety, unless I'm concerned about the pull. For the last drop in Behunin, we used a single biner block, not clipped back. I went down first and carried the rope bag with me until I got to the free part. The last guy down brought down the pull cord with him. At the bottom, we attached jumars to the pull cord and pulled with no problem.

We actually had two 60M ropes plus the pull cord in Behunin and were able to leapfrog teams on the multi-stage drops. It worked very nicely. We always used some kind of block. I don't think we ever rapped double rope.

[moabfool]

Overhand might take 40% out for strength. I always assume 50% for margin. But, you're not really on that knot directly either, especially on a rappel anchor. Be unusual to completely load that single strand with the knot directly in line to the load. And, if I do end up rappelling the pull cord, its usually doubled. Or, if single strand, then I need to be a bit more aware of any shock load potential and the effect a knot might have at the anchor.

-Brian in SLC

Relative reduction in breaking strength of single kernmantle rope at knot:

Double Fisherman's 15-30%
Clove Hitch (biner block) 15-20%
Fisherman's 15-20%
Overhand Knot (EDK) 15-20%
Water Knot aka. Ring Bend 20-30%
Figure Eight 20-30%
Bowline 25-30%

Source: American Alpine Journal
My source: Mountaineering, Freedom of the Hills, Ed. 7 p. 141

Okay, it's not an exact quote. I added the parenthetical comments.

[hank moon]

Overhand might take 40% out for strength. I always assume 50% for margin. But, you're not really on that knot directly either, especially on a rappel anchor. Be unusual to completely load that single strand with the knot directly in line to the load. And, if I do end up rappelling the pull cord, its usually doubled. Or, if single strand, then I need to be a bit more aware of any shock load potential and the effect a knot might have at the anchor.

-Brian in SLC

Relative reduction in breaking strength of single kernmantle rope at knot:

Double Fisherman's 15-30%
Clove Hitch (biner block) 15-20%
Fisherman's 15-20%
Overhand Knot (EDK) 15-20%
Water Knot aka. Ring Bend 20-30%
Figure Eight 20-30%
Bowline 25-30%

Source: American Alpine Journal
My source: Mountaineering, Freedom of the Hills, Ed. 7 p. 141

Okay, it's not an exact quote. I added the parenthetical comments.

These results are not reproducible - anticipated 50% loss is prudent.