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So it's been 5-6 years since John Long's "Climbing Anchors" 2nd edition came out, advocating the equalette as the best method for equalising forces in anchor systems.
Yet a search for "Equalette" on these forums only returns 9 results.
What have your experiences been with the equalette? Have you heard of it? Have you ever used it? Do you use it every time? Do you trust it?
So far in the forums, it's usually mentioned as an aside, just wondering why that is?
Yet a search for "Equalette" on these forums only returns 9 results.
What have your experiences been with the equalette? Have you heard of it? Have you ever used it? Do you use it every time? Do you trust it?
So far in the forums, it's usually mentioned as an aside, just wondering why that is?
In reply to DeShark:
Not really played around with one, from my dim memories I can think about the question of shock loading in the case of an anchor failing?????
http://www.paulraphaelson.com/downloads/acr.pdf
Is even more wacky, again the shockloading issue.
Not really played around with one, from my dim memories I can think about the question of shock loading in the case of an anchor failing?????
http://www.paulraphaelson.com/downloads/acr.pdf
Is even more wacky, again the shockloading issue.
In reply to Simon Wells:
I don't really understand what the problem is with so-called shock loading. If one piece of protection fails, then the same force is transferred onto the remaining piece(s). It doesn't increase the original force (it will decrease it in fact). Also, the equalette has limiter knots specifically designed to reduce the extension (and hence shock loading).
The bigger problem that I see in the ACR is that if the cord fails, then the whole anchor fails.
I don't really understand what the problem is with so-called shock loading. If one piece of protection fails, then the same force is transferred onto the remaining piece(s). It doesn't increase the original force (it will decrease it in fact). Also, the equalette has limiter knots specifically designed to reduce the extension (and hence shock loading).
The bigger problem that I see in the ACR is that if the cord fails, then the whole anchor fails.
In reply to DeShark:
The extension/shock-load problem is as follows: Take the simplest crap belay, two bits of gear linked with a sling, you're clipped and hanging from the sling. The obviously (and inobviously) dangerous American death triangle. Your partner falls, let's assume seconding. In the USA on shiny bolts you'd be fine, here in the UK one of your rusty belay pegs is overloaded and crumbles. You drop a couple of foot, the sling pulls tight on the thread you clipped as your second belay piece, the shock-load force isn't huge, maybe 10-15kN but the thread tat won't take it. That's the extension problem in a nutshell.
Unplanned extension of slings (eg partially failed sliding x) isn't generally a huge concern where they're part of a running belay but when you're hanging from them it's a different matter.
Anyway... no I haven't tried an equalette, I generally use my rope and it works very well.
jk
The extension/shock-load problem is as follows: Take the simplest crap belay, two bits of gear linked with a sling, you're clipped and hanging from the sling. The obviously (and inobviously) dangerous American death triangle. Your partner falls, let's assume seconding. In the USA on shiny bolts you'd be fine, here in the UK one of your rusty belay pegs is overloaded and crumbles. You drop a couple of foot, the sling pulls tight on the thread you clipped as your second belay piece, the shock-load force isn't huge, maybe 10-15kN but the thread tat won't take it. That's the extension problem in a nutshell.
Unplanned extension of slings (eg partially failed sliding x) isn't generally a huge concern where they're part of a running belay but when you're hanging from them it's a different matter.
Anyway... no I haven't tried an equalette, I generally use my rope and it works very well.
jk
In reply to jkarran:
So in summary, the extension "problem" is only a problem when:
-You're tied in directly with a static sling/cord (which you shouldn't do)
-Your placements are so sketchy they fail to hold forces generated by a second (which they shouldn't do)
> you're clipped and hanging from the sling.
So in summary, the extension "problem" is only a problem when:
-You're tied in directly with a static sling/cord (which you shouldn't do)
-Your placements are so sketchy they fail to hold forces generated by a second (which they shouldn't do)
In reply to DeShark:
Why wouldn't you do that? There's nothing wrong with being clipped directly to a properly assembled 'static' belay.
Uncontrolled extension due to anchor failure is obviously only a problem if an anchor fails. Anchors do fail, compromises and mistakes are made.
Uncontrolled extension of a running belay is a problem if that additional extension means you hit something.
jk
> So in summary, the extension "problem" is only a problem when:
> -You're tied in directly with a static sling/cord (which you shouldn't do)
> -You're tied in directly with a static sling/cord (which you shouldn't do)
Why wouldn't you do that? There's nothing wrong with being clipped directly to a properly assembled 'static' belay.
> -Your placements are so sketchy they fail to hold forces generated by a second (which they shouldn't do)
Uncontrolled extension due to anchor failure is obviously only a problem if an anchor fails. Anchors do fail, compromises and mistakes are made.
Uncontrolled extension of a running belay is a problem if that additional extension means you hit something.
jk
In reply to DeShark:
OK try this for an experiement.
Take two strong friends, one length of dynamic rope, one length of static rope / cord.
Get the two friends to become the gear (bolt/ nut etc ) in a two point belay by each one holdng a hms / crab set up any type of belay. Load the 'belay' by leaning in it so your two pieced of gear / bolts (your friends) take the load. One lets go!!!! Let the surviving gear / friend describe the load.
Now do the same with a static rope / cord, the same belay 'failure', with the same friend / gear taking the force. Ask the shock loaded friend which load was bigger?
Chances are they will not be able to distinguish a difference if the angles and lengths are all the same.
Now do the do same but use the static cord as a giant sling, one end on each friend / gear and simply clip the middle. Then let the same gear / friend fail and load the same remaining friend and see what happens..........
Ask the shock loaded friend to rate the force of each 'failed belay'. You may well find the third system creates a significant shock load. That is the danger with the equalette, especialy on trad gear. No amount of dynamic rope in the set up will reduce the forces in a meaning full real life enviroment.
I do this a lot (about once a week!) with other 'games' to help clients / students understand why and how to set up belays. Complex KN equations and stuff are interesting but can lose the real life appilcation of finding that your 50kg mate can pull you over on the third and last experiement.
Enjoy!
OK try this for an experiement.
Take two strong friends, one length of dynamic rope, one length of static rope / cord.
Get the two friends to become the gear (bolt/ nut etc ) in a two point belay by each one holdng a hms / crab set up any type of belay. Load the 'belay' by leaning in it so your two pieced of gear / bolts (your friends) take the load. One lets go!!!! Let the surviving gear / friend describe the load.
Now do the same with a static rope / cord, the same belay 'failure', with the same friend / gear taking the force. Ask the shock loaded friend which load was bigger?
Chances are they will not be able to distinguish a difference if the angles and lengths are all the same.
Now do the do same but use the static cord as a giant sling, one end on each friend / gear and simply clip the middle. Then let the same gear / friend fail and load the same remaining friend and see what happens..........
Ask the shock loaded friend to rate the force of each 'failed belay'. You may well find the third system creates a significant shock load. That is the danger with the equalette, especialy on trad gear. No amount of dynamic rope in the set up will reduce the forces in a meaning full real life enviroment.
I do this a lot (about once a week!) with other 'games' to help clients / students understand why and how to set up belays. Complex KN equations and stuff are interesting but can lose the real life appilcation of finding that your 50kg mate can pull you over on the third and last experiement.
Enjoy!
In reply to Simon Wells:
>No amount of dynamic rope in the set up will reduce the forces
Of course it will: 2 ft of dynamic rope + 0.5 ft of extension is the same as factor 0.25 fall on the anchor. This would correspond to something like 4 kN. Yes, you then have to factor in the effect of the second's fall on top of this, but it's not the same as a 0.5 ft fall onto a static system (which would generate more than 4kN).
I'm not saying that the equalette is a great system in all cases, but with dodgy pro, I'd argue that Equalisation was more important that No Extension if you have some dynamic rope in the system - I think it makes anchor failure less likely in the first place. Protection is better than cure, so to speak. That way, you're less likely to get a cascade failure. I don't know why you wouldn't tie in with the rope.
The extension vs equalisation debate is an old one, I was just after people's experience with the equalette. Looks like it's not popular then...
>No amount of dynamic rope in the set up will reduce the forces
Of course it will: 2 ft of dynamic rope + 0.5 ft of extension is the same as factor 0.25 fall on the anchor. This would correspond to something like 4 kN. Yes, you then have to factor in the effect of the second's fall on top of this, but it's not the same as a 0.5 ft fall onto a static system (which would generate more than 4kN).
I'm not saying that the equalette is a great system in all cases, but with dodgy pro, I'd argue that Equalisation was more important that No Extension if you have some dynamic rope in the system - I think it makes anchor failure less likely in the first place. Protection is better than cure, so to speak. That way, you're less likely to get a cascade failure. I don't know why you wouldn't tie in with the rope.
The extension vs equalisation debate is an old one, I was just after people's experience with the equalette. Looks like it's not popular then...
In reply to DeShark: I'm going to use that one simon! Cheers.
In reply to DeShark:
"Of course it will: 2 ft of dynamic rope + 0.5 ft of extension is the same as factor 0.25 fall on the anchor. This would correspond to something like 4 kN. Yes, you then have to factor in the effect of the second's fall on top of this, but it's not the same as a 0.5 ft fall onto a static system (which would generate more than 4kN)."
I think you have missed the point I was trying to make, apologies for not be clear enough.
In a real life situation the shock load created by an unequalised belay failing is very high, high enough for the belay to fail. From my understanding the Equalette will cause a shock loading.
Using dynamic rope as an equalette or puting dynamic rope as part of an Equalette is unlikely to have enough dynamisn to reduce the shock load to an accecpetable level.
So, experement 3 in my little teaching aids with a dynamic rope as the Equalette or as part of the system will still create enough force to pull the surviving friend / gear over.
"but with dodgy pro, I'd argue that Equalisation was more important"
I have no doubt in some situation that might be true, but as a general rule of thumb the high force created by a single failier of a multi point belay in a Eqaulette would put to high a force on the remaining gear.
If I was to use a Equalette it would be on two good bolts! I have seen European guides use a similar system on bolt belays. But for multiple poor gear belays I would want no shock loading. So while a scenerio can be thought up for an Equalette being a better soloution, I suspect in most cases a KISS (Keep It Simple SImon) soloutio is more affective at creating safe belays.
"Of course it will: 2 ft of dynamic rope + 0.5 ft of extension is the same as factor 0.25 fall on the anchor. This would correspond to something like 4 kN. Yes, you then have to factor in the effect of the second's fall on top of this, but it's not the same as a 0.5 ft fall onto a static system (which would generate more than 4kN)."
I think you have missed the point I was trying to make, apologies for not be clear enough.
In a real life situation the shock load created by an unequalised belay failing is very high, high enough for the belay to fail. From my understanding the Equalette will cause a shock loading.
Using dynamic rope as an equalette or puting dynamic rope as part of an Equalette is unlikely to have enough dynamisn to reduce the shock load to an accecpetable level.
So, experement 3 in my little teaching aids with a dynamic rope as the Equalette or as part of the system will still create enough force to pull the surviving friend / gear over.
"but with dodgy pro, I'd argue that Equalisation was more important"
I have no doubt in some situation that might be true, but as a general rule of thumb the high force created by a single failier of a multi point belay in a Eqaulette would put to high a force on the remaining gear.
If I was to use a Equalette it would be on two good bolts! I have seen European guides use a similar system on bolt belays. But for multiple poor gear belays I would want no shock loading. So while a scenerio can be thought up for an Equalette being a better soloution, I suspect in most cases a KISS (Keep It Simple SImon) soloutio is more affective at creating safe belays.
In reply to jezb1:
No worries, just paypal me 5p each time you use it!
I also get the human anchor to stand at 180 degrees (ie rope in a straight line betwen them) then pull them over! Put them at 60 degrees (ie a V) and I struggle to even make them shuffle forwad. Helps people REALLY understand angles in belays.
That ones is also 5p per use!
No worries, just paypal me 5p each time you use it!
I also get the human anchor to stand at 180 degrees (ie rope in a straight line betwen them) then pull them over! Put them at 60 degrees (ie a V) and I struggle to even make them shuffle forwad. Helps people REALLY understand angles in belays.
That ones is also 5p per use!
In reply to Simon Wells:
Simon, this is something I too am confused about. Your experiment is I think similar to having a second hanging on the rope, then part of the belay failing, them falling the length of the extension (normally less than 0.5 metres) and the remaining anchor point taking the load (with the rope to the second doing its normal shock absorbing magic). Assuming I'm got that correct, the force on the remaining anchor is no more than if a second falls off with 0.5 metres of slack in the rope. Although it is good to keep the rope tightish at all times, this seems a fairly normal situation, and not a surprising "shock load". Even if there is only 2m of rope to the second this would only be a factor 0.5/2=0.25 fall. Assuming limiter knots were being used in any sliding-x style rig, the extension will hopefully only be around 20cm, and possibly only 10cm. These are such small distances that it is unrealistic to think that the rope to the second will not often have an equivalent amount of slack in it at the end of each move, and hence regularly "shock load" the anchor to exactly the same amount.
If the belay is to have any chance of talking a lead fall on the next pitch, or really to be up to much, it should be able to take the second falling 0.5m, do you not think? If the gear really is that bad, another anchor might be the answer, not trying to remove the possibility of a very minor shock load.
Unless I'm on bolts, or about to haul something, I almost always tie in with the rope anyhow, but I have always considered that if things start to fall apart with a sling-based set up, the key concept is to limit the "shock" to no more than that might be experienced by the anchor from a second falling off unexpectedly with some slack out.
Simon, this is something I too am confused about. Your experiment is I think similar to having a second hanging on the rope, then part of the belay failing, them falling the length of the extension (normally less than 0.5 metres) and the remaining anchor point taking the load (with the rope to the second doing its normal shock absorbing magic). Assuming I'm got that correct, the force on the remaining anchor is no more than if a second falls off with 0.5 metres of slack in the rope. Although it is good to keep the rope tightish at all times, this seems a fairly normal situation, and not a surprising "shock load". Even if there is only 2m of rope to the second this would only be a factor 0.5/2=0.25 fall. Assuming limiter knots were being used in any sliding-x style rig, the extension will hopefully only be around 20cm, and possibly only 10cm. These are such small distances that it is unrealistic to think that the rope to the second will not often have an equivalent amount of slack in it at the end of each move, and hence regularly "shock load" the anchor to exactly the same amount.
If the belay is to have any chance of talking a lead fall on the next pitch, or really to be up to much, it should be able to take the second falling 0.5m, do you not think? If the gear really is that bad, another anchor might be the answer, not trying to remove the possibility of a very minor shock load.
Unless I'm on bolts, or about to haul something, I almost always tie in with the rope anyhow, but I have always considered that if things start to fall apart with a sling-based set up, the key concept is to limit the "shock" to no more than that might be experienced by the anchor from a second falling off unexpectedly with some slack out.
1
In reply to David Coley:
Sorry Dave I am being a bit thick, I have reread your post a number of times and still can't get it straight in my head. I think the baby-induced lack of sleep is kicking in!
1) The experiential learning 'games' are to teach climbers at the bottom of the crag how and why to set up belays in a way they will clearly understand and know how to apply the principles.
2) It is not meant to show how falling seconds affect belays
3) It is often the rock that fails at the point of belay not the gear, so let as take as a general rule these concepts:
a) We can only visually assess the gear placements
b) Cracks are areas of weakness in the rock, that is why / how they form
c) We are putting rated and tested gear into an area we can only visually assess and we know they may be weak
So with these points in mind lets think of the golden rule of a belay system is to pass the LEAST amount of force possible. As, in reality we have only a guess at the failure point of the rock.
All the KN type maths is interesting but with trad and to a certain extent bolts we area assuming the rock is going to take the force.
"If the gear really is that bad, another anchor might be the answer, not trying to remove the possibility of a very minor shock load."
Yes more gear means more surface area, more surface area means the same amount of force (if equalised properly) going through a larger area, so less chance of rock failure. Even a minor shock load increases the amount going through the surface area of the gear into the rock, so it would increase the chance of failure in a real life belay.
Its very easy to get into a KN maths game that assumes the rock will not fail and so view the weakest link in the chain as X piece of equipment. When one of the main aims of the belay is to keep the team safe by transferring the least amount of force onto the gear.
I often think that climbers need to understand:
"Rule are for the guidance of the wise and the abeyance of fools"
Or anther way is, understand the concepts and real issues and then adapt your approach.
Hope this helps
PS anyone know how to calm a teething baby? Tried amber, tried bongela , tried singing, walking with the wee beastie in my arms....
Sorry Dave I am being a bit thick, I have reread your post a number of times and still can't get it straight in my head. I think the baby-induced lack of sleep is kicking in!
1) The experiential learning 'games' are to teach climbers at the bottom of the crag how and why to set up belays in a way they will clearly understand and know how to apply the principles.
2) It is not meant to show how falling seconds affect belays
3) It is often the rock that fails at the point of belay not the gear, so let as take as a general rule these concepts:
a) We can only visually assess the gear placements
b) Cracks are areas of weakness in the rock, that is why / how they form
c) We are putting rated and tested gear into an area we can only visually assess and we know they may be weak
So with these points in mind lets think of the golden rule of a belay system is to pass the LEAST amount of force possible. As, in reality we have only a guess at the failure point of the rock.
All the KN type maths is interesting but with trad and to a certain extent bolts we area assuming the rock is going to take the force.
"If the gear really is that bad, another anchor might be the answer, not trying to remove the possibility of a very minor shock load."
Yes more gear means more surface area, more surface area means the same amount of force (if equalised properly) going through a larger area, so less chance of rock failure. Even a minor shock load increases the amount going through the surface area of the gear into the rock, so it would increase the chance of failure in a real life belay.
Its very easy to get into a KN maths game that assumes the rock will not fail and so view the weakest link in the chain as X piece of equipment. When one of the main aims of the belay is to keep the team safe by transferring the least amount of force onto the gear.
I often think that climbers need to understand:
"Rule are for the guidance of the wise and the abeyance of fools"
Or anther way is, understand the concepts and real issues and then adapt your approach.
Hope this helps
PS anyone know how to calm a teething baby? Tried amber, tried bongela , tried singing, walking with the wee beastie in my arms....
In reply to Simon Wells:
>Using dynamic rope as an equalette or puting dynamic rope as part of an Equalette is unlikely to have enough dynamisn to reduce the shock load to an acceptable level.
I don't know why you think that dynamic rope can't handle dynamic forces and reduce them to manageable levels: it's what they're designed for. It's like extending the climbing rope directly to the anchor. Ordinarily, we expect lead forces (which are higher than forces generating when seconding) to be held by one piece of pro (which is effectively set up as a redirected belay, thus multiplying the load by a factor of nearly 2).
The worrying shock loads are a result of static cord as in the case where a belayer has tied in with static cord/sling and then fall factor 2s on the anchor. That can and will snap the sling/krab/belayer/whatever like it's made of butter.
>So, experiment 3 in my little teaching aids with a dynamic rope as the Equalette or as part of the system will still create enough force to pull the surviving friend / gear over.
Yeah, but your friends aren't field tested to withhold 14kN of force. I doubt it'd take more than 0.3kN (i.e. 30kg) to pull someone over.
>If I was to use a Equalette it would be on two good bolts!
Why bother? Just clip them with a sling tied as a cordelette and be done with it. The importance of equalisation isn't as strong with bolts and the lack of extension is probably more important. I'd say you have it the wrong way round.
P.S. I've heard some whisky rubbed in the gums might work. More seriously though, maybe try propping the wee one's head up; I've heard that fluid can build up in the head causing discomfort.. Also, sugar is apparently an anaesthetic for babies, so maybe some sugar water?
>Using dynamic rope as an equalette or puting dynamic rope as part of an Equalette is unlikely to have enough dynamisn to reduce the shock load to an acceptable level.
I don't know why you think that dynamic rope can't handle dynamic forces and reduce them to manageable levels: it's what they're designed for. It's like extending the climbing rope directly to the anchor. Ordinarily, we expect lead forces (which are higher than forces generating when seconding) to be held by one piece of pro (which is effectively set up as a redirected belay, thus multiplying the load by a factor of nearly 2).
The worrying shock loads are a result of static cord as in the case where a belayer has tied in with static cord/sling and then fall factor 2s on the anchor. That can and will snap the sling/krab/belayer/whatever like it's made of butter.
>So, experiment 3 in my little teaching aids with a dynamic rope as the Equalette or as part of the system will still create enough force to pull the surviving friend / gear over.
Yeah, but your friends aren't field tested to withhold 14kN of force. I doubt it'd take more than 0.3kN (i.e. 30kg) to pull someone over.
>If I was to use a Equalette it would be on two good bolts!
Why bother? Just clip them with a sling tied as a cordelette and be done with it. The importance of equalisation isn't as strong with bolts and the lack of extension is probably more important. I'd say you have it the wrong way round.
P.S. I've heard some whisky rubbed in the gums might work. More seriously though, maybe try propping the wee one's head up; I've heard that fluid can build up in the head causing discomfort.. Also, sugar is apparently an anaesthetic for babies, so maybe some sugar water?
In reply to DeShark:
Part of the problem with these discussions is that shock-loading is an undefined term. Part of the problem with it being undefined is that the term has acquired a negative sense: shock loading has to be bad.
It would be better if the term was simply banished from the discussion. The question is what happens when extendible anchor rigging (equalette, ACR, sliding X, Trango Alpine Equalizer) extends under a load that causes the failure of a piece. The "what happens" has to be evaluated relative to the loads the remaining pieces would have sustained if they had been rigged without the piece that failed. In other words, if fewer pieces have to share the same load, they will certainly experience higher loads. It is only the increment beyond these higher loads, if there is one, that is the subject of the extension question.
I don't think the extension problem is significant for a second falling on the anchor, unless they are practically at the anchor when they fall. The tests done by Jim Ewing of Sterling Ropes confirm this in a far more severe way with factor-2 falls from a drop tower. If you have a fair amount of rope in the system and anchor extension causes an additional drop that is small in relation to the amount of rope in the system, then there is little increment in load beyond what you'd expect if only the remaining pieces had been rigged to begin with.
The real question about belay anchors, or perhaps I should say the ultimate question, is how they will behave if there is a factor-2 fall of the leader directly onto the belayer (either because there was no pro between leader and belay or because whatever pro there was pulled). This is a very severe situation that occurs very infrequently. In the U.S., my impression is that approximately once every ten years or so such a scenario destroys the belay anchor, killing the entire party.
The problem in this scenario is that the belayer may be pulled off too if the rigging extends, and while the entire length of climbing rope between belayer and leader is involved in absorbing the leader's fall energy, the only thing that absorbs the belayer's fall energy is the tie-in from belayer to anchor. This is why tying the belayer in with slings is a bad idea; the slings can develop much higher tensions than the climbing rope when absorbing fall energy. This is not only bad for the anchors, it is also bad for the belayer.
Assuming the belayer has (sensibly) been tied to the anchor with the climbing rope, the tension in the tie-in strand is roughly determined by the ratio of rigging extension to tie-in length. For a given amount of rigging extension, the longer the tie-in, the lower the portion load on the anchor imposed by stopping the belayer's drop. Conversely, if a piece fails, it could be dangerous to have the belayer tied in very short to a rigging system that can extend, and one might go so far as to say that if a very short tie-in is required, than rigging that can extend is contraindicated.
Perhaps all this raises the question of why use rigging that can extend. The answer, but unfortunately it seems to be primarily a theoretical answer, is equalization. Potentially extendible webbing is the only way to get equalization of load---in theory---for most anchor configurations. It is certainly the only rigging that can adjust for direction of load. Sadly, the few tests I know about to date suggest that friction in the extending system seriously interferes with the theoretical equalizing properties of such systems, so that results may be no better than rigging with fixed arms that cannot extend. The one thing that has seemed to work reasonably well is the equalette on two anchor points. I don't know of any extending system that has been tested and has been shown to come close to equalization when three or more anchor points are involved.
Sorry for rambling on here (if indeed there is anyone left still reading).
Part of the problem with these discussions is that shock-loading is an undefined term. Part of the problem with it being undefined is that the term has acquired a negative sense: shock loading has to be bad.
It would be better if the term was simply banished from the discussion. The question is what happens when extendible anchor rigging (equalette, ACR, sliding X, Trango Alpine Equalizer) extends under a load that causes the failure of a piece. The "what happens" has to be evaluated relative to the loads the remaining pieces would have sustained if they had been rigged without the piece that failed. In other words, if fewer pieces have to share the same load, they will certainly experience higher loads. It is only the increment beyond these higher loads, if there is one, that is the subject of the extension question.
I don't think the extension problem is significant for a second falling on the anchor, unless they are practically at the anchor when they fall. The tests done by Jim Ewing of Sterling Ropes confirm this in a far more severe way with factor-2 falls from a drop tower. If you have a fair amount of rope in the system and anchor extension causes an additional drop that is small in relation to the amount of rope in the system, then there is little increment in load beyond what you'd expect if only the remaining pieces had been rigged to begin with.
The real question about belay anchors, or perhaps I should say the ultimate question, is how they will behave if there is a factor-2 fall of the leader directly onto the belayer (either because there was no pro between leader and belay or because whatever pro there was pulled). This is a very severe situation that occurs very infrequently. In the U.S., my impression is that approximately once every ten years or so such a scenario destroys the belay anchor, killing the entire party.
The problem in this scenario is that the belayer may be pulled off too if the rigging extends, and while the entire length of climbing rope between belayer and leader is involved in absorbing the leader's fall energy, the only thing that absorbs the belayer's fall energy is the tie-in from belayer to anchor. This is why tying the belayer in with slings is a bad idea; the slings can develop much higher tensions than the climbing rope when absorbing fall energy. This is not only bad for the anchors, it is also bad for the belayer.
Assuming the belayer has (sensibly) been tied to the anchor with the climbing rope, the tension in the tie-in strand is roughly determined by the ratio of rigging extension to tie-in length. For a given amount of rigging extension, the longer the tie-in, the lower the portion load on the anchor imposed by stopping the belayer's drop. Conversely, if a piece fails, it could be dangerous to have the belayer tied in very short to a rigging system that can extend, and one might go so far as to say that if a very short tie-in is required, than rigging that can extend is contraindicated.
Perhaps all this raises the question of why use rigging that can extend. The answer, but unfortunately it seems to be primarily a theoretical answer, is equalization. Potentially extendible webbing is the only way to get equalization of load---in theory---for most anchor configurations. It is certainly the only rigging that can adjust for direction of load. Sadly, the few tests I know about to date suggest that friction in the extending system seriously interferes with the theoretical equalizing properties of such systems, so that results may be no better than rigging with fixed arms that cannot extend. The one thing that has seemed to work reasonably well is the equalette on two anchor points. I don't know of any extending system that has been tested and has been shown to come close to equalization when three or more anchor points are involved.
Sorry for rambling on here (if indeed there is anyone left still reading).
In reply to Simon Wells:
Hi Simon,
climbing unrelated. Baby induced lack of kip is a situation I'm used to.
Teething child, sod the bonjela, Anbesol and Ashtons and Parsons powder. Did us a treat when we travelled around Europe with our daughter Daisy at 6 months old.
Also, singing 2 little boys and patience did me good through the night. In about a years time it will all be gone as by then, they will have grown up a lot more and you will actually miss those sleep depraved nights when you had the chance to cuddle them and all they did was look to you to help them from feeling sore.
Soz mate, may be a wee bit sentimental all that but it takes me back and I weirdly miss it. Cherish the moment however much sleep you have or haven't had, they will soon be grown up.
Hi Simon,
climbing unrelated. Baby induced lack of kip is a situation I'm used to.
Teething child, sod the bonjela, Anbesol and Ashtons and Parsons powder. Did us a treat when we travelled around Europe with our daughter Daisy at 6 months old.
Also, singing 2 little boys and patience did me good through the night. In about a years time it will all be gone as by then, they will have grown up a lot more and you will actually miss those sleep depraved nights when you had the chance to cuddle them and all they did was look to you to help them from feeling sore.
Soz mate, may be a wee bit sentimental all that but it takes me back and I weirdly miss it. Cherish the moment however much sleep you have or haven't had, they will soon be grown up.
In reply to Simon Wells: In a typical fall with over a few meters of rope out the couple of foot of dynamic rope to the anchors is only going to make a marginal difference think of it in terms of fall factors. What's more dynamic rope can actually cause problems as different lengths of dynamic rope to each anchor will stretch different amounts under the same load causing one of the anchors to take the majority of the load. There's been a tonne of experiments regarding this sort of stuff with results published on the net.
In reply to Denni: Or read them youtube.com/watch?v=CseO1XRYs9I&
In reply to rgold:
>The tests done by Jim Ewing of Sterling Ropes...
...weren't done with a hanging belayer, they were performed more as if a direct-anchor setup was being used. I think it was agreed above that shock-loading doesn't come from the seconder, it comes from the belayer effectively falling the extension distance onto static cord/webbing. Perhaps it should be counselled that a direct belay (with a munter hitch or such) should be used when performing a hanging belay on a system that may extend - the force absorption by a belayer above the climber is probably not as significant as the counter-weight effect of a belayer below the climber.
I also second the Samuel Jackson bedtime story for the teething.
>The tests done by Jim Ewing of Sterling Ropes...
...weren't done with a hanging belayer, they were performed more as if a direct-anchor setup was being used. I think it was agreed above that shock-loading doesn't come from the seconder, it comes from the belayer effectively falling the extension distance onto static cord/webbing. Perhaps it should be counselled that a direct belay (with a munter hitch or such) should be used when performing a hanging belay on a system that may extend - the force absorption by a belayer above the climber is probably not as significant as the counter-weight effect of a belayer below the climber.
I also second the Samuel Jackson bedtime story for the teething.
In reply to DeShark:
Thanks for all the advice of 'wee beasties dental problems'. We had the night from hell.....
My earlier posts are probably too vague and rambling.
1) Gear to rock interface is probably always the weak link in a belay
2) Shock loading (dam I used the forbidden word) increases the risk of that failure
3) Dynamic rope WITHIN the belay system will have a marginal affect on reducing the amount of sudden loading on the gear (not talking about rope from belay device to climber)
4) The more marginal the gear the more this becomes a problem, ie sudden load onto a 4ft girth oak tree....who cares...onto an RP1!!!!!!!
As a general rule it is potentially dangerous to slavishly follow a single system, ie I always use.....
Rather have a full took box. So I might use a cordallete on a multipitch route with reasonable gear that I am leading in a bloc, as the cordallete is simple, can be used as sling and I need to carry some abseil tat, so why cut up a sling. On two poor ice screws I would use my dynamic rope, in fact thinking about it when climbing with peers I virtually always use the rope, with clients the rope, only when I need to speed things up do I use a cordallete.
Each situation is different and it is possible to come up with a scenario that 'fits' an answer we already have. I often find that in climbing there are 6 solutions to everything, three are contrived and overly complex, two are adequate and the 6th in my eyes is the best compromise. Change one factor slightly and the range of answers change.
My students / client learn the first answer to any question I am asked is:
"It depends...."
So I would never say, never use a Equalette or always use one, but for me to date I have not felt it has enough flexibility to get a space on my crowded rack. Maybe if it was more shiny....
Thanks for all the advice of 'wee beasties dental problems'. We had the night from hell.....
My earlier posts are probably too vague and rambling.
1) Gear to rock interface is probably always the weak link in a belay
2) Shock loading (dam I used the forbidden word) increases the risk of that failure
3) Dynamic rope WITHIN the belay system will have a marginal affect on reducing the amount of sudden loading on the gear (not talking about rope from belay device to climber)
4) The more marginal the gear the more this becomes a problem, ie sudden load onto a 4ft girth oak tree....who cares...onto an RP1!!!!!!!
As a general rule it is potentially dangerous to slavishly follow a single system, ie I always use.....
Rather have a full took box. So I might use a cordallete on a multipitch route with reasonable gear that I am leading in a bloc, as the cordallete is simple, can be used as sling and I need to carry some abseil tat, so why cut up a sling. On two poor ice screws I would use my dynamic rope, in fact thinking about it when climbing with peers I virtually always use the rope, with clients the rope, only when I need to speed things up do I use a cordallete.
Each situation is different and it is possible to come up with a scenario that 'fits' an answer we already have. I often find that in climbing there are 6 solutions to everything, three are contrived and overly complex, two are adequate and the 6th in my eyes is the best compromise. Change one factor slightly and the range of answers change.
My students / client learn the first answer to any question I am asked is:
"It depends...."
So I would never say, never use a Equalette or always use one, but for me to date I have not felt it has enough flexibility to get a space on my crowded rack. Maybe if it was more shiny....
In reply to TobyA:
I wept with laughter Toby!
Its good to hear others struggle as I often worry we are living on the set of "Stepford Mothers". The local parent mafia all say their little ones sleep through from 7 to 7. Lying bastards!
I wept with laughter Toby!
Its good to hear others struggle as I often worry we are living on the set of "Stepford Mothers". The local parent mafia all say their little ones sleep through from 7 to 7. Lying bastards!
Simon,
Yes, as modern gear is so strong.
Well yes, but as been pointed out the increase in force is slight. This makes the real question: which is the best way to rig an anchor: risk a very small increase in force on a remaining arm, or try to equalise the force so an arm doesn't fail by using a sliding system? I guess the answer is sometimes the former, sometimes the latter.
Is this true? I know the length of rope is small, but if might add to several meters, and importantly if contains knots. (Anyone remember some test data that was doing the rounds on the energy absorbed in knots in sports falls?)
Exactly, so the question is do you try and equalise a bunch of rp's with a sliding system to try and share the forces (at the risk of extension) or use a "static" i.e. non-moving system such as the rope or a big sling with an overhand?
One question that is not addressed enough is that when using systems with fixed arms (e.g. the rope) there is a tendency to set the thing in an arrangement for supporting the leader as she hangs at the belay. The real test will either come from the second failing off or the leader falling on the next pitch. The direction of pull from the second will change as gear is removed from the route, especially the last piece. The direction of pull when the leader falls will be onto the belay if they fall before placing the first piece, in the direction of the first piece, or possibly the direction of the second piece later if she is using two ropes. This means knowing the place she will place the first bit of gear in both ropes when you set the belay. No chance.
The direction of pull changes so much between these situations that the failure of any one arm will for some situations lead to a "shock" load on the remaining. (Example, three cams in a triangle, leader falls, lowest cam rips (because it is the one that takes the force, and was set nice and low so it could), the belayer flies up and "shock loads" the upper cams.) This shows that using the rope (or other system) does not solve the problem of extension. Belay failure is (as was pointed out by another poster) mainly an issue when the leader falls off, not when the second does.
The way I think about it is to reflect on the difference between extension that might do something positive (e.g. sliding-x's on bunches of rp's) and extension that does nothing but (slightly) increase the force on the rest of the belay when an arm fails, or usually more important, swings the belayer into something (or over the edge) and makes them let go of the rope!
Sorry for the length of that. I hope it seems at last half clear.
PS. The book: the contented baby, worked wonders for us. But I know the book is considered more controversial than chipping gritstone.
> 1) Gear to rock interface is probably always the weak link in a belay
Yes, as modern gear is so strong.
> 2) Shock loading (dam I used the forbidden word) increases the risk of that failure
Well yes, but as been pointed out the increase in force is slight. This makes the real question: which is the best way to rig an anchor: risk a very small increase in force on a remaining arm, or try to equalise the force so an arm doesn't fail by using a sliding system? I guess the answer is sometimes the former, sometimes the latter.
> 3) Dynamic rope WITHIN the belay system will have a marginal affect on reducing the amount of sudden loading on the gear (not talking about rope from belay device to climber)
Is this true? I know the length of rope is small, but if might add to several meters, and importantly if contains knots. (Anyone remember some test data that was doing the rounds on the energy absorbed in knots in sports falls?)
> 4) The more marginal the gear the more this becomes a problem, ie sudden load onto a 4ft girth oak tree....who cares...onto an RP1!!!!!!!
Exactly, so the question is do you try and equalise a bunch of rp's with a sliding system to try and share the forces (at the risk of extension) or use a "static" i.e. non-moving system such as the rope or a big sling with an overhand?
One question that is not addressed enough is that when using systems with fixed arms (e.g. the rope) there is a tendency to set the thing in an arrangement for supporting the leader as she hangs at the belay. The real test will either come from the second failing off or the leader falling on the next pitch. The direction of pull from the second will change as gear is removed from the route, especially the last piece. The direction of pull when the leader falls will be onto the belay if they fall before placing the first piece, in the direction of the first piece, or possibly the direction of the second piece later if she is using two ropes. This means knowing the place she will place the first bit of gear in both ropes when you set the belay. No chance.
The direction of pull changes so much between these situations that the failure of any one arm will for some situations lead to a "shock" load on the remaining. (Example, three cams in a triangle, leader falls, lowest cam rips (because it is the one that takes the force, and was set nice and low so it could), the belayer flies up and "shock loads" the upper cams.) This shows that using the rope (or other system) does not solve the problem of extension. Belay failure is (as was pointed out by another poster) mainly an issue when the leader falls off, not when the second does.
The way I think about it is to reflect on the difference between extension that might do something positive (e.g. sliding-x's on bunches of rp's) and extension that does nothing but (slightly) increase the force on the rest of the belay when an arm fails, or usually more important, swings the belayer into something (or over the edge) and makes them let go of the rope!
Sorry for the length of that. I hope it seems at last half clear.
PS. The book: the contented baby, worked wonders for us. But I know the book is considered more controversial than chipping gritstone.
In reply to DeShark: I've made an ACR and used it a fair bit. Quite reassuring for riskier belays where you want to keep the rope running freely. You can tie the arms off to limit extension (or if the cord gets cut in most places). My biggest problem was that it is a big and ungainly bit of tat that's not much use for anything else.
In reply to David Coley:
Mmmmm, we seem to agree on the concepts but disagree on the soloution!
My personal opinion is to set up the belay at the right place (ABC) to avoid the need for a self eqaulising system. Which means you avoid the possible shock loading of a piece of gear if the Eqaulette fails. To my simple mind the Eqaulette solves one problem but creates more.
You have an excellent point about re-directing belays for lead V second. The other one I see a lot is not re-orienteering the belay device when a person leads through, making the belayer the lead climbers first runner!!!
PS The Contented Baby? We have gone done the Seers / Attatchment parenting route, much to the horror of my Mother, sister and several other female relatives. We had a much better night last night so I guess its swings and round abouts!
Mmmmm, we seem to agree on the concepts but disagree on the soloution!
My personal opinion is to set up the belay at the right place (ABC) to avoid the need for a self eqaulising system. Which means you avoid the possible shock loading of a piece of gear if the Eqaulette fails. To my simple mind the Eqaulette solves one problem but creates more.
You have an excellent point about re-directing belays for lead V second. The other one I see a lot is not re-orienteering the belay device when a person leads through, making the belayer the lead climbers first runner!!!
PS The Contented Baby? We have gone done the Seers / Attatchment parenting route, much to the horror of my Mother, sister and several other female relatives. We had a much better night last night so I guess its swings and round abouts!
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