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Not meaning to open a can of worms - cross loading carabiners

tailgunner said:
This is never brought up when talking about the aluminium sticks or platforms that are not desighned by engineers though .
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If your aluminum stick breaks and you fall, then you're not climbing safely to begin with. I am concerned with single points of failure that can lead to a fall. I get around any concerns by using a tether and lineman's while climbing and then set up my lineman's as a secondary, slack tether attached to my saddle belt.
 
WLL is a gigantic safety margin built in to account for standard use and age. Theoretically, the more you use PPE, the chance the break limit will be slightly reduced over time. But it's also there in ropes to account for knots in the rope.

The best thing to do is check the various standards the carabiner you like is tested to. If the criteria includes cycle to failure, you will have your answer. To my knowledge, no standard tests this. Just mbs across various areas of the carabiner. Bike components probably aren't tested to the extent carabiners are

Single points of failure will always exist in some capacity. Ex: You can use a backup line, but you're still on the same harness.
 
TreeRecon said:
WLL is a gigantic safety margin built in to account for standard use and age. Theoretically, the more you use PPE, the chance the break limit will be slightly reduced over time. But it's also there in ropes to account for knots in the rope.

The best thing to do is check the various standards the carabiner you like is tested to. If the criteria includes cycle to failure, you will have your answer. To my knowledge, no standard tests this. Just mbs across various areas of the carabiner. Bike components probably aren't tested to the extent carabiners are

Single points of failure will always exist in some capacity. Ex: You can use a backup line, but you're still on the same harness.
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With all due respect, you aren't addressing the point.
 
raisins said:
With all due respect, you aren't addressing the point.
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I'm not sure why the bike components are failing. But I can tell you "cycles to failure" is not even a measured metric across in any "at height" industry.

This is DMM: Currently the most popular arb carabiner manufacturer. Not sure where they source their aluminum, but I would bet their manufacturing process is more tightly controlled then bicycle components

 
TreeRecon said:
I'm not sure why the bike components are failing. But I can tell you "cycles to failure" is not even a measured metric across in any "at height" industry.

This is DMM: Currently the most popular arb carabiner manufacturer. Not sure where they source their aluminum, but I would bet their manufacturing process is more tightly controlled then bicycle components

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Maybe the 'biner makers are just wrong not to be concerned? Maybe they don't think climbers are going to be sitting and shifting on aluminum all the time while climbing? Maybe a lot of us are using climbing gear in ways that rock climbers do not?

I don't want to beat a dead horse even more, so I'll stop. But I'll just keep doing what I do now which is to back everything up and change out all my 'biners every few years. They are cheap enough that replacing my 3 aluminum 'biners is about like a steak dinner in price. So, I'll just keep doing that so that I feel safe.

edit: one more link I'm reading specifically about carabiner fatigue failure

 
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Nothing puts more force on a carabiner than a dynamic event. I'm referring to a fall factor 2. They are well aware of the forces the carabiners are subjected to during this. As saddle hunters, we should be much more focused on the health of the tree
 
Fatigue of metal is all about cumulative damage that occurs from stress levels that happens during each subsequent loading. The severity of those loadings determines how much stress is applied. Metals with an endurance limit exhibit a minimum stress level below which no damage occurs and essentially will not fatigue due to repeated stresses under that limit (most steels). This is shown by how the blue line levels off in the graph below once a minimum stress level is reached.

Metals that don't exhibit an endurance limit will continue to see cumulative damage (fatigue) due to cyclic loadings. However, the extent of each loading's damage is a direct function of how severe the load is. In the case of a typical 22kN (~4950lbs) rated carabiner the stresses applied under loads of 300lbs (1.4kN) loads are so low that there is essentially no damage with each loading putting us way out of the right hand side of the red curve shown below.

In the case of aluminum bicycle components the applied stress levels are likely a much higher percentage of the failure stress resulting in more cumulative damage per load and therefore shorter life expectancy (left side of the red curve). This is because in the case of bicycle components (and also climbing sticks lately) the push to reduce weight means that thinner walled materials are being used. Since stress is effectively the applied load divided by the material thickness, thinner material means higher stresses from the same load applications. In a nutshell, generally speaking the price for lighter weight is a reduction in cycles to failure.

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boyne bowhunter said:
Fatigue of metal is all about cumulative damage that occurs from stress level that happens during each subsequent loading. The severity of those loadings determines how much stress is applied. Metals with an endurance limit exhibit a minimum stress level below which no damage occurs and essentially will not fatigue due to repeated stresses under that limit (most steels). This is shown by how the blue line levels off in he graph below once a minimum stress level is reached.

Metals that don't exhibit an endurance limit will continue to see cumulative damage (fatigue) due to cyclic loadings. However, the extent of each loading's damage is a direct function of how severe the load is. In the case of a typical 22kN (~4950lbs) rated carabiner the stresses applied under loads of 300lbs (1.4kN) loads are so low that there is essentially no damage with each loading putting us way out of the right hand side of the red curve shown below.

In the case of aluminum bicycle components the applied stress levels are likely a much higher percentage of the failure stress resulting in more cumulative damage per load and therefore shorter life expectancy (left side of the red curve). This is because in the case of bicycle components (and also climbing sticks lately) the push to reduce weight means that thinner walled materials are being used. Since stress is effectively the applied load divided by the material thickness, thinner material means higher stresses from the same load applications. In a nutshell, generally speaking the price for lighter weight is a reduction in cycles to failure.

View attachment 101691
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Y-axis is kilopounds per square inch?

If so, I'm guessing this is a general curve and any specific aluminum piece would have it's own curve (?). If so, is there a way to convert this curve into a carabiner-specific one to get an idea of how many cycles they can withstand? Seems like carabiner area contacting the rope and also the depth of the carabiner would come into play here. I'm just gonna keep trading out 'biners whenever I feel like it. I don't think it makes sense to stand on a $500 platform while trying to save a bit by using 10 year old 'biners.
 
raisins said:
Y-axis is kilopounds per square inch?

If so, I'm guessing this is a general curve and any specific aluminum piece would have it's own curve (?). If so, is there a way to convert this curve into a carabiner-specific one to get an idea of how many cycles they can withstand? Seems like carabiner area contacting the rope and also the depth of the carabiner would come into play here. I'm just gonna keep trading out 'biners whenever I feel like it. I don't think it makes sense to stand on a $500 platform while trying to save a bit by using 10 year old 'biners.
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Yes, Y axis is kilopounds/sq in. The presented curves are generalized. For specific materials the curves vary by both material composition and heat treat (hardness/maximum allowable stress) and are developed by testing actual materials using known cross-sections and loads to failure. If you look at the X axis of this generalized curve for the aluminum you'll note that at approximately 50% of the stress level represented that it would take to break quickly it would take an equivalent 10e6 cycles to break. That's a million cycles at roughly repeating loads of 1/2 the maximum stress, let's call that 11kN (2475 lbs) for a 22kN rated carabiner, since the cross-sectional area isn't changing. Work your way out to 10% of that rated load or 2.2kN (495 lbs) and you're well over a billion cycles to failure. Probably not something you need to worry about in our usage.

Now I will point out failure is a summary of cumulative loading so if you have a couple high load events combined with a lot of lower load cycles you could see earlier failures. This is why manufacturer's recommend retiring equipment that has seen significant load events.
 
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If you're using rated equipment, as intended, your anchorage point is where the focus should be in climbing.
 
brydan said:
I hear ya, I'm a retired Arborist myself. The good thing is that safety and using quality gear climbing is mainstream now, that wasn't always the case in the SH community to put it mildly. My personal opinion is that non-climbers have never seen or experienced a climbing accident happen before so they tend to picture equipment failure as likely source of an accident. For those of us that have had a mishap or seen it happen it's almost never equipment failure, it's almost always user error of one form or another.
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When I worked in the climbing industry, we thought you tree climbers/arborists were crazy. Sort of like the cave explorers. Back then, and it’s been over 30 years, I saw some tree climbers do some sketchy stuff. Glad it’s definitely gotten better.
 
raisins said:
Maybe the 'biner makers are just wrong not to be concerned? Maybe they don't think climbers are going to be sitting and shifting on aluminum all the time while climbing? Maybe a lot of us are using climbing gear in ways that rock climbers do not?

I don't want to beat a dead horse even more, so I'll stop. But I'll just keep doing what I do now which is to back everything up and change out all my 'biners every few years. They are cheap enough that replacing my 3 aluminum 'biners is about like a steak dinner in price. So, I'll just keep doing that so that I feel safe.

edit: one more link I'm reading specifically about carabiner fatigue failure

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I think you’re being majorly short sighted of the overall climbing community if you are just thinking of just rock climbers. The overall community, and therefore the overall major design parameters encompass traditional and big wall climbers who would certainly come into the same amount of “cycles” that we do, as well as mountaineering, ice climbers, canyoneering (who also tax their equipment considerably as they put lots of weight and use on it) as well as other forms.

You honestly are creating a concern that is addressed in the manufacturing of the said equipment. Their intended audience abuses the equipment so much more than we ever will and it is designed for that.
 
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CharlieTN said:
I think you’re being majorly short sighted of the overall climbing community if you are just thinking of your rock climbers. The overall community, and therefore the overall major design parameters encompass traditional and big wall climbers who would certainly come into the same amount of “cycles” that we do, as well as mountaineering, ice climbers, canyoneering (who also tax their equipment considerably as they put lots of weight and use on it) as well as other forms.

You honestly are creating a concern that is addressed in the manufacturing of the said equipment. Their intended audience abuses the equipment so much more than we ever will and it is designed for that.
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1. look up definition of term "maybe" that i purposefully used, asking questions (even in a roundabout way) is the opposite of short-sighted

2. it is unwise to say "those experts that take my money are so smart that I should trust them totally and implicitly".....I've been disappointed by a ton of supposed experts and so has everyone else....for instance, I'm sitting here successfully rehabing an old injury because the root cause and how to fix it was not caught by a specialist MD nor the two different PTs that I was sent to.....but me and google figured it out finally
 
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raisins said:
1. look up definition of term "maybe" that i purposefully used, asking questions (even in a roundabout way) is the opposite of short-sighted

2. it is unwise to say "those experts that take my money are so smart that I should trust them totally and implicitly".....I've been disappointed by a ton of supposed experts and so has everyone else....for instance, I'm sitting here successfully rehabing an old injury because the root cause and how to fix it was not caught by a specialist MD nor the two different PTs that I was sent to.....but me and google figured it out finally
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But your example in your question was short sighted because you were suggesting that perhaps we as saddle hunters actually put more stress on the equipment, specifically aluminum carabiners, than a singular segment of climbing, not taking into account how much abuse those carabiners actually go through by everyone who uses them. The manufacturers of this equipment have been doing it a very long time and they design that equipment for those extreme abuses. They cannot afford the lawsuits that would ensue if they didn’t.

As noted before, most accidents that happen do so due to human error, more than any equipment failure and that is because the industry is so overly cautious. When there are equipment failures it is almost always due to either severe abuse, or being used outside of the intended specs. While you could argue we are using this equipment outside of the intended design, we are nowhere near the safety specs the equipment is designed to handle. Now if you were to let out your rappel rope, fasten into the very end of it and then jump out of the tree to take a whipper down to the bottom, then you would probably be getting close to the limits of any and all of our climbing rated equipment. The truth is though, your body would assuredly break before any of the equipment would. I’ve been to the PMI rope manufacturing plant and have seen how they test the ropes. I’ve worked with reps from Petzl and Black Diamond and have seen how that equipment is tested. This is why we tell people over and over again to stick with the major brands and avoid the chines made Amazon stuff. You know what you’re getting that way.

Now, to back this conversation up a bit, I am more suspect of the ratings given to climbing sticks, stands, and platforms than I ever would be any of the climbing gear from those manufacturers. Look at where failures and accidents are happening. Steps breaking or bending is one of the most common, although still not that common. Platforms buckling, or sticks kicking out. In each of these, there is no failure of industry standard rated climbing equipment, it is of the hunting industry specific equipment which does not hold as high of standards.
 
CharlieTN said:
But your example in your question was short sighted because you were suggesting that perhaps we as saddle hunters actually put more stress on the equipment, specifically aluminum carabiners, than a singular segment of climbing, not taking into account how much abuse those carabiners actually go through by everyone who uses them. The manufacturers of this equipment have been doing it a very long time and they design that equipment for those extreme abuses. They cannot afford the lawsuits that would ensue if they didn’t.

As noted before, most accidents that happen do so due to human error, more than any equipment failure and that is because the industry is so overly cautious. When there are equipment failures it is almost always due to either severe abuse, or being used outside of the intended specs. While you could argue we are using this equipment outside of the intended design, we are nowhere near the safety specs the equipment is designed to handle. Now if you were to let out your rappel rope, fasten into the very end of it and then jump out of the tree to take a whipper down to the bottom, then you would probably be getting close to the limits of any and all of our climbing rated equipment. The truth is though, your body would assuredly break before any of the equipment would. I’ve been to the PMI rope manufacturing plant and have seen how they test the ropes. I’ve worked with reps from Petzl and Black Diamond and have seen how that equipment is tested. This is why we tell people over and over again to stick with the major brands and avoid the chines made Amazon stuff. You know what you’re getting that way.

Now, to back this conversation up a bit, I am more suspect of the ratings given to climbing sticks, stands, and platforms than I ever would be any of the climbing gear from those manufacturers. Look at where failures and accidents are happening. Steps breaking or bending is one of the most common, although still not that common. Platforms buckling, or sticks kicking out. In each of these, there is no failure of industry standard rated climbing equipment, it is of the hunting industry specific equipment which does not hold as high of standards.
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I wasn't suggesting anything. You projected what you thought I meant onto me and are even now saying "no, you're wrong in what you wrote and your own intentions." You honestly think asking a an honest question is suggesting something? Serious question, do you have ESPN?

I was asking questions that pointed to things that perhaps weren't addressed in other's responses to me.

You don't seem to realize that someone can simultaneously be right and also make a bad argument, which you are doing. But most of us can't take an L in public (in this case, even though you might be right subject matter wise, you should just admit that you are wrong in your approach, but most people can't do that). The correct response might be "oh, you're right, I see now that you were asking questions, sorry." But nope.

Not in the mood today, bye.
 
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