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majid_sabet
Aug 22, 2007, 5:01 AM
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Trentw wrote: Thanks Trenchdigger for a well thought out reply. In reply to: Trentw wrote: 3. Shock loading of two biners causes them to be severely weakened (testing?) Where'd you read this? Most slings are made of spectra and stretch very little. On top of that, carabiners and slings are just one link in the safety system. The rope is your main shock absorber. Switching out a sling with a carabiner will make virtually no difference in the shock load in a climbing situation. I can't remember where I read this. Thats why I'm trying to confirm or deny it now. Swede brings up a point about the small surface area clashing together with biner to biner, and could be cause for concern. This does not happen with sling to biner. This shock loading problem may not be a big issue, due to the millions of tests done every year on the cliffs with biners in hangers, and no reported failures (to my limited knowlegde). Trent.
start from here, I will get you more
http://www.uiaa.ch/...N12275Connectors.pdf
(This post was edited by majid_sabet on Aug 22, 2007, 5:02 AM)
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trenchdigger
Aug 22, 2007, 5:06 AM
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Trentw wrote: Swede brings up a point about the small surface area clashing together with biner to biner, and could be cause for concern. This does not happen with sling to biner.
True, however, with a little knowledge about the materials involved, you realize that this is not of concern. If the pressure becomes too great in the small area where the carabiners are in contact, the metal will just deform locally (ie. dent). I believe the procedure for pull-testing carabiners involves stretching them between metal pins of a standard diameter (I don't remember off-hand what that dia. is). I believe Omega Pacific pulls all of their carabiners to a certain (significant) percentage of their rated strength with this method. If you look at their carabiners, you'll see a little dent at either end where the rope would rest - that's from the metal pin during the pull test. Something similar would result in a significant loading of a carabiner clipped to a carabiner.
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greenketch
Aug 22, 2007, 5:19 AM
Post #53 of 72
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Trentw wrote: 1. They unclip easier, compared to using a sling 2. The BD carabiner instructions doesn't warn against it 3. Shock loading of two biners causes them to be severely weakened (testing?) 4. Clipping more then two biners into another biner can cause triaxial loading 5. Triaxial loading can serverly weaken the biner (testing?) 6. The BD carabiner instructions warn against triaxial loading
To the best I can support or deny your questions here are some answers
(1) What can be done at home in practice is only partially supportive of on the rock. Two loose biners have been observed to unclip from each other as the rope or sling tugs them in differant direction. this usually happens when transitioning from loaded to unloaded states. It is normal an acceptable to clip biner to biner in aid climbing and when the load will be constant and predictable.
(2)BD only instructs on expected uses of a biner. It would be silly of them to add warnings against everything that can be done. Since there are known methods and uses of going biner to biner they can't really say don't.
(3) Shock loading weakening the biners is not likely. Even the 100% spectra cordage that is made. (I use it as a rigger but it is not in climbing use) has more dynamic qualities than a cable. There are several rigging texts that catalog this. It is also confirmed by any aid climber that has tried to use a funkness made with a sling it is cable or nothing. In the use in question I would suggest that a fall on several biners in a chain would be a brutal catch. One may even break a biner but nobody has ever tried it I know of.
(4) This is very likley the case. Why do you think that companies produce rigging plates to conect more than two biners to. I do not know of any tests but cannot concieve of a situation where the pulls would be oriented for all three biners to have correct loading.
(5) There are numerous test that confirm triaxial loading. Let alone the math of force mutliplication. Look at the certified rating stamped on your biner. these are established by both manufacture and third party tests. On axis is very differant from off axis which is diferant from open gate. How would you propose loading in more than one direction and not varying from the one known strong orientation?
(6)I don't see any question there. What is your point?
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curt
Aug 22, 2007, 6:02 AM
Post #54 of 72
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Trentw wrote: ...Thanks for your time, but I would prefer an explanation as to why you beleive this. I'm am not after rules of thumb, or a vote for the best method. If I did I would've posted in the beginners forum. Trent.
Which is exactly where dumb-assed questions like yours belong, n00b
Curt
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rocknice2
Aug 22, 2007, 6:24 AM
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Trentw wrote: 1. They unclip easier, compared to using a sling 2. The BD carabiner instructions doesn't warn against it 3. Shock loading of two biners causes them to be severely weakened (testing?) 4. Clipping more then two biners into another biner can cause triaxial loading 5. Triaxial loading can severely weaken the biner (testing?) 6. The BD carabiner instructions warn against triaxial loading Trent.
1. They unclip easier, compared to using a sling
Depends on how your using them. The problem is more than just unclipping, it also includes a twisting load. As a biner is twisted it rides up on the other biner until a part of it is up against the gate. Then it unclips.
On lead if going straight up a combination of biners that lets the bottom biner sit parallel to the wall will not cause biner twist. This will require an odd # 3,5,7.... of biners on a bolt. On a traverse a perpendicular to wall bottom biner is desirable. Even # 2,4,6.. of biners.
A sling relieves much of these problems.
2. The BD carabiner instructions doesn't warn against it
Black Diamond wrote: -Warning: In certain situations a carabiner gate can open accidentally. Rock protrusions can open a cara-biner gate, whiplash from a sudden impact can cause gate opening, and wear and tear can cause a gate to stick open. -Open carabiners pose a significant hazard to a climber because they are not as strong as when the gate is closed. -Try to envision how every carabiner you use will be affected in the event of a fall and place it accordingly. Think ahead. -Always read instructions and warnings that accompany your gear. -Seek qualified professional instruction.
3. Shock loading of two biners causes them to be severely weakened (testing?)
Severely loading of any biners causes them to be severely weakened.
4. Clipping more then two biners into another biner can cause triaxial loading
Yes if the two biners have loads pulling in different directions.
If pull is in the same direction it's lessened but still there, especially if top biner is asymmetrical [d-shaped]. This is because one biner is not up against the spine.
Ovals handle this example much better.
5. Triaxial loading can severely weaken the biner (testing?)
A biner is weaker under triaxial load.
Plenty of tests you do the search
6. The BD carabiner instructions warn against triaxial loading
Yes they do
Trentw wrote: Are there any other reasons why I should or shouldn't connect two carabiners together? Can anyone confirm any of the points above with studies and testing info?
You've been a real asshole. You gotten a lot of useful response but focused on the bad ones. Do your own research.
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Trentw
Aug 22, 2007, 7:45 AM
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In reply to: Which is exactly where dumb-assed questions like yours belong, n00b Curt
Oh hello Curt. Thanks for joining the thread with your presence of 11,000 posts. Tell me exactly why my questions are dump-assed?
Multiple searches on this topic didn't reveal much useful information. I did a little research, read through a few books, but didn't come up with any answers that satisfied my questions. Maybe you just can't answer my questions, thats fair enough, you don't need to get offensive about it. There are others here with some useful information.
Maybe you should put more thought into your posts, or not post at all?
All threads need direction, and I'm trying to keep this one going in the right one. My reply to Majid was courteous while informing him I would like more information and why.
Thanks for reading,
Trent.
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Trentw
Aug 22, 2007, 8:11 AM
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Hi Rocknice,
In reply to: Black diamond: -Try to envision how every carabiner you use will be affected in the event of a fall and place it accordingly. Think ahead.
Well, this is what I'm trying to find out with this thread. That point begs the question.
In reply to: 3. Shock loading of two biners causes them to be severely weakened (testing?) Severely loading of any biners causes them to be severely weakened.
Shock loading doesn't necessarily mean severe loading.
I like your points about off-set D's and ovals. I would like to find some tests on how significant the triaxial loading is thou. Still looking.
In reply to: You've been a real asshole. You gotten a lot of useful response but focused on the bad ones. Do your own research.
There happens to be a fair few 'bad' posts, and since I like to reply to all posts, it may seem like I'm only responding to the bad ones. If I don't reply to the fluff posts I'm afraid that more fluff will follow, so I need to direct the thread away from these useless posts.
"Do my own research"? I thought this was an open and sharing community. I'm sharing info here as much as asking for it. Who are you anyway to tell me what to do? A moderator? An aspiring 11,000+ poster?
Oh I'm an asshole eh? Yes I have been abrupt, but no need for name calling, just keep with the well thought out posts. Oh what the hell, name calling can be fun. Go be intimate with an animal you poo poo head.
Cheers,
Trent
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flint
Aug 22, 2007, 10:16 AM
Post #58 of 72
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poo poo head, really... come on.
just helping to fill your email with updates on the numberous, "useless" posts.
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curt
Aug 23, 2007, 3:23 AM
Post #59 of 72
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Trentw wrote: In reply to: Which is exactly where dumb-assed questions like yours belong, n00b Curt Oh hello Curt. Thanks for joining the thread with your presence of 11,000 posts. Tell me exactly why my questions are dump-assed? Multiple searches on this topic didn't reveal much useful information. I did a little research, read through a few books, but didn't come up with any answers that satisfied my questions. Maybe you just can't answer my questions, thats fair enough, you don't need to get offensive about it. There are others here with some useful information...
I could answer your question but this is very simple--and others have already done that adequately. The only reason for not clipping two carabiners together is a relatively minor concern: i.e. that they may become unclipped under some very specific circumstances. Interestingly, those circumstances are not under normal loading conditions, but rather when a rotational component is applied to the carabiners before they become fully weighted along their primary axis. It is relatively simple to set things up so that that can not occur.
Still, if you need a "black or white" recommendation, then it's probably best to always avoid clipping carabiners together--particularly if you have no idea what you are doing in the first place.
Curt
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stymingersfink
Aug 23, 2007, 4:27 AM
Post #60 of 72
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swede wrote: there are recommendations for always having the same carabiner in contact with the bolt-hanger (and the other one for the rope) and also for not using slings which are not wide enough. If this is due to tests/ real experiences or just a safety measure based on how to conduct safety work - I don´t know.
My reasoning for always clipping the pro with one biner and the rope with another (i use standard gates for pro, wiregates for rope) is to protect my rope. When gear is fallen upon, there are times when the inside of the protection biner will develop sharp edges. If I were to clip my rope with this biner sometime later in a climb, the possibility exists for the resulting sharp edges to do significant damage to my rope's sheath (or worse!). Since I try to treat my rope better than this, I avoid clipping it with a "protection" biner, preferring to clip it with my designated wiregates.
Wiregates, BTW, experience less gate flutter in some situations which have a high probability of occurring during a fall. They are, IMHO, a superior solution to the problem of attaching your rope through a piece of pro.
edit to add:
Curt,
Is it really fair to participate in a battle of wits with an un-armed man?
I guess he did bring that shit on himself though... too bad for him.
(This post was edited by stymingersfink on Aug 23, 2007, 5:26 AM)
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Trentw
Aug 23, 2007, 8:25 AM
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These are all the bits of info on triaxial loading so far:
In reply to: greenketch: (5) There are numerous test that confirm triaxial loading. Let alone the math of force mutliplication. Look at the certified rating stamped on your biner. these are established by both manufacture and third party tests. On axis is very differant from off axis which is diferant from open gate. How would you propose loading in more than one direction and not varying from the one known strong orientation?
In reply to: swede: Triaxial loading: Not good at all. People not used to mechanic calculations does not really understand how bad this can be. You will find threads dealing with the american death triangle with nice drawings. Please remember that most carabiners are built to take the load along the side with no gate.
In reply to: trenchdigger: It really depends on the orientation. On top of that if you try to stack too many carabiners in another single carabienr, you could conceivably end up with funky loading, but I wouldn't worry too much about this.
In reply to: rocknice2: Yes if the two biners have loads pulling in different directions. If pull is in the same direction it's lessened but still there, especially if top biner is asymmetrical [d-shaped]. This is because one biner is not up against the spine. Ovals handle this example much better.
Just to keep this simple, lets fix the overall force on a biner to a set amount. This rules out force multiplication coming into the biner. If we have a force going up and down the spine of an D shaped biner, this is normal loading. If we add another force to that at a different angle, say at 45 degrees to the gate, this biner is now under triaxial loading.
I'm a bit rusty on my mechanics, and not sure of how the aluminum they use in a carabiner performs so could someone please correct, with an explanation, if I'm wrong:
This carabiner will fail, not because of the triaxial loading in particular, but because the overall forces across the minor axis of the gate exceed its safety rating.
In other words, triaxial loading (assuming the total force into the carabiner is constant) is not important, but the amount of force across the minor axis is, which occurs more so when a carabiner is triaxially loaded.
Cheers,
Trent
Edit note: Fixed editing
(This post was edited by Trentw on Aug 23, 2007, 8:29 AM)
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Trentw
Aug 23, 2007, 8:26 AM
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In reply to: snowboardercolo: The same point can be raised would you climb on a biner or ATC that had taken a good fall with visual damage? How much is your life worth? How much is the life of the person you are climbing with worth?
In reply to: Trent: What has this got to do with anything? There has been no mention of biner damage. Whats my life worth got to do with anything? You seem to be presuposing that biner to biner is dangerous
In reply to: snowboardercolo: You asked the questions yet you are very rude to the people on the board. The whole discussion evolves around possible damage.
You were talking about your lifes worth which has nothing to do with this conversation. Let me explain: Obviously if we make the assumption that biner to biner is life threatening, and if you continued to use it in this way, one would then have to start questioning whether it was still worthwhile to do it; and bring up questions of life worth etc.
But there has been no assumption that biner to biner is life threatening. This discusion is looking at this exact point, with arguments for and against it, or more accurately how they work. Therefore your questions of life worth are not needed in this conversation.
I'm sorry if I come across rude. I may have mistaken this to be a technical forum, and it is really a social club for people to talk about how shinny their gear is, and how pretty they look in it. I'm nicer in a more social environment. I'm abrubt here, as this can be a pretty technical issue with many other points for confusion. I think people should lighten up a bit, and be a lot less sensitive.
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Trentw
Aug 23, 2007, 8:54 AM
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In reply to: Curt, Is it really fair to participate in a battle of wits with an un-armed man? I guess he did bring that shit on himself though... too bad for him
Yeah, he really got me with the n00b comment, it hurts. And he used the red colour! Omg, I don't know what I'll do.
But to be fair too Curt, he did come around and provide a little info on the subject at hand, instead of just flaming for no good reason.
But good for you stymingersfink and encouraging senseless conflict. I hope it works out well for you in life.  I think this thread, and forum in general, will be more useful to people if we stop discouraging questions by using derogatory terms like n00b and calling people assholes.
I don't really care too much, I've been climbing for a while, and take safety seriously, so I will keep on asking questions. I may on the other hand be a little more reluctant to share as much useful information.
There seems to be a general running attitude of dumbing down answers or even discouraging questions. Why? Don't people want to understand how their safety systems work? [end rant]
I'm off climbing, although only indoor (its pissing down here)
Trent.
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reg
Aug 23, 2007, 11:41 AM
Post #64 of 72
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stymingersfink wrote: My reasoning for always clipping the pro with one biner and the rope with another (i use standard gates for pro, wiregates for rope) is to protect my rope. When gear is fallen upon, there are times when the inside of the protection biner will develop sharp edges.
great point
(This post was edited by reg on Aug 23, 2007, 11:43 AM)
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reg
Aug 23, 2007, 11:58 AM
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Trentw wrote: In other words, triaxial loading (assuming the total force into the carabiner is constant) is not important, but the amount of force across the minor axis is, which occurs more so when a carabiner is triaxially loaded. Cheers, Trent Edit note: Fixed editing
triaxial loading is important - no matter if the total force onto the carabiner is constant or not - if the load exceeds any "off axsis" recomendations - you may die or worst. is that clear enough? trent - don't be a dick - only richard (me) can be a dick!
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swede
Aug 24, 2007, 7:18 AM
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reg wrote: Trentw wrote: In other words, triaxial loading (assuming the total force into the carabiner is constant) is not important, but the amount of force across the minor axis is, which occurs more so when a carabiner is triaxially loaded. Cheers, Trent Edit note: Fixed editing triaxial loading is important - no matter if the total force onto the carabiner is constant or not - if the load exceeds any "off axsis" recomendations - you may die or worst. is that clear enough? trent - don't be a dick - only richard (me) can be a dick!
My mechanics are also a bit rusty and I have to explain in a foreign language. Triaxial loading should theoretically still matter.
The minor axis thing is one part of the problem. Forces are vectors which mean that you can divide them "along axis" and "off-axis" and use the ratings printed on the carabiner.
The second part is that IF you have a large angle between the triaxial load AND the point most pointing away from the loading from the climber have to take up a large part of that force - there is going to be a very high loading at that carabiner (due to vectors). I know this is not good explained but if you are familiar with vector forces you should get it.
The third part is momentum. Most probably in the triaxial loading case you will have one carabiner close to the spine of the carabiner and the other one close to the nose/gate opening. This will mean a momentum arm increasing the loading at the spine (since movement will most probably occur at the weaker gate opening). Several pictures I have seen on failure due to triaxial loading show the carabiner broken/bent near the top of the spine, which must be due to momentum.
(This post was edited by swede on Aug 24, 2007, 10:53 AM)
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JTeastAZ
Jul 11, 2014, 12:01 AM
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I posted this in a similar thread, but I'll repeat it here:
I've done a lot of training in industrial fall protection, and the reason clipping a gated connector (like a carabiner) to another is forbidden is that when the devices are twisted, the gates can be side-loaded. Most gates are weakest if loaded from one side (most climbing equipment manufacturers don't even post the side-load rating for the gate). ANSI 2005 required stronger gates on industrial equipment, but the gate still has a lower rating side-loaded. A bolt won't side-load a gate because the radius of the bolt has been carefully designed to prevent side-loading most biner designs. With non-lockers, twisting can cause opening, but with lockers, the locking sleeve can actually create a hang-up point for the second biner, and cause side loading. Think about biner design, and you can see how the pivot on the gate is a weak point when loaded wrong.
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cracklover
Jul 11, 2014, 12:59 PM
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JTeastAZ wrote: I posted this in a similar thread, but I'll repeat it here: I've done a lot of training in industrial fall protection, and the reason clipping a gated connector (like a carabiner) to another is forbidden is that when the devices are twisted, the gates can be side-loaded. Most gates are weakest if loaded from one side (most climbing equipment manufacturers don't even post the side-load rating for the gate). ANSI 2005 required stronger gates on industrial equipment, but the gate still has a lower rating side-loaded. A bolt won't side-load a gate because the radius of the bolt has been carefully designed to prevent side-loading most biner designs. With non-lockers, twisting can cause opening, but with lockers, the locking sleeve can actually create a hang-up point for the second biner, and cause side loading. Think about biner design, and you can see how the pivot on the gate is a weak point when loaded wrong.
You feel the need to dredge up a seven year old thread in order to repeat what you already posted in another old thread you dredged up?
If what you have to say is interesting - start a new thread. No-one (but you) wants to try to converse with people who have been gone from the site for years.
Cheers,
GO
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Jeff
Owner
Jul 14, 2014, 8:34 PM
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Admin note:
I hid some posts about whether this thread should have been bumped.
In general, bumping old threads is poor netiquette, and it's better to start a new thread.
However, threads like this get a *lot* of traffic from new climbers googling for climbing info, so I appreciate JTeastAZ adding this useful info.
It's unfortunate that this also bumps the thread, but that's a software limitation--hopefully in the forum software I move to, I can code in a feature to "unbump" a thread.
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