Don't know for sure, but I would guess red. I don't see how the biner could normally get cross loaded at those other locations with the angle that's between the spine and gate. Mixed is obviously what is called Sabet loading.
Don't know for sure, but I would guess red. I don't see how the biner could normally get cross loaded at those other locations with the angle that's between the spine and gate. Mixed is obviously what is called Sabet loading.
With friction, I can get a static load similar to green on my heliums. It is hard to see in those pictures, but my red heliums have a change in angle at that notch. It isn't too hard to get a load occuring on the gate.
The blue actually has a bump there to hold it in place as well.
I am also asking for application to all biners. Not everything looks like a helium.
Agreed. I don't know a general definition. I bet it's up to the manufacturer since there's so much difference in geometry. I'd hope with the oval that it's center of gate.
i don't think a cross load could be sustained at red or blue - i think the biner would "flip" and/or re-orient. but if loaded in the center it may last long enough to allow 8kn or so to be seen.
Good question. I would hope the manufacturer would test each and indicate the weakest of the bunch as the cross-load strength. I think this would be a better question for the manufacturers than for this forum. A poll will tell you nothing.
i don't think a cross load could be sustained at red or blue - i think the biner would "flip" and/or re-orient. but if loaded in the center it may last long enough to allow 8kn or so to be seen.
I disagree in the case of heliums. I have them on all of my trad draws and I think that the helium's shape would be most conducive to cross loading as shown by the red arrows (this is assuming that the draw end is loading the spine on the corresponding "red arrow spot", not dead center in the middle of the spine which should allow it to re-orient itself properly). If it loads dead in the center of the spine and gate I think it would have a better chance of "flipping" into another position (possibly that of red).
It is good to note that my opinion doesn't address which is actually the tested cross loading orientation. Good job bringing up such a good question, the only definitive answer would probably be that of the manufacturer.
yes - actually the oval is worst. the taper or asymetrical nature of the spine seen in most other biners tends to deflect the "pressure monent" if you will.
Red Green and blue are all cross loaded. I think in the last picture you would need to have a force description of each arrow before a judgment could be made. There are several arrows that if appropriate force was applied the whole system could cancel itself out or at least be properly loaded.
Ah, not necessarily. If the mechanism applying the load uses smooth bars, the 'biner will likely shift/slide to a point of equillibrium other than where the arrows are drawn in this figure. Good link, but I don't think this figure provides a definitive answer to the question.
Ah, not necessarily. If the mechanism applying the load uses smooth bars, the 'biner will likely shift/slide to a point of equillibrium other than where the arrows are drawn in this figure. Good link, but I don't think this figure provides a definitive answer to the question.
The equilibrium referenced above is clearly unstable for a smooth bar. I think it's implied that something has to fix the bar in place.
Ah, not necessarily. If the mechanism applying the load uses smooth bars, the 'biner will likely shift/slide to a point of equillibrium other than where the arrows are drawn in this figure. Good link, but I don't think this figure provides a definitive answer to the question.
The equilibrium referenced above is clearly unstable for a smooth bar. I think it's implied that something has to fix the bar in place.
I disagree... I don't believe the figure makes any implcation about how the load is applied, other than the general direction (across the minor axis of the carabiner).
Ah, not necessarily. If the mechanism applying the load uses smooth bars, the 'biner will likely shift/slide to a point of equillibrium other than where the arrows are drawn in this figure. Good link, but I don't think this figure provides a definitive answer to the question.
The equilibrium referenced above is clearly unstable for a smooth bar. I think it's implied that something has to fix the bar in place.
I disagree... I don't believe the figure makes any implcation about how the load is applied, other than the general direction (across the minor axis of the carabiner).
As you said, across the minor axis of the biner. How is it going to stay in that orientation without something to fix the point of application of the force? -I know, we're back to the beginning question again. That's why I think it's implied. Now granted, this includes the human element who dreamt up the standard so logic may not be an appropriate tool to use in this discussion.
"Please tell me what biner is cross loaded as defined by the strength ratings"
The strength rating for the minor axis per UIAA is defined as the Green. If you look at the document it says
"... does not contain the full details of the test methods and requirements in these standard..."
This document "defines" minor axis strength rating (which is what the OP wanted). It doesn't address how to anchor and test each style of karabiner. This would be another topic.
as an example "How to setup and conduct a minor axis strength rating test for a non oval biner"
This document isn't specific enough by itself to define anything. Without any details, dimensions, as to location of the application of the force, i.e. half the distance between the ends of the gate, it's open to interpretation.
Personally, I think of crossloading as any loading geometry other than loading along the major axis (axis with largest strength rating). I don't know if a formal definition exists. Therefore, in my opinion, all of the above...
This document isn't specific enough by itself to define anything. Without any details, dimensions, as to location of the application of the force, i.e. half the distance between the ends of the gate, it's open to interpretation.
Yah, exactly. That's my point. And presuming anything from this doc other than the rough definition of what "cross loading" means is a moot point. Discerning the true definition of what cross loadin is as defined by the strength rating (the OP's actual question) would require details about the testing procedure.
Personally, I think of crossloading as any loading geometry other than loading along the major axis (axis with largest strength rating). I don't know if a formal definition exists. Therefore, in my opinion, all of the above...
I concur with this. A "crossload" is any load that doesn't or can't use the maximum strength of the biner. That said, there is probably some element of "crossload" in most any fall - IE. there are no perfect loads. Luckily biners are very strong.
Tom Frost (the engineer who came up with the first modern aluminium carabiner) once told me that his feeling was that if someone could design a biner whose X-load was greater than 12 KNT (I think this is the number he used - it might have been higher) that there would never be a carabiner failure.
The point is that there is a number where biners won't fail. Someone who I know once told me that when they rope solo's they uses a steel biner to attach the Gri because it's so much stronger in the X-load.
I think the number represents it's weakest possible orientation. This is different for every design, so one generic majid-diagram cannot fully represent the entire pool.
Personally, I think of crossloading as any loading geometry other than loading along the major axis (axis with largest strength rating). I don't know if a formal definition exists. Therefore, in my opinion, all of the above...
I concur with this. A "crossload" is any load that doesn't or can't use the maximum strength of the biner. That said, there is probably some element of "crossload" in most any fall - IE. there are no perfect loads. Luckily biners are very strong.
Tom Frost (the engineer who came up with the first modern aluminium carabiner) once told me that his feeling was that if someone could design a biner whose X-load was greater than 12 KNT (I think this is the number he used - it might have been higher) that there would never be a carabiner failure.
The point is that there is a number where biners won't fail. Someone who I know once told me that when they rope solo's they uses a steel biner to attach the Gri because it's so much stronger in the X-load.
Best, Kim
I am not asking for terminology. I am asking to find out how the number stamped on the side of the biner is defined. Since manufacturers are putting a number permanently in the metal of the product, there has to be some well defined standard.
The other guys are heading in the direction I was hoping for, and I think they are bringing up good questions.
One nice biner is the DMM Shield. Superstrong and light, yet they can't do a typical crossload test since it reorients itself from minor axis to major axis. If that were always the case then the crossload strength would be the same as the major axis strength. Of course once in a great while something may cause the biner to get stuck sideways, but it seems this is much less likely than most other lightweight biners, including cheap knockoffs like Madrock made in China.
You don't, actually. Once the frame is notched and the gate aligned against the opposing pin, pressure pretty well keeps it in place for the test.
--ML
having spent more than a few afternoons giving people the factory tour at BD, I can honestly say I have never seen a biner "notched" to maintain its position in the dynamometer.
pins are indeed used, but I seem to recall the tech holding the biner in position while setting the machine under light tension, just enough to secure the biner. the door to the machine is then closed and the test performed to failure.
watching that shit break again and again can be a very educational experience, especially when witnessed in a controlled environment.
be sure to take the tour if you're ever in Salt Lake and have the opportunity to. Check with the retail store for their tour days/times... 2pm IIRC.
You don't, actually. Once the frame is notched and the gate aligned against the opposing pin, pressure pretty well keeps it in place for the test.
--ML
having spent more than a few afternoons giving people the factory tour at BD, I can honestly say I have never seen a biner "notched" to maintain its position in the dynamometer.
pins are indeed used, but I seem to recall the tech holding the biner in position while setting the machine under light tension, just enough to secure the biner. the door to the machine is then closed and the test performed to failure.
watching that shit break again and again can be a very educational experience, especially when witnessed in a controlled environment.
be sure to take the tour if you're ever in Salt Lake and have the opportunity to. Check with the retail store for their tour days/times... 2pm IIRC.
but in the end, you agree it is the centered measurement of green??
You don't, actually. Once the frame is notched and the gate aligned against the opposing pin, pressure pretty well keeps it in place for the test.
--ML
having spent more than a few afternoons giving people the factory tour at BD, I can honestly say I have never seen a biner "notched" to maintain its position in the dynamometer.
pins are indeed used, but I seem to recall the tech holding the biner in position while setting the machine under light tension, just enough to secure the biner. the door to the machine is then closed and the test performed to failure.
watching that shit break again and again can be a very educational experience, especially when witnessed in a controlled environment.
be sure to take the tour if you're ever in Salt Lake and have the opportunity to. Check with the retail store for their tour days/times... 2pm IIRC.
but in the end, you agree it is the centered measurement of green??
for controlled testing purposes, yes. the reality in the field is another matter all together, where any loading other than along the major axis will result in sub-optimal strength.
There is one thing you have not shown on your diagrams which will result in gear failure at much lower loads than cross-loading (as i understand it), that being a load along the major (or any, actually) axis where the 'biner is levered on its side (or spine) over a feature on the rock. Preventing such a situation must be kept in mind when installing bolts or placing gear, and when such situations cannot be avoided perhaps a secondary piece near the primary piece would be considered prudent.
You don't, actually. Once the frame is notched and the gate aligned against the opposing pin, pressure pretty well keeps it in place for the test.
--ML
having spent more than a few afternoons giving people the factory tour at BD, I can honestly say I have never seen a biner "notched" to maintain its position in the dynamometer.
pins are indeed used, but I seem to recall the tech holding the biner in position while setting the machine under light tension, just enough to secure the biner. the door to the machine is then closed and the test performed to failure.
<snip>
Here's the standard:
EN 12275:1998 Paragraph 5.3.2.1.4 Minor axis testing "In order to avoid movement of the loading pins during the test, grooves may be made in the body, in the gate and/or the gate-locking device to sufficient depth to ensure location of the pins. These grooves shall not be subsequently the cause of failure."
Regardless of "correct" crossloading, I wonder what the strength ratings are for the blue and red loads. It's my experience that in real-life scenarios, carabiners are often loaded the red way. i.e. right above the gate. This is especially true with pear shaped carabs.
(This post was edited by sky7high on Aug 23, 2007, 7:13 PM)
Regardless of "correct" crossloading, I wonder what the strength ratings are for the blue and green loads. It's my experience that in real-life scenarios, carabiners are often loaded the red way. i.e. right above the gate. This is especially true with pear shaped carabs.
well the green should be stamped on the biner. The red and blue are the unknowns.
For most biners, I bet the green is the weakest point. So, I feel pretty good if the biner slides to the blue or red positions.
[snip] For most biners, I bet the green is the weakest point. So, I feel pretty good if the biner slides to the blue or red positions.
Well, the red position feels a bit more sketchy to me, because the portion of the carab right above the gate isn't hooked or attached to the rest of the carabiner. If the carabiner is loaded across the gate, the gate is still attached to the carab through the hook or keylock at the nose, but the nose can be folded backwards and it won't have a hook attaching it to the gate.
I don't know if this is clear, I'll try to post an image later
(This post was edited by sky7high on Aug 23, 2007, 7:18 PM)
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Blue.jpg
