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majid_sabet
Mar 11, 2008, 5:01 AM
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I been looking at biner failures for long time and recently I reviewed the UIAA test page that offers several films related to biner failures during pull test. it seems to me that locking pin on the gate does not appear to catch the hook during shock load or pull test.
Does this pin and the hook do anything useful ?
Does it increases the biner KN strength by any amount if pin catches the gate?
If so, then why in many causes, the applied tension causes the pin and the hook not to interlock ?
[URL=http://imageshack.us]
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hosh
Mar 11, 2008, 6:13 AM
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majid_sabet wrote: I been looking at biner failures for long time and recently I reviewed the UIAA test page that offers several films related to biner failures during pull test. it seems to me that locking pin on the gate does not appear to catch the hook during shock load or pull test. Does this pin and the hook do anything useful ? Does it increases the biner KN strength by any amount if pin catches the gate? If so, then why in many causes, the applied tension causes the pin and the hook not to interlock ? [URL=http://imageshack.us][IMG]http://img357.imageshack.us/img357/7801/bentcarabine22bh8.jpg[/IMG]
Possible gate flutter?
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dobson
Mar 11, 2008, 6:41 AM
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majid_sabet wrote: If so, then why in many causes, the applied tension causes the pin and the hook not to interlock ?
Could you show me a few examples of these "many causes (sic)".
Looks to me like the biner in this photo was loaded open-gate. Possibly flutter.
All of the videos I've seen of pull tests show the nose loading on the gate right up to failure.
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viciado
Mar 11, 2008, 10:06 AM
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Not sure I can understand my own rationale in supporting him (heh heh), but I agree with Majid.
The http://www.theuiaa.org/act_safety.htmlseems to show the non-lockers deforming in such a manner that the pin and hook of the visibly closed gate do not engage. I also wondered about that, but haven't had the chance to do anything about fnding out more.
Edited to add:
I just looked at the video again. I paused on the two biners just after the gate opened (no actual flutter). It appears to me that the "color" in the hook does not match the back ground. Could it be that they used a filler of some sort to simulate the action of flutter by keeping the pin from fully engaging? Just a thought. It would be nice to see some commentary along with the video.
(This post was edited by viciado on Mar 11, 2008, 10:37 AM)
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reg
Mar 11, 2008, 1:26 PM
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majid_sabet wrote: I been looking at biner failures for long time and recently I reviewed the UIAA test page that offers several films related to biner failures during pull test. it seems to me that locking pin on the gate does not appear to catch the hook during shock load or pull test. Does this pin and the hook do anything useful ? Does it increases the biner KN strength by any amount if pin catches the gate? If so, then why in many causes, the applied tension causes the pin and the hook not to interlock ? [URL=http://imageshack.us][IMG]http://img357.imageshack.us/img357/7801/bentcarabine22bh8.jpg[/IMG]
what i see is the stress applied in the "bucket" has caused a miss alignment of the pin and catch or the catch angle changes disallowing the connection. seems a locker would not suffer that.
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walkonyourhands
Mar 11, 2008, 2:18 PM
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I think viciado has got it right...the vid seems to show an open-gate test where the nose of the biner has been covered with transparent tape to keep the gate from catching the nose.
I remember a description of the testing methodics on the old UIAA page, but they seem to be gone.
Some description to the vids by the UIAA would be real nice.
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coach_kyle
Mar 11, 2008, 2:32 PM
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Think of the biner as a lever with the fulcrum at the spine. Because the load (rope) is much closer to the fulcrum than the counteracting force, (the pin in the gate), the force from the pin doesn't have to be nearly as large in order for the total torque about the spine to be zero. It's the same concept as pushing on a door right next to the hinges rather than at the knob.
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patto
Mar 11, 2008, 2:47 PM
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majid_sabet why do you make these posts?
Unless I am overestimating your intelligence you already know the answers here.
As others have said of course the pin is useful. And I dispute your claim that many cases applied tenesion causes the pin and hook not to interlock.
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trenchdigger
Mar 11, 2008, 3:06 PM
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majid_sabet wrote: I been looking at biner failures for long time and recently I reviewed the UIAA test page that offers several films related to biner failures during pull test. it seems to me that locking pin on the gate does not appear to catch the hook during shock load or pull test .... If so, then why in many causes, the applied tension causes the pin and the hook not to interlock ?
I heard of this occasionally happening, but more often due to the carabiner gate contacting the rock and being pressed open (hence the usefulness of a locker) and some theorization about it occurring due to gate flutter.
Can you provide some evidence that this is a regular occurrence? Can you show any case where the carabiner gate pin failed to catch the notch simply due to "applied tension" to the carabiner? I really don't see how this is possible.
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antiqued
Mar 11, 2008, 4:31 PM
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The first UIAA video shows two asymetrical D biners breaking. The first one (~20-25 sec) clearly shows that the notch in the biner has been wrapped with transparent tape, preventing the pin from engaging. The tape wrap is sloppy and extends beyond the biner.
I can't see that in the second one. Perhaps a neater wrap? Majid, have you written the UIAA and asked?
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dingus
Mar 11, 2008, 4:34 PM
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Many times the notch in the biner gate has caught what otherwise would have been a lost nut.
There's that....
DMT
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majid_sabet
Mar 11, 2008, 5:06 PM
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The way I see it, the pin and the little hook do nothing. Basically, they are both worthless and I am pretty confident that, this is the biggest Screw-up in the history of climbing gear design and yet, manufactures are still making them with the same problem
The pin does not interlock with the hook under tension period. If the hook is there to stop the gate from bending backward (extend travel) then they could just cut the notch and keep the hook straight like a regular Chinese key chain biners .
If the notch is there to interlock with the biner then our great mechanical engineer who keep designing these biner should know that applied tension to the axis line causing the lower part of the biner to bend as well which eventually shift the angle of the hook to miss the pin by 0.00001 (whatever distance) .
Would it be logical to design the shape of the hook (or the gate) in a way that engages with the pin not at its normal (unloaded condition) but during the loading phase so it could actually engages with the pin to keep the gate closed?
Alright, I am waiting for the climbing manufacture engineers to explain this myth here.
[URL=http://imageshack.us]
(This post was edited by majid_sabet on Mar 11, 2008, 5:07 PM)
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trenchdigger
Mar 11, 2008, 5:12 PM
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majid_sabet wrote: The way I see it, the pin and the little hook do nothing. Basically, they are both worthless and I am pretty confident that, this is the biggest Screw-up in the history of climbing gear design and yet, manufactures are still making them with the same problem The pin does not interlock with the hook under tension period. If the hook is there to stop the gate from bending backward (extend travel) then they could just cut the notch and keep the hook straight like a regular Chinese key chain biners . If the notch is there to interlock with the biner then our great mechanical engineer who keep designing these biner should know that applied tension to the axis line causing the lower part of the biner to bend as well which eventually shift the angle of the hook to miss the pin by 0.00001 (whatever distance) . Would it be logical to design the shape of the hook (or the gate) in a way that engages with the pin not at its normal (unloaded condition) but during the loading phase so it could actually engages with the pin to keep the gate closed? Alright, I am waiting for the climbing manufacture engineers to explain this myth here. [URL=http://imageshack.us][IMG]http://img522.imageshack.us/img522/521/81798928iq1.jpg[/IMG]
T0... c'mon man, you've done better in the past.
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antiqued
Mar 11, 2008, 5:24 PM
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majid_sabet wrote: The way I see it, the pin and the little hook do nothing. Basically, they are both worthless ]
Majid - if that is the case, how do you explain the different test results - open gate vs closed gate?
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majid_sabet
Mar 11, 2008, 6:15 PM
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antiqued wrote: majid_sabet wrote: The way I see it, the pin and the little hook do nothing. Basically, they are both worthless ] Majid - if that is the case, how do you explain the different test results - open gate vs closed gate?
Is this involved with biners that have a pin or a gate that comes with a locking latch?
In either way, I like to see pin breaks, bent, snap or the hook come off before the biner begin to bend.
Here check out this film
http://www.theuiaa.org/act_safety.html
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Roasta
Mar 11, 2008, 6:33 PM
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From what has been said, it seems fair to say that a biner with a larger 'bucket' then top section is more likely to flex and render the notch useless. What about an oval biner where there is more symmetry - would the flex be equal at each end bringing the notch back into action?
Or if the load was applied to the gate side of the top of the biner and at the spine side on the bucket; shouldn't the top portion of biner flex more, the bucket less, again bringing the notch back into to play??
(This post was edited by Roasta on Mar 11, 2008, 6:35 PM)
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clintcummins
Mar 11, 2008, 7:02 PM
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Like others said - the notch on the first biner was taped, so it is the open gate test.
For the second biner, the footage starts with the biner already stressed and the pin past the notch. So probably the gate was held open while the biner was stressed and then let go, once it could not engage the notch. Maybe they were just trying to save on tape? :-) Deceptive editing - perhaps their marketing people were in charge?
Conclusion: both are open gate tests. Perhaps they should be more clearly marked as such, but there was really no descriptive text attempted in these video clips.
Majid, are you just trolling, or are you serious that the notch and pin do not add strength?
(This post was edited by clintcummins on Mar 11, 2008, 7:05 PM)
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majid_sabet
Mar 11, 2008, 7:14 PM
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clintcummins wrote: Like others said - the notch on the first biner was taped, so it is the open gate test. For the second biner, the footage starts with the biner already stressed and the pin past the notch. So probably the gate was held open while the biner was stressed and then let go, once it could not engage the notch. Maybe they were just trying to save on tape? :-) Deceptive editing - perhaps their marketing people were in charge? Conclusion: both are open gate tests. Perhaps they should be more clearly marked as such, but there was really no descriptive text attempted in these video clips. Majid, are you just trolling, or are you serious that the notch and pin do not add strength?
Clint
I seen plenty of failed biner where I thought the notch should at least break apart or pull the pin out but ,it seems like they barely miss each other and do not interlock during taking load.
(This post was edited by majid_sabet on Mar 11, 2008, 7:16 PM)
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irregularpanda
Mar 11, 2008, 7:21 PM
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patto wrote: majid_sabet why do you make these posts? Unless I am overestimating your intelligence you already know the answers here. As others have said of course the pin is useful. And I dispute your claim that many cases applied tenesion causes the pin and hook not to interlock.
I agree. This is probably the dumbest post I've seen by Majid. Maybe the guy towed a car with it. Maybe he found the QD. Either way, he's a troll who is showing us pictures of messed up carabiners without any explanation.
Seriously though, does the pin do anything? Retarded question.
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majid_sabet
Mar 11, 2008, 7:27 PM
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Sorry dude but this does not count due to fact that this individual tester ( Bob) is using a fatter hook to pull the biner.
The lager hook applies the tension in the middle of the biner (on both ends) therefore the applied forces are not focused at the axis line but divided along the lower and the upper part causing the biner to be pulled like from both side evenly till one side gives up.
When you use rope or the protection, you are using much smaller size connection such as ¼ inch steel wire therefore, majority of forces are applied along the axis line and not in the middle of the biner. Even the 11 mm rope under massive tension become narrower and still transmits forces along the axis line rather than in the middle of the biner.
Note: we are not talking about using locking biners here so let keep the topic focused on non-lockings.
(This post was edited by majid_sabet on Mar 11, 2008, 7:32 PM)
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GiantClimb
Mar 11, 2008, 7:33 PM
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majid_sabet wrote: ...I am pretty confident that, this is the biggest Screw-up in the history of climbing gear design and yet, manufactures are still making them with the same problem [URL=http://imageshack.us][IMG]http://img522.imageshack.us/img522/521/81798928iq1.jpg[/IMG]
It was hard before but it is now officially impossible to take you seriously anymore.
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tolman_paul
Mar 11, 2008, 7:37 PM
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acorneau wrote: majid_sabet wrote: The way I see it, the pin and the little hook do nothing. .... The pin does not interlock with the hook under tension period. Of course it does! Haven't you ever sat in your harness on a carabiner in front of your face? You can watch the carabiner bend until the pin connects with the nose. In reply to: Some biners will have their gate held shut under bodyweight, others don't. I need to post the picture of a steel locking biner that failed in the same manner as the shown biner (I was using it to pull someone out of a ditch, don't tase me bro) I know I shock loaded that biner but was suprised to see it fail, though perhaps I didn't completely lock it.
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majid_sabet
Mar 11, 2008, 7:43 PM
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GiantClimb wrote: majid_sabet wrote: ...I am pretty confident that, this is the biggest Screw-up in the history of climbing gear design and yet, manufactures are still making them with the same problem [URL=http://imageshack.us][IMG]http://img522.imageshack.us/img522/521/81798928iq1.jpg[/IMG] It was hard before but it is now officially impossible to take you seriously anymore.
Show me bunch of biner that shows pin got pulled out or the notch got snapped right of the biner during pull test or an actual fall then you will see if my statment makes any sense or not.
edit to add;
RCers and to member of the LAB community
Instead of keep posting unrelated comments to this post, please post some images of a biner pin been pulled or the hook been snapped in half during a pull test.
Post as many as photos as you can you can so I could give up on this myth.
(This post was edited by majid_sabet on Mar 11, 2008, 7:49 PM)
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irregularpanda
Mar 11, 2008, 7:49 PM
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majid_sabet wrote: Show me bunch of biner that shows pin got pulled out or the notch got snapped right of the biner during pull test or an actual fall then you will see if my statment makes any sense or not.
You know, you could do that too, instead of using somebody else's (totally unsubstantiated) picture of said failure. In fact, do that now.
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