Go
The video is invalid since most mfgs use shackles with @ 5 mm in diameter and not some fat shackles that applies forces on the entire upper part and the bottom part of the elbow of the"D".

To make a valid test, he should realistically use a bolt hanger on one side and a 5 mm steel cable or a 11 mm rope.

Shear pins are made of soft metal that shears easily - hence the name. The shear pin is meant to break to prevent damage to the rest of the system which contains much more expensive and hard to replace components like gear boxes, transmissions, bearings, etc....

The video is invalid since most mfgs use shackles with @ 5 mm in diameter and not some fat shackles that applies forces on the entire upper part and the bottom part of the elbow of the"D".

im so caught on this train wreck that its already much too late to jump of, so im trieing to respond:

I dont find it, but didnt you first state that his shackles where to big, and with this theyy cause a levering action, making the pin and hook to engage, wich smaller shakles (or bolt hanger and rope) wouldnt do?
Im not trying to partake in this pissing, match, i really cant find your first statement on this.

i think 5mm diameter is more or less ok. round glue in bolts have about this diameter, and many ropes that are used nowadays also get very thin when wheigted really hard.

marde, where did you find that info on deformations on the biner hook? havent seen that in sicherheit in fels und eis. is it in the new issue, or has it been printed in the DAV panorama?

qwert

Sorry, try again. The UIAA testing video CLEARLY shows them using ~10mm quicklinks to pull the biners. The Breakotron and SMC videos are about the same as well.

Besides, two rounded surfaces perpendicular to each other (i.e. quicklink/shackle to carabiner) will have a very small amount of surface area in contact with each other....

You think I just woke up one day and decided to pick on biner and flood the RC with none sense?

...scientific analysis...

No. I think you wake up every day and decide to flood rc.com with nonsense.

Jay

The way I see it, the pin and the little hook do nothing.
{edit to remove hypothesis}
Alright, I am waiting for the climbing manufacture engineers to explain this myth here.

You think I just woke up one day and decided to pick on biner and flood the RC with none sense?

No. I think you wake up every day and decide to flood rc.com with nonsense.

Jay

theoretically i see what majid is getting at in that the larger diameter, despite the very small surface area contact, would push that contact a little farther away from the spine. HOWEVER, allen brings up a valid point that given the video i've seen and that pdf-file, it seems HIGHLY unlikely that changing from approx 10mm links to something smaller would result in anything "more realistic to the field" than the results found.

also, i noticed that as soon as the biner began to warp, the bottom link started sliding toward the gate. i bet the same thing would happen with a smaller diameter link.
PLUS, in any real world application the software on one side of the biner (rope or what have you) would distribute its force over AT LEAST the area that the links are.

maybe you should do that test, majid (or get somebody to do it). i kind of see your hypothesis with the diameter issue, but my guess is that you'll see pretty much exactly the same thing.

theoretically i see what majid is getting at in that the larger diameter, despite the very small surface area contact, would push that contact a little farther away from the spine.
...

more stuff here


http://web.mit.edu/...lation_overview.html

The coupling of energy from an oscillating rope to a carabiner gate has been implicated as the culprit for gate opening [1, 2] but this phenomenon has not been investigated in a systematic manner. Carabiner failure is relatively rare, but open gate failures make up the majority of failures [?]. In general, the open gate condition is blamed on poor luck, initial conditions that cause the carabiner gate to catch on the cliff surface, or the sudden impact of the carabiner on the cliff surface [?]. In a recent incident in Holland however, no such explanation is likely, which makes one wonder whether the rope oscillations might be more common than is expected (figure #)[].

Evidence suggests that rope oscillations are common and significant in magnitude. Photos taken of climbers (figure #) show such oscillation, and any belayer whose climber insists on hangdogging for long periods of time can break up the boredom by ?plucking? the rope to make it oscillate like a guitar string. Further evidence may be available from drop test data, where the sine wave form of the tension vs. time exhibits an added sine wave whose frequency is several times that of the deceleration of the falling mass (figure #).

To evaluate the likelihood of rope oscillations causing carabiner gates to vibrate open, this project develops a model for when rope oscillation is prone to opening carabiner gates and tests rope and carabiners to veryify the model.

Go
The video is invalid since most mfgs use shackles with @ 5 mm in diameter and not some fat shackles that applies forces on the entire upper part and the bottom part of the elbow of the"D".

To make a valid test, he should realistically use a bolt hanger on one side and a 5 mm steel cable or a 11 mm rope.

trench

I am saying that, small modification to current pin-hook on some carabineers may reduce the biner failure during typical climber's fall.

An open gate biner looses over 2/3 of it’s overall strength during a fall. That is not 10% or 30% reduction but over 60%. That makes a big different in having a climber live after a typical fall up or let his family deal with his funeral over the $6.00 biner.

Loosing 60% of biner overall strength due to an open gate is not a small change that we should just accept and sleep with it.

That is my message.

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 .

Theoretically, when a climber falls, his biners are attached to a protection of some sort that has less than 5 mm in diameter (bolt hanger 3mm. cams, 3-5 mm, nut, 2-4 mm, hex, 3-6 mm….etc) and a rope which under massive tension( fall factor) becomes half of its original diameter.

When was the last time you clipped in to a 12 mm bolt hanger or a 10 mm cam?

This will only occur if the inner radius of the bend of the carabiner is smaller than the radius of the rod used to pull on the carabiner. Otherwise, the 10mm pin will contact the carabiner exactly where the 5mm pin will.

You won't find many (if any) carabiners with a bend radius smaller than the radius of the largest rope you'd expect to use with that carabiner. Such a bend would tend to pinch the rope and bind.

more stuff here


http://web.mit.edu/...lation_overview.html

The coupling of energy from an oscillating rope to a carabiner gate has been implicated as the culprit for gate opening [1, 2] but this phenomenon has not been investigated in a systematic manner. Carabiner failure is relatively rare, but open gate failures make up the majority of failures [?]. In general, the open gate condition is blamed on poor luck, initial conditions that cause the carabiner gate to catch on the cliff surface, or the sudden impact of the carabiner on the cliff surface [?]. In a recent incident in Holland however, no such explanation is likely, which makes one wonder whether the rope oscillations might be more common than is expected (figure #)[].

Evidence suggests that rope oscillations are common and significant in magnitude. Photos taken of climbers (figure #) show such oscillation, and any belayer whose climber insists on hangdogging for long periods of time can break up the boredom by ?plucking? the rope to make it oscillate like a guitar string. Further evidence may be available from drop test data, where the sine wave form of the tension vs. time exhibits an added sine wave whose frequency is several times that of the deceleration of the falling mass (figure #).

To evaluate the likelihood of rope oscillations causing carabiner gates to vibrate open, this project develops a model for when rope oscillation is prone to opening carabiner gates and tests rope and carabiners to veryify the model.

5 mm is the industry's standard used by most mfgs .