I'd like to see a comparison of the breaking strengths of light-weight I-beam carabiners with carabiners made from conventional stock when loaded over an edge. The rated strengths of these biners are similar, but I've always been suspicious of how the newer biners would fare if loaded over an edge.

Jay

My brother has a mechanical engineering project coming up and he wants to do some tests on climbing equipment for it. I'll be helping him with it, so my question is, is there anything specific that anyone would like to see done? Anything that may have been hard to do due to money or lack of equipment? He has full access to testing equipment (specifically what, I don't know, but I can always ask him if anyone has specific questions about that) and a 400 dollar grant from the university to buy test gear with. The tests will be taking place over the course of the winter, but he needs input quickly to buy the gear to test.

I'd like to see a comparison of the breaking strengths of light-weight I-beam carabiners with carabiners made from conventional stock when loaded over an edge. The rated strengths of these biners are similar, but I've always been suspicious of how the newer biners would fare if loaded over an edge.

Jay

Would DMM Big Boa and Petzl Attache be suitable gear for the I-Beam vs Conventional Carabiner test?

I'd be interested to see testing of different knots in strands of dyneema slings. In other words, if you needed to build an anchor using v-threads and your only option was to cut and retie dyneema slings, what knot would be the strongest? I've heard a lot of speculation about this, but have seen no hard data.

I've always been curious about the effect of pairing two locking biners (opposite & opposed) on their strength. I'm curious if it's weaker than two non-lockers, or one locker & one non-locker. The hypothesis is that the locking mechanism applies sideways loading to the gate because of pressure from the other biner.

I'd be interested to see testing of different knots in strands of dyneema slings. In other words, if you needed to build an anchor using v-threads and your only option was to cut and retie dyneema slings, what knot would be the strongest? I've heard a lot of speculation about this, but have seen no hard data.

Do you have specific knots you want to see done other than the general figure eight, overhand, waterknot, etc.?

Just out of curiosity, what would be the practical application of that? Meaning, at what point would just one loop get cut but not the other? I only use DFE for belay anchor so I can't see it getting cut in that situation, but you may use it for way more than I do. But DFE with one cut loop would be an interesting test. Do you think getting multiple brands of rope along with different sizes would be good, or should we stick with a uniform brand of rope? Don't know if that would make a difference

It's a good knot for when you need to adjust the size of the two different loops easily.

I can't really see one side getting cut without the other either, but it's a common argument that people use to to explain why bunny ears are not safe to use.

Using a couple different sizes for testing would calm other fears that the one ear may remain intact depending on the size of the rope used. It would be a more thorough and wider excepted test.

It would be nice to put this myth to bed.
Thanks for considering.

Thanks.

Since many of the thinner dyneema slings are almost round in cross section, I would add a triple fisherman's. If I were doing the testing, I'd leave out the figure eight since it is generally accepted that a figure eight capsizes under a relatively small load.

How about building a fixture that is basically 2 parallel plates with interchangeable faces and adjustable angles. Maybe have a c channel to capture the stone block so you can just drop it in. Hopes that makes sense. Vary the angles between the plates from parallel to 30º flaring in several increments. Test pullout strength of some of the fancy new cams and see if they really hold better.

How about building a fixture that is basically 2 parallel plates with interchangeable faces and adjustable angles. Maybe have a c channel to capture the stone block so you can just drop it in. Hopes that makes sense. Vary the angles between the plates from parallel to 30º flaring in several increments. Test pullout strength of some of the fancy new cams and see if they really hold better.

How about cutting one loop (ear) on a Double Figure Eight (Bunny Ears) and pull test the other loop to failure. Would like to see if the loop will pull thru (as many speculate) or if the loop will break. You could use a couple different widths of dynamic climbing rope around 9mm-11mm.

I'm sure you already know to dress and set any knots you guys decide to test.