Excellent testing, as a climbing arborist I find this content very interesting and helpful. I do this type of attachment all the time in trees, but only for positioning when using a carabiner, never for main life support, where I typically will use a Notch Quickie instead just to be sure. I've always felt that the dangers of loading carabiners like this has been a bit exaggerated by many people, especially when used on thicker branches and stems, but I must admit that these results still surprised me as they're way better than I would've thought. Super good enough! 😁👍
Hell yeah dude, sounds like you've been more conservative than me 😅 I've had quite a few co-workers nag me about this and just rolled my eyes at them, so this video is super vindicating enough 😂
@@corygrossman1 Indeed! Even though I've always *felt* that the danger was exaggerated by many people, I've had no data to back up that feeling and so I've chosen to be very conservative with this just to be extra careful. I will probably be using this a lot more now going forward, but knowing myself it will probably be with a 50 kN steel carabiner just to be *extra* sure. 🙈😅 Climb high and stay safe mate.
They all seemed to fail by shearing off the hinge pin for the gate and then breaking/bending around the contact point with the pipe. I think it comes down to the ratio of carabiner length to the diameter of the object you are clipped around. With a large diameter anchor point the carabiner sees a pretty gentle bend radius, not enough to shear the hinge pin for the gate. With a tiny diameter pipe the rope almost passes through the carabiner parallel to the spine so cross loading is minimal. I would bet if you tested a bunch of diameters that range from super small to larger than the length of the carabiner, you would find a sweet spot where the pipe is both small enough to have a tight bend radius, but large enough to get the angle at which the rope passes back through the carabiner steep enough (relative to the spine) to cause cross loading. A graph of the diameters vs break strength would likely have an inverted bell curve where the strength decreases until the "sweet spot" and then climbs back up to MBS range. If all that is true then the "sweet spot" could probably be described by the angle the rope passes through the carabiner relative to the spine, giving a "Danger Zone" of angles to visually tell if an anchor like this would be significantly weaker than MBS.
Yess!!! Love the arborist stuff! I was hoping you'd do some testing on this. I recently switched to a steel carabiner for this application. I see that probably wasn't necessary 😅 Personally, I'd love to see some pull and dropp tests with the rope runner pro. Maybe even on different ropes. But I get that I'm probably one of eight people interested in that 😂
If you have access to the pipe/branch, loop the rope over, and secure with a Stone knot using the carabineer instead of the fiddle stick. It takes the carabineer bend out of the equation.
I have done this quite a bit, even for anchors 😄 Only ever bent an I-beam style aluminum locker after using it to rig up slings like a chocker cable to haul small trees/branches with an excavator because looping slings or using shackles were too time consuming and inconvenient for the potential risk... (and I wanted to see if it would break, which is why I didn't use a retired steel locker) But I kind of have dedicated life protection hardware and separate used utility hardware that never get mixed up... I honestly expected the aluminum one to break because it was taking some weight and even shock loads "for research" but it just ended up with buggered threads and a gate that didn't line up because of the bent spine before getting tossed... (If OSHA or other people that consider this blasphemous behavior are watching, then this all occurs in Mine Craft of course) 👍
4:24 dyneema is very slippery. A nylon rope has more friction around the pipe which results in a lower percentage of the force acting on the carabiner. This could be the reason that the biner breaks lower with the dyneema
As an arborist, I'd like to see how a branch fresh out of the tree would hold against the branch test you did. (Assuming the branch used wasn't fresh of the tree😊 It looked dead & dry with light decay) Love the video!❤ Super usefull enough info in there!
That’s really interesting. I don’t climb anymore because I’ve switched over to kayaking. In whitewater boating we use 3:1 for freeing pinned boats. There is a lot of discussion about anchors, carabiners, slings, and rope breaking strengths. It looks like for that application our gear is super good enough.
I always wondered how safe that was. Arborists often tie off a line like that when they're in the trees doing their thing. Cool to watch, and I was curious how much that hurt the ratings. Now I know.
Hey great idea - for arborist types, could you try an alpine butterfly (AB) to a steel (and then aluminum) biner choked around a vertical stem - 4" stem (~ the minimum this cringing chicken would climb on spurs)/ 6" stem/ 8" stem to see if the knot and stem radius makes any difference. Maybe the choke doesn't even work on a 4" stem unless it's rope and ring? The choking biner thingy may be used on branches but there's lots of options there including just rope , all the way to Texas Tug etc. For stems tho, guys use Notch Quickies/ AB to steel biners to Al biners to rings to inventions on TreeBuzz as yet unproduced. Keep up the good work. Why you could even work up a proof of something to eventually change the practice in the ANSI Z133 !!!! Gosh!
Seeing the results of the tests with the SMC and Omega Pacific carabiners, I'm glad that I invested in buying both. I would never load them that way, but it's good to know that they'll hold up long enough to be used in an emergency evac situation if needed.
Sorry I have a question that for sure was asked before quite some times: How comparable is a quasi static pull with a shock load of a fall? Would it give the same results?
I would like to see you test wrapping the rope around the back of the carabiner once. we do this at work all the time to prevent crossloading. it never slips under "normal" conditions, but i wonder what it would take for it to slip.
I’ve gotten side load carabiner comments on my videos and this reinforces my theory that if the limb/trunk is not too small it’s likely just fine. Also I’ve negative rigged some big pieces on steel carabiners and never bent one yet.
One method I was recently shown is to clip the rope through the biner twice (it ends up spiraled around the spine of the biner once). This seems to position the biner to prevent side loading, but I'd like to know what other forces it puts on the system, and if the extra bend in the rope weakens it.
It's funny how many times I have seen the "you're side loading your carabineer" comment on tree climbing videos. This seems to prove what I thought, they were meme or troll.
Dude, those people didn't have the information that you have now. It's good practice to be conservative with personal safety practices until something is proven to be save.
The only reason I was concerned was because there were so many people saying you would die if you "cross load" a beener when using it to cinch a rope around a tree. Fuckin idiots.
A thin bransch (of steel) does put a lot less stress on the carabiner since it's less leverage on the carabineer, just like over an edge nor protruding a lot.
I fail to understand why you'd ever do this, if you have much better alternatives such as an anchor knot or mast hitch with a slip knot. That's what we use in mountain rescue in Germany. For us, it's all about minimizing the amount of equipment you need and building absolute mount points without using carabiner at all, for example. Perhaps it's the different use cases of equipment...? When we build a system, we build it to carry the full 22 kN with at least one backup. For certain rescue techniques, we easily get 15 kN of force on each of the sides which is why we love strong trees and never loading carabiners on their cross axis. Sadly, many trees have been destroyed by fire and bark beetles last year in our areas; some places look like a moon desert.
Just a thought: I'm sitting on a roof and just got roofing felt tar on my rope. My Petzl Rig suddenly isn't super happy, but I'm just wondering, what happens with tar on a rope? Is it still super good enough?
So the little pipe creates a bigger moment arm which means more force multiplication. The bigger the pipe the closer you get to it behaving more like a 1:1 pull on a flat surface.
M12 threaded bolt has a 2ton (metric) shear strength but only a rated bolt. If the ends of the all thread you used were not fixed it would have collapses at half that.
There are different aluminium alloys. They behave different. The really hard AW 7075 stuff cannot be welded and is very affected by seawater. AW 6082 is a nice one. It's the most hardenable seawater resistant one. (Sea water resistancy is always relative of cause.) AW 7020 is harder as AW 6082 and weldable but not sea water resistant. 6060 is the most common one in extruded stuff. (AW=aluminium wrought) It's similar to 6082 but it's less hardenable. It's sucks to mill that stuff. AW 5084 is the most self hardening one. It's used for ships. Milling that is APITA. Even softer is AlMg3 (Idk the number.) It's very common for sheets. It's softer as 5084 (AlMg4.5Mn). I've not included cast alloys. The Grigri has eventually cast parts. The softer the alloy is, the more you can bend it. I'm using a 6082 tube in some of my suspension forks (the QR9 version). To bend it in the radius I need I have to keep it one hour at 530′C, quench it and bend it immediately. In it's hardened state (T6) it's still more ductile as 7075 and maybe the material the bent carabiner was made of.
the Z2R how little momentum would in theory be enough.. not referring to ease of comfort for the pulling, but simply how small a modern brushless rotary powertool could you get away with and still deliver enough torque for licting the average male adult.? some of these modern 12v and 18v drills.. deliver a surprising amount of torque for their size. with modern high current IMR/INR LIion cells
11:00 If that was a real tree and I was repelling off the rope I would put the rope where it isn't rubbing on the bolt, but its good to know you can still get 14 kn out of that.
I'm taking a break from calculating the pullout force for some lag screws going into PSL engineered lumber for anchoring a railing on a roof deck... and the highlight of this video for me is that the bit of branch held 6+ kn. (But overall, these test scenarios screamed "Oh no! Not that! Take a second and rig a better anchor!" even if some of them would be fine for a rap.)
I don't know about others but I don't use all thread for trees. Rigging for me is usually to the bolted branch. I don't use AT because it rusts faster and is hard on ropes.
In tree work i do this all the time with a beefy steel triple locking biner, a butterfly knot and an extra manual locking biner because i always had the most fear of accidentally opening the gate. Thank you for testing this! Many people tried to stop me doing this before.
Arborist rigging typically involves the use of half hitches to take more than half the load before the carabiner, so it'd be interesting to see that tested. I always enjoy when you add more content related to arbs & rigging. Thanks for the vid.
I want to see the small diameter tree branch than can support 15kn... Okay, actually thoughtful comment, I suspect the threaded rod was the culprit in a lot of the rope/sling breakage. Especially that relatively non-static rope around the log, the cover was pretty clearly cut by the threads on the bolt. (TL;DR: super good enough)
It's not often that someone would tie off mid branch. Typically we aim to get into a union and or around a main stem with a branch just preventing slippage. But yeah all of these numbers have been "super good enough"!
Hey, as we again saw the large diameter pipe. If you are worried about necking in the future, fill the hollow internal with concrete. Its is strong in compression.
I’ve been practicing some rappel techniques in my basement off of a pull-up bar using a system kinda like this, except I use 3-4 wraps around the pipe to help keep the carabiner from going wonky and the pipe and rope from getting damaged over time
I would leave a comment but Google has made it impossible to read and write comments. Feels like a fucking newspaper column and far from desirable to interact here.
To get a piece of tree debris to weigh enough to create these kinds of forces (even at shock load) they have to be high diameter pieces, which would negate most of these tests because the angular tensions shown here won't exist, as the clip would be mostly flat against the wood, which would deform to the shape of the clip before the clip deforms. Like, your never going to get a 3 inch branch to weigh enough to damage a clip. Even a 12" branch would be unlikely. Bigger than that and the sharp angular forces against the side of the clip start to dissappear,as seen in the last test. I think the biggest concern is the carabiner coming unlocked
and for the last concern, just use triple-lock carabiners (the one used in belaying). While it may be an overkill, chances that something go wrong will be diminished to so high load, that probably carabiner won't be a weak point anyway.
This video made me feel a lot better about my tree anchors I used with carabiners + rope years ago. I’d love to own a Z2r, but I’ll just enjoy you messing with them!👍
Depends on species, but experienced climbers will sometimes go as small as their wrist or forearm. Takes some experience to feel confident in what's super good enough and to learn how to not amplify forces.
Maybe some insight, or maybe I am wrong, good chance I am, but I like to put formula to things. Carabiner roughly 30 deg from pull direction: sin(30) * 31Kn = 15.5Kn
I’ve seen some people use that on their personal anchor, sometimes while standing above the anchor. Maybe a fall factor 2 drop test can be interesting 🤷 Thanks for the great content!!
Have you ever watched East Coast RU-vidrs that rappel into caves? Mineral dude and ActionAdventureTwins show off single rope rappel and ascend without extra safety equipment. It is cringe worthy, if you need some entertainment! They show off the Petzl Ascension, belay rack, and a horned figure 8. Maybe you can see what else they are using.
I'm actually really curious about this kind of choking around some sort of anchorage... I come from a construction background where we would have a 5/8" diameter lifeline with a spliced eye and a snap hook installed on it and we were always taught that if we did not have an engineered anchor or embedded anchor to clip to.... it was fine to wrap it around a piece of Anchorage and clip it back to itself as long as we think whatever we were wrapping it around would hold 5,000+ pounds.... Oftentimes that meant large concrete columns in towers or open web steel joists... Is this safe? I know a lot of people working in construction would love to find this out.
Thank you so much for these tests and for putting time and effort into them. Still, I want to point out the fact that pulling something with hydraulic is not as real as it is in real action, I believe that the shock test is better since it often happens in sports and industry practice, let's say we are hauling something around 100 Kg to 40-meter high. We have 2 anchors on it, the top anchor suddenly breaks and now we have a shock load on the bottom anchor. Again, thank you. I have been following your RU-vid channel and have learned a lot.
Every arborist on here wants you to do this again with the types of carabiners we use... because we know we shouldn't... but you know... hypothetically how much can we get away with :)
From my experience, of R.A., stunts, and arbor, most of your soft goods ar breaking due to the "sharp" edge of the All thread. Try wrapping the all thread in e tap , card board ,carpet, you k ow the usual gag that people use on set ups, and go from thwre?... also curious to what a full wrap around thw tree I.e. a frictionless hitch does to bend and break the carabiner as then you have direct forces applied to just the bend of the line bending the link over the object?!
Thanks for the testing. I'd guess the thin branch test where the sling broke and you wondered how it did that at ~21kN was due to the threads cut the sling. you basically put all the preasure at a couple very small reas which are often not exactly smooth. Especially bad if you pullover such stuff like in the last test. I used pieces of garden hose over small diameter metal stuff to protect the rope. Might not truust my life with that but for rigging stuff it works
Would it be affected if the “pipe” wasn’t smooth? Like if it was 1” allthread, would the threads cut into the rope and/or damage the surface of the carabiner?
I hitch off to stems in tree work this way all the time down to about a 4" diameter. Was pretty sure it was super good enough but nice to have it verified as people have called me out for it. I do like to use a fall arrest rated carabineer which is speced for a 16kn side load. If I am going for a smaller diameter I toss a half hitch below it to take some load off. How big was the pipe in the video?
So take a steel biner and sideload as much as you want. Ive been using aluminum to cinch when going srt finishing a tree but that's 10 inch plus diameter. I guess im not worried at all now. Thanks.
awesome test, loved the results. I think that he carabiner it's not being loaded with the full force because a lot of it it's being "losed" on the priction of the rope on the pipe
Good video. I'd like to know if there's any issue with using an aluminium ring, wrapping around branch, a loop back through the ring with a carabiner blocking and barrel stopper on the end. Rings are cheap and seem much better for this purpose, also stays nicely on the rope. I got a 70kn rated steel one just for extra safety but I imagine its ok with the 30kn DMM alu one.
Very likely! try spinning a stainless allthread stock while Grabiii6ng it hard , it may cut your hand , Roll /press formed normal threads is more rounded on the ridges, and actually stronger than cut dito due to the fibers in material not being cut of when making the threads.
Your pipe is probably expensive, maybe you should fill your pipe with concrete to prevent it from crushing more. Maybe a 1" PVC pipe in the middle so you can run your restraining cord through it.
if you think about it, if you ever want to carry the system into a mine or other places it would make sense to use a direct current pump, and if you don't want to disassemble and reassemble critical parts of the system it would make sense to use that same pump at home too, that way you just put the whole thing in a van and you can be sure it still works when you need it with no downtime. everything is a compromise. he could have two different pump in parallel for the different scenarios, but why bother when the battery getting low is rarely a problem?
That's crazy, I was just thinking of messaging you about this this evening. Sometimes when I'm caving my cows tails (lanyard) is attached to the rung of a ladder using a grivel plume just like this.
I’ve questioned the arborist world about how much concern cross loading a carabiner actually is. People can’t handle powerful falls anyways even if the gear does hold. It would be interesting to look at the green log chart to see how long a limb would have to be at 6” to get the loads in the video. Several guys use carabiners in rigging, which can easily see larger drop distances, all be it the tree dampens the force some while loading, and smaller limbs likely will have leaves to partially slow the fall too. I’ve only seen ropes break during rigging, not carabiners. Perhaps others could leave experiences which carabiners have broken during tree rigging.
