Ryan, Nice video, as always. A few comments . . . > As you showed, the rope breaking in the hanger is clearly not an issue. The main problems, as you also mentioned, are: 1) you could damage the rope in that one spot that's taking all the load, and 2), it could be really, really hard to pull down, especially as the jokers discovered near the end of the video if it's going through two hangers instead of one. There's a simple solution if you ever find yourself needing to lower off a hanger. Just take out a carabiner and leave it! Use a locker if you feel like it, or better yet, a cheapskate locker, with some athletic tape around the gate of a standard carabiner. Leave a $5 carabiner, and avoid even the slightest risk of damaging your $200 rope. Sheesh, I can't believe there's really any debate on this . . . > Metolius does not make those rounded rappel hangers anymore; at least, I can't find them on their website. You still may see them in the wild in a few places, especially at Smith Rock Oregon, but they are becoming increasingly rare. The story I heard as to why they were discontinued is that too many people were confusing them with regular hangers, and then trying to lower off standard hangers, and having issues with, guess what, rope damage and ropes getting stuck. They are also harder to replace when they get worn out than hardware installed with quick links.
There are still some Metolius rap hangers at Index and they are frustrating to use for both rappelling and clipping carabiners to (for building anchors). Lots of rope twisting, and some smaller carbiners can barely clip through them. I've seen some routes retrofitted with a couple quicklinks added to each hanger and while it defeats the purpose of using that hanger in the first place, it's way nicer to use for both anchors and rappelling. Good riddance, Metolius rap hangers.
This was my thought exactly. I'm in the research phase before I take my climbing outdoors and I've wondered what to do if I come to the top of the route and all that's provided are bolt anchors. My initial thought was just to carry a few extra $3 quick links to toss on the anchors and rappel off of. Leave $6 of equipment behind for the next climber instead of potentially damage my rope or risk injury from a rope failure.
@@FightingGravity2071 Quick links are a nice way to rappel from a 2-bolt anchor with only hangers, and it upgrades the anchor at the same time. However it's important that they are the same type of steel as the bolt hangers (usually stainless steel in most places in the states, but not always if the anchors are old). If uncertain, leaving a couple old carabiners is another great way, although it costs a little more than quicklinks, carabiners are lighter and you likely already have them with you so no need to carry extra quicklinks which are less useful otherwise while climbing.
@@FightingGravity2071 depending on the area and your style of climbing the more common scenario where you'll use this is when you dont make it to the anchor. e.g. the route was too hard or weather turned bad etc. for me it happens so rarely that it doesnt seem worth the effort of always carrying a quicklink on my harness
The reason one of the ropes broke much lower than the other two in the sharp hanger test (with 2 knots), is because the rope was moving over the hanger. THIS IS THE REASON YOU DON'T PUT YOUR ROPE ON SHARP STUFF! The force isn't the issue, the issue is movement over a sharp edge. You can try this out yourself if you don't mind cuts, as you can easily put quite a lot of pressure on a knife by just squeezing it, but the moment you pull the knife it will go right through your fingers. The same thing happens to the rope. Your tests were all very static apart from one (and even that one was quite static). Rappeling will make the rope move over the sharp edge and that's where it will definitely fail with a force way lower than in your tests. You could try bolting one end of the rope to the 'world' and the other to your hydraulic, that way it will put it over the sharp edge, and I think you'll get a lot lower numbers. To properly test it you'd want to put on a low force and move it about to find out how fast it fails.
Not a great analogy. Moving rope perpendicular to the sharp edge exposes new unadulterated material to the edge. However the knife analogy exposed the same, cuttable, material to a moving edge, henceforth cutting it further. Think of any type of saw with reciprocal or circular motion.
@@joshf-o6696 better to visualise it as a long diagonal cut. Once it breaks the outer sheath, suddenly it's cutting through the core, while the sheath bunches up around the outside.
The low force break at 5:45 feels like it is related to the rope slipping through the hanger. It would be really cool to see a series of tests where you simulate taking a whipper by allowing the dynamic rope to slide a bit due to the rope stretch. To do this, you could perhaps add a few zig-zags of rope through large radius pulleys so that the dynamic rope has more room to stretch and slip over the repel ring / bolt hanger. I’d love to have more data about rope strength when stretching and slipping over various sharp edges.
I agree, but there's an easy way to test this just by pulling on only 1 end of the 'U', with the other end tied to something static. The rope would then be forced to slide though the hanger while under tension.
Exactly the comment i was looking for!! I believe you are correct, i would love to see a test like this on the drop tower with the rope sliding through the hangers (in a whipper situation)
As a routesetter for my local climbing community in Oaxaca Mexico, this is some invaluable information. Its good to know that I was super safe enough, lowering off a hanger when i'd realized I ran out of quicklinks. I had used up the rest of my draws on the new bolts as I worked up the pitch, and didn't think to move a cam onto my nut/wire caribiner and use the coloured caribiner from the cam. Thanks for the useful info!
@@jmchich1 Near and in Oaxaca city the community is pretty lively and there are a couple gyms. I'm working on coastal cliff routes in Puerto Escondido. Its coming along nicely :)
Crucial distinction here - were you setting a rappel up on the hanger, or actually lowering off, which would mean the rope was actively feeding through the hanger - letting rope or slings slide under tension greatly increases risk for severing them. You mean you did not even have a single free carabiner to use?
Spitballing ahead: I think the static rope survived the hanger and broke in the knot because there's no rope-on-metal motion over the hanger at all, while the knot getting tighter and tighter gives a spot where rope-on-rope motion occurs. Also I suppose the resulting friction is always going to be concentrated on one spot, so even if it were able to move over the sharp hanger, the damage would still spread over a length of the rope instead of being concentrated in the knot. Goes to show just how much knots affect ropes, especially static ropes.
The low-strength rappel at 5:50 is interesting, as you can see the rope sliding across wearing it significantly before the break. I wonder how evenly I rappel down each strand, and whether I'd cause it to slide like that.
The word you are looking for is shear strength. A rope is designed for loads aligned in the direction of the rope (lengthwise), and thus its main application is for tensile strength. When you are loading the rope at the sharp hangers you are essentially relying on the shear strength of the rope. Each rope or material essentially has a maximum shear stress it will fail at. If you applied a constant load to the end of the rope and varied the bend radius, all you are essentially doing is varying the area on which that shear force is applied, and hence varying the stress. So for a constant load, the larger the bend radius, the larger the area is and hence the smaller the resultant stress on the rope. As for why the rope is failing at the knots, it is most likely due to the fact that, the knot itself is restricting the movement of fibers inside and not letting them slip, meaning each individual inner strand is taking varying loads and failing individually as apposed to if the whole bunch of fibers were loaded uniformly. From this I would also guess that a rope that does not have braided strands consisting of its inner core, would perform better in a knot test than one which has a braided core or which is entirely braided.
I think rope is too mailable to really fail in shear as you posit. Because the rope readily deforms at the kink, where the hanger is, I actually think rope is actually failing in tension at the outer edge of the radius. Need to rewatch the high speed footage, though to confirm this hypothesis.
Would love to see a video on the effectiveness of stopper knots whilst rapelling. A pull test with the knots getting sucked into an act or something of the sort. Great Video!
at 8:54, when you say: "when you pinch a rope and it's touching, it's damaged" I believe this has been disproven by Mammut in one of Hard is Easy videos. It is mainly the sheath that has been damaged or it's rigidity compromised, so that layer of protection has diminished, but not the core. Correct me if I'm wrong but I think that's what they said.
My personal preference: When you need to make a rappel in an emergency, it is fine to use a hanger. Better sacrifice a carabiner if possible. And maybe trow that rope away after rappelling several rope length through hangers.
For that nice rounded shackle break. 8:40 Yes there are two lines dividing the force in half, but isn't it 100% at the top of that shackle? Pulling half in each direction? So each leg is X, where they loop around the shackle X + X ? I find your videos really really instructive. Watching those knots start to slide, shows me why we're taught to tie one knot and not another, and why we leave tails and stoppers. With your videos this stuff is no longer abstract concepts; what can happen is real.
I love all of your fabricated enthusiasm (which I know is a facetiously dulled façade for genuine enthusiasm)! "Oh wow, look, it broke!" "Oh wow, it broke in the hanger!" And then there was, "are you a TH-cam engineer?!" to the girlfrannn. Love it.
The simple explanation of why the rope breaks in the knot more often than on the hanger is because the rope material is compromised by heat. As the knot cinches, it generates heat, as you have noted so many times in your videos, thereby reducing the strength of the rope in the knot. The real question is how a slow pull vs fast pull changes the heating profile and if it is enough to reliably change the outcome of these kinds of tests. The moral of the story is that if you are in an emergency and your rope is in good shape, you can rappel directly off the hanger...and save yourself the price of a carabiner. I Think I will still leave on behind, but still, nice to know I guess?
Ryan, a caveat. As mentioned at the end.. My only two concerns while climbing/rapping. 1) Rope retrieval when 35m of rope is hanging off a hanger is basically impossible. 2) Rope abrasion over time (if you actually happen to retrieve your rope in this fashion) Great informative video for those who don’t know 👍
Question: looks like it's "super strong enough" for rappelling down, even if not ideal, and the bigger issue is pulling the rope down when you finish, or wearing the rope out quickly if you do it often. Assuming you are able to pull it down, is doing this any worse for the rope than climbing on toprope when the anchor is over a ledge and makes the rope drag over an edge of the rock?
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Nice test. Thanks for breaking thing for us. To complete this serie, I'm wondering what happens if you protect the rope with some chip matérials like duck tape, rubber band, garden hose, electric sheath.
"That sounded a lot louder than a 22 (kn)" I love that you've done this so much that you've developed an ear for what breaks and their corresponding measurements should be.
I believe 'Alpine Caving Techniques' describes a lightweight caving technique where the Petzl aluminium hangers are threaded onto the rope and tied into the belays (Mid rope knots). Never trusted it myself, always used Maillion's or krabs. I always knew it wouldn't have been that daft but nice to see it statically tested. Now if someone is prusicking up the rope threaded through a sharp hanger...
A long time ago when cleaning up an anchor at Birdsboro Rock Quarry in PA, I noticed there wasn't any rappel rings or mussy hooks so I had no other option than to run the rope through the anchor hangers and rappel off of it. I knew it probably wasn't the best for the rope, but I had no other options. I don't recommend doing this.
Had the same problem with a climber feeding the rope through the hangers when it had quick links on it. but i think he was smarter & didn't do it again. I hate telling noob climbers "reasons why" to do things this way or that way, just to have them completely ignore the advice you just gave them that could save their life.... Ran into another pair of young dudes at the crag who told me they learned all their climbing knowledge strictly off of youtube. The one kid was using a sling for his personal anchor (normal) but he had it attached to his belay loop with two wires gates (opposite & opposed (thank god for that)) and then just one wire gate at the end to go direct. I told him that was a good way to end up dead (especially since I was watching how he kept pulling up on his personal anchor while cleaning an anchor before I saw his setup). I then advised him to girth hitch either both leg/waist loops or the belay loop with the pros/cons of each & to use a locker for going direct and showed him how to do it! The next day our group was making breakfast, these two geared up to hit crag, and I looked at the one kid who I just gave the advice to and he rigged up his personal anchor the exact same way he had it before I gave him the life saving advice. I just shook my head, some people just need to earn their Darwin awards.
I think a big difference between climbing and other sports is that the common process of buying the gear and just going out and trying the thing is not typically a life-or-death trial-and-error process with other sports. Climbing (and other gravity sports too, like skiing) have a waaay higher risk of injury as a novice if you just send it without instruction, but it seems like some people don't understand or appreciate that difference. Not saying everyone needs to hire a guide to try a new sport, but way more so in climbing you might actually end up dead on day 1 if you just wing it.
As a TH-cam engineer, who knows all the answers after I see the result, I'd like to repeat my comment from the last video- if you can't cut your finger on an edge, that's not the sort of "sharp edge" you need to avoid having your rope run over.
I actually wanted to see one end of the rope anchored in and the other end stretched with the machine, in that case it would simulate the repelling situation better I think
Hi, first of all, thanks for the valuable info you guys upload. So, I wonder why you didnt test the Mad Rock Sentinel hanger, which has a rounded edge different than the ones you tested. Finally, where in the US can I buy the "Duplas"? Regards
I didn’t know mad rock made a similar thing. They are almost identical to Bonier Pingos we tested in this video. Link is in bio for Bonier, just email them and see if they can send the duplas to the states.
I would love to see some overhand knots pulled against quicklinks/chain link, like in a single rope rappel with a tagline configuration. Think about using it as a backup and curious what that would break at.
Would also love to see a test on a series of ropes that have been progressively more loaded over a sharp hanger, and then broken straight. As the rope gets more core-shot, does it eventually start breaking at the bent point? How much weight does a rope need to take over a sharp hanger before it stops performing well.
Does anyone know if it is safe to rappel down a bolt hold? Uses is to get my quick draw without using a bailer biner, any advice is appreciated, thank you!
I've never been worried about my rope failing through a bolt, it's dragging it through then using it. Can you test the life of the rope when dragging it through the bolt vs ring/biner?
Willing to bet a ham sandwich that those folks looped through the hangers not the loops because they didn't trust the quick links. I would trust the quick links because they're steel and strong, but they are sold as hardware store items, typically, and usually say "not for overhead lifting". Very curious to see if you guys have tested them. Love the "engineering experts AFTER the tests have been done"!
I'd like to understand the damage caused by pulling the rope through the hanger after you're done rappelling. I think that this is more likely to cause damage than just lowering. If you do decide to test this, please weight the rope to simulate the rope drag. 100 pulls through the hange should show significant wear.
My apologies if I missed anything, but from watching many of your videos, I still don’t know what’s the strongest loop knot (fixed and non fixed loop).
it looks like the sharp hanger will have the rope fail at a lower KN if there is a bit over movement instead of the rope pulling exactly even on both side the one low fail seemed to have a bit of a sawing motion vs the others where the rope stayed completely still while being pulled
I wonder if some of the reason for break strength increasing in successive tests on the same hanger is from the hanger being smoothed out or changing shape to be slightly nicer to the rope after a couple of tests.
Anyway you could test some knots normally used for fishing, specifically a uni or double uni knot. I'm genuinely curious how it would do as the non tag end doesn't bend at all on it's way through the knot
I would love to see some wear tests, with a spliced rope loop and a pulley with a piece of gear at the end to test the longevity of things like carabiners, hangers, belay devices and other equipment. Don’t know if the setup would be worth it but I would love to see so tests of that
Thanks for this video! Could you simulate what can happen if somebody tries to come down from top using the rope passing through stuff from this video?
I always wondered why the most common hanger design had such “sharp” edges (relative to being rounded over even if only slightly); guessing just cheaper to stamp them out? I once thought I’d get burrs in my gear from these hangers but honestly haven’t really seen that and don’t worry about it. Def would not put soft materials through them though!
Some hanger brands like Fixe have started rounding the edges of their newer hangers more so they aren't as sharp, which should help reduce aluminum carabiners getting chewed up. But yes a lot of older generation hangers were pretty basic stamped and bend with only a very light edge debur process, not a true radius added to them.
Can you simulate cyclic loading to 4kn, and see how long before it fails? That'll simulate a rope that's always used to bail off mid-climb directly on hanger.
but isn't sharp edge suppose to cut into the rope as the rope gets pull through repeatedly? in your experiment it does show flatten rope which is a sign of core rope damage
So I guess the scenario is needing to bail off a route without leaving your bail 'biner or shackle behind or mess about with a sling? You can minimise the radius /bend obver the edge by feeding half the rope through and tying an overhand on the bight ( or if joining ropes two ropes your usual offset overhand bend with long tails) on the inside bolt side of the hanger. The hanger tends to sit into the V formed by the two ropes
I'd love to see a dynamic climbing rope pulled to two Kn and left at that tension for two minutes or whatever time. I've seen people bail by doing a double strand rappel on a single hanger rather than leave a bail biner. Curious if keeping the rope at those low forces noticably damages the rope, obviously it wouldn't cut, but I'd like to see if the core softens up seriously after that... I was sharing a rope with some friends when they asked if they could bail like that on my rope, told them no and I'm curious if it's as bad as I assumed on a rope.
Hey Ryan, I was once out of route and I found two horizontal hangers (without repel rings) and I had to use them to repel down. My main concerns were the triangular shape of the rope (created by the 2 hangers and the ATC) and then if the hangers were sharp Would you consider it "super good enough?" Did you have ever tested something similar?
I havent climbed for years but I find your videos fascinating. What is odd is how certain things are far more dangerous than I realised, and how other things are much safer than people claim.
Test Idea: How fast and far would a person need to descend before a rope melts while rappelling, when the person comes to a stop, while still on the rope? I would be interested to see Figure of 8s Vs Rappel Racks, and the difference between stainless steel and aluminium.
I think this topic would beter be tested on the drop tower because as you are demonstrating the slow pull strength is usually super good enough but abrasion seems to be more of a factor than strength when climbing
When testing rappel strengths, why not put an ATC or reverso on the pull side? We're seeing knot vs bend radius, but when rappelling I'm not on a knot im on an ATC. Perhaps the rope would slip through the rap device before it ever broke? Then would make sense to use knots instead because the goal is a break. Either way, would love to see a test in which you pull on an ATC loaded on a rap setup! Get in touch maybe I'll send you some gear to test Also, *radii
What happens if you pull one of the two legs while the other is tied off to a static point, the slight pull across while under high tension might change things and is probably more accurate to real life loads.
I had to rap off two of the beefier hangers the other week and was wondering how unsafe, if at all, it was. My thoughts were that the hangers had no sharp edges or burs and were about as thick as a caribiner 🤷♂️
At 5:44 you can see the rope slipping slightly over the sharp edge. The edge cuts the rope. If the rope is knotted, this does not happen as easily as with two different knots or, for example, abseiling on both strands. I would not do that!
It's half the force on the rope because there are 2 ropes going to the sharp egdge hanger . When the rope enters the knot with every bend the force gets lower.
So . . .. there might be gains in anchoring a smaller diameter rope around a pulley . If the intent is to utilize the rope more fully such as in a recuse situation. Not so much as an everyday situation but rather you're improvising. Might also be some minimal gains in lower friction from a pulley instead of immobile bare metal.
Way good for sport safety. need to test fast action - dynamic strain is time mediated - if only there was a drop tower.... Though the engineer in me would have expected more fracture at the sharp haanger.... Wear over time too is a concern as you addressed.
That was a lot stronger than I expected. Additionnaly if you are threading the rope through two ancor plates that are at the same level (like on the thumbnail picture) the angles are even wider so should be even stronger.
10:30 the people who did that think the chains and anchor rings just means extra points of failure, and took advantage of that guys kindness at the detriment of their gears lifespan and safety factors (edge diameters). To summarize: Hard headed.
Just watched this video and would like to comment on the test method. It did indeed seem surprising that the rope would break at the knot rather than over a sharp edge sometimes. When the rope breaks at the knot at for example 14kN, that is the tension in the rope at that point. But because the rope is tied in a loop to attach to the hanger, the tension in the rope going to the hanger is only half on each side, ie 7kN. It seems to me this explains why the rope is not consistently getting cut at the hanger edge. You can see this visually in the video, the rope below the knot gets stretched super thin but the rope in the loop stays fatter. If you were to belay through the hanger (not recommended) then there is no loop to divide the tension in half so the tension at the hanger will be very close to the tension at your tie in knot. If you set the test up like this I think you would find the rope cut at the hanger every time. I think the video makes it seem like knots are worse than the hanger edge but I don’t believe that is the case if the test was done differently. Welcome comments. Am I missing something?
Ryan, Nice video, as always. A few comments . . .
> As you showed, the rope breaking in the hanger is clearly not an issue. The main problems, as you also mentioned, are: 1) you could damage the rope in that one spot that's taking all the load, and 2), it could be really, really hard to pull down, especially as the jokers discovered near the end of the video if it's going through two hangers instead of one.
There's a simple solution if you ever find yourself needing to lower off a hanger. Just take out a carabiner and leave it! Use a locker if you feel like it, or better yet, a cheapskate locker, with some athletic tape around the gate of a standard carabiner. Leave a $5 carabiner, and avoid even the slightest risk of damaging your $200 rope. Sheesh, I can't believe there's really any debate on this . . .
> Metolius does not make those rounded rappel hangers anymore; at least, I can't find them on their website. You still may see them in the wild in a few places, especially at Smith Rock Oregon, but they are becoming increasingly rare.
The story I heard as to why they were discontinued is that too many people were confusing them with regular hangers, and then trying to lower off standard hangers, and having issues with, guess what, rope damage and ropes getting stuck. They are also harder to replace when they get worn out than hardware installed with quick links.
There are still some Metolius rap hangers at Index and they are frustrating to use for both rappelling and clipping carabiners to (for building anchors). Lots of rope twisting, and some smaller carbiners can barely clip through them. I've seen some routes retrofitted with a couple quicklinks added to each hanger and while it defeats the purpose of using that hanger in the first place, it's way nicer to use for both anchors and rappelling. Good riddance, Metolius rap hangers.
This was my thought exactly. I'm in the research phase before I take my climbing outdoors and I've wondered what to do if I come to the top of the route and all that's provided are bolt anchors. My initial thought was just to carry a few extra $3 quick links to toss on the anchors and rappel off of. Leave $6 of equipment behind for the next climber instead of potentially damage my rope or risk injury from a rope failure.
@@FightingGravity2071 Quick links are a nice way to rappel from a 2-bolt anchor with only hangers, and it upgrades the anchor at the same time. However it's important that they are the same type of steel as the bolt hangers (usually stainless steel in most places in the states, but not always if the anchors are old). If uncertain, leaving a couple old carabiners is another great way, although it costs a little more than quicklinks, carabiners are lighter and you likely already have them with you so no need to carry extra quicklinks which are less useful otherwise while climbing.
@@Govanification great info! Thanks for the reply!
@@FightingGravity2071 depending on the area and your style of climbing the more common scenario where you'll use this is when you dont make it to the anchor. e.g. the route was too hard or weather turned bad etc. for me it happens so rarely that it doesnt seem worth the effort of always carrying a quicklink on my harness
The reason one of the ropes broke much lower than the other two in the sharp hanger test (with 2 knots), is because the rope was moving over the hanger. THIS IS THE REASON YOU DON'T PUT YOUR ROPE ON SHARP STUFF! The force isn't the issue, the issue is movement over a sharp edge. You can try this out yourself if you don't mind cuts, as you can easily put quite a lot of pressure on a knife by just squeezing it, but the moment you pull the knife it will go right through your fingers. The same thing happens to the rope. Your tests were all very static apart from one (and even that one was quite static). Rappeling will make the rope move over the sharp edge and that's where it will definitely fail with a force way lower than in your tests.
You could try bolting one end of the rope to the 'world' and the other to your hydraulic, that way it will put it over the sharp edge, and I think you'll get a lot lower numbers. To properly test it you'd want to put on a low force and move it about to find out how fast it fails.
Not to mention you will be repeatedly using the (roughly) the same middle of your rope if you do several abseils.
Not a great analogy. Moving rope perpendicular to the sharp edge exposes new unadulterated material to the edge. However the knife analogy exposed the same, cuttable, material to a moving edge, henceforth cutting it further. Think of any type of saw with reciprocal or circular motion.
@@joshf-o6696 better to visualise it as a long diagonal cut. Once it breaks the outer sheath, suddenly it's cutting through the core, while the sheath bunches up around the outside.
It's not like pulling a knife over your fingers. It is like pulling your fingers over a knife, sideways. Completely different results.
Classic "Super Good Enough" at 5x safety rating, but i think ill still go through the rap ring unless im under duress lol.
These videos really are super good enough. Thanks for the excellent follow-up to the Texas Rope Trick.
The low force break at 5:45 feels like it is related to the rope slipping through the hanger. It would be really cool to see a series of tests where you simulate taking a whipper by allowing the dynamic rope to slide a bit due to the rope stretch. To do this, you could perhaps add a few zig-zags of rope through large radius pulleys so that the dynamic rope has more room to stretch and slip over the repel ring / bolt hanger. I’d love to have more data about rope strength when stretching and slipping over various sharp edges.
I agree, but there's an easy way to test this just by pulling on only 1 end of the 'U', with the other end tied to something static. The rope would then be forced to slide though the hanger while under tension.
Indeed the length it will run at that point doesn't depend on the rope length. For a given pulling force, elongation will be x mm each meter.
Exactly the comment i was looking for!! I believe you are correct, i would love to see a test like this on the drop tower with the rope sliding through the hangers (in a whipper situation)
Hi!
Also, they have the drop tower for this
As a routesetter for my local climbing community in Oaxaca Mexico, this is some invaluable information. Its good to know that I was super safe enough, lowering off a hanger when i'd realized I ran out of quicklinks. I had used up the rest of my draws on the new bolts as I worked up the pitch, and didn't think to move a cam onto my nut/wire caribiner and use the coloured caribiner from the cam.
Thanks for the useful info!
I visited Oaxaca a while ago (before I got into climbing) and loved it. What's the local scene like? I'd love to come back again some day!
@@jmchich1 Near and in Oaxaca city the community is pretty lively and there are a couple gyms. I'm working on coastal cliff routes in Puerto Escondido. Its coming along nicely :)
Crucial distinction here - were you setting a rappel up on the hanger, or actually lowering off, which would mean the rope was actively feeding through the hanger - letting rope or slings slide under tension greatly increases risk for severing them. You mean you did not even have a single free carabiner to use?
@@z1522 rappelled down just one bolt and lowered off the draw on the bolt below, collecting pro. got the draw the next day.
Thanks
Spitballing ahead: I think the static rope survived the hanger and broke in the knot because there's no rope-on-metal motion over the hanger at all, while the knot getting tighter and tighter gives a spot where rope-on-rope motion occurs. Also I suppose the resulting friction is always going to be concentrated on one spot, so even if it were able to move over the sharp hanger, the damage would still spread over a length of the rope instead of being concentrated in the knot. Goes to show just how much knots affect ropes, especially static ropes.
The low-strength rappel at 5:50 is interesting, as you can see the rope sliding across wearing it significantly before the break. I wonder how evenly I rappel down each strand, and whether I'd cause it to slide like that.
The word you are looking for is shear strength. A rope is designed for loads aligned in the direction of the rope (lengthwise), and thus its main application is for tensile strength. When you are loading the rope at the sharp hangers you are essentially relying on the shear strength of the rope. Each rope or material essentially has a maximum shear stress it will fail at. If you applied a constant load to the end of the rope and varied the bend radius, all you are essentially doing is varying the area on which that shear force is applied, and hence varying the stress. So for a constant load, the larger the bend radius, the larger the area is and hence the smaller the resultant stress on the rope.
As for why the rope is failing at the knots, it is most likely due to the fact that, the knot itself is restricting the movement of fibers inside and not letting them slip, meaning each individual inner strand is taking varying loads and failing individually as apposed to if the whole bunch of fibers were loaded uniformly. From this I would also guess that a rope that does not have braided strands consisting of its inner core, would perform better in a knot test than one which has a braided core or which is entirely braided.
I think rope is too mailable to really fail in shear as you posit. Because the rope readily deforms at the kink, where the hanger is, I actually think rope is actually failing in tension at the outer edge of the radius.
Need to rewatch the high speed footage, though to confirm this hypothesis.
Would love to see a video on the effectiveness of stopper knots whilst rapelling. A pull test with the knots getting sucked into an act or something of the sort. Great Video!
at 8:54, when you say: "when you pinch a rope and it's touching, it's damaged"
I believe this has been disproven by Mammut in one of Hard is Easy videos. It is mainly the sheath that has been damaged or it's rigidity compromised, so that layer of protection has diminished, but not the core.
Correct me if I'm wrong but I think that's what they said.
This stuff never gets old, thank you for pulling back the curtain!
WOW... WOW... I really expected to see strengths of 5KN or just maybe 7KN or something for rope through a hangar. I had no idea!!! Thank you
My personal preference: When you need to make a rappel in an emergency, it is fine to use a hanger. Better sacrifice a carabiner if possible. And maybe trow that rope away after rappelling several rope length through hangers.
For that nice rounded shackle break. 8:40 Yes there are two lines dividing the force in half, but isn't it 100% at the top of that shackle? Pulling half in each direction? So each leg is X, where they loop around the shackle X + X ?
I find your videos really really instructive. Watching those knots start to slide, shows me why we're taught to tie one knot and not another, and why we leave tails and stoppers. With your videos this stuff is no longer abstract concepts; what can happen is real.
would be interesting to see these test repeated with thinner static ropes used directly in anchors, like 5,5 to 7mm cordelette of kevlar and dyneema
I love all of your fabricated enthusiasm (which I know is a facetiously dulled façade for genuine enthusiasm)! "Oh wow, look, it broke!" "Oh wow, it broke in the hanger!" And then there was, "are you a TH-cam engineer?!" to the girlfrannn. Love it.
I'm stealing that phrase: "fabricated enthusiasm."
@@user-pr5tx9ep4m Haha, I'm glad you like it. Put it to good use and let's start a new trend!
The simple explanation of why the rope breaks in the knot more often than on the hanger is because the rope material is compromised by heat. As the knot cinches, it generates heat, as you have noted so many times in your videos, thereby reducing the strength of the rope in the knot. The real question is how a slow pull vs fast pull changes the heating profile and if it is enough to reliably change the outcome of these kinds of tests.
The moral of the story is that if you are in an emergency and your rope is in good shape, you can rappel directly off the hanger...and save yourself the price of a carabiner. I Think I will still leave on behind, but still, nice to know I guess?
Reading the comments pays of as I was about to type a similar one regarding the build up of temperature in the knots
Ryan, a caveat. As mentioned at the end.. My only two concerns while climbing/rapping. 1) Rope retrieval when 35m of rope is hanging off a hanger is basically impossible. 2) Rope abrasion over time (if you actually happen to retrieve your rope in this fashion)
Great informative video for those who don’t know 👍
Worse than rope abrasion is the wear to the fixed hanger!
Don't worry @@ionstorm66 ! There will be no rope abrasion, because you won't be able to pull the rope an inch!
I did this and for rappelling when you bail out it’s super good enough!
Question: looks like it's "super strong enough" for rappelling down, even if not ideal, and the bigger issue is pulling the rope down when you finish, or wearing the rope out quickly if you do it often. Assuming you are able to pull it down, is doing this any worse for the rope than climbing on toprope when the anchor is over a ledge and makes the rope drag over an edge of the rock?
YES happy to see this video come through!!!
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Nice test. Thanks for breaking thing for us.
To complete this serie, I'm wondering what happens if you protect the rope with some chip matérials like duck tape, rubber band, garden hose, electric sheath.
Can you please do a test on the strength of a double bowline with a follow through?
"That sounded a lot louder than a 22 (kn)"
I love that you've done this so much that you've developed an ear for what breaks and their corresponding measurements should be.
I believe 'Alpine Caving Techniques' describes a lightweight caving technique where the Petzl aluminium hangers are threaded onto the rope and tied into the belays (Mid rope knots).
Never trusted it myself, always used Maillion's or krabs. I always knew it wouldn't have been that daft but nice to see it statically tested.
Now if someone is prusicking up the rope threaded through a sharp hanger...
A long time ago when cleaning up an anchor at Birdsboro Rock Quarry in PA, I noticed there wasn't any rappel rings or mussy hooks so I had no other option than to run the rope through the anchor hangers and rappel off of it. I knew it probably wasn't the best for the rope, but I had no other options. I don't recommend doing this.
Had the same problem with a climber feeding the rope through the hangers when it had quick links on it. but i think he was smarter & didn't do it again.
I hate telling noob climbers "reasons why" to do things this way or that way, just to have them completely ignore the advice you just gave them that could save their life....
Ran into another pair of young dudes at the crag who told me they learned all their climbing knowledge strictly off of youtube. The one kid was using a sling for his personal anchor (normal) but he had it attached to his belay loop with two wires gates (opposite & opposed (thank god for that)) and then just one wire gate at the end to go direct. I told him that was a good way to end up dead (especially since I was watching how he kept pulling up on his personal anchor while cleaning an anchor before I saw his setup). I then advised him to girth hitch either both leg/waist loops or the belay loop with the pros/cons of each & to use a locker for going direct and showed him how to do it! The next day our group was making breakfast, these two geared up to hit crag, and I looked at the one kid who I just gave the advice to and he rigged up his personal anchor the exact same way he had it before I gave him the life saving advice. I just shook my head, some people just need to earn their Darwin awards.
I think a big difference between climbing and other sports is that the common process of buying the gear and just going out and trying the thing is not typically a life-or-death trial-and-error process with other sports. Climbing (and other gravity sports too, like skiing) have a waaay higher risk of injury as a novice if you just send it without instruction, but it seems like some people don't understand or appreciate that difference. Not saying everyone needs to hire a guide to try a new sport, but way more so in climbing you might actually end up dead on day 1 if you just wing it.
As a TH-cam engineer, who knows all the answers after I see the result, I'd like to repeat my comment from the last video- if you can't cut your finger on an edge, that's not the sort of "sharp edge" you need to avoid having your rope run over.
Looks like you don't know the answer after seeing the result. :-)
I actually wanted to see one end of the rope anchored in and the other end stretched with the machine, in that case it would simulate the repelling situation better I think
Hi, first of all, thanks for the valuable info you guys upload.
So, I wonder why you didnt test the Mad Rock Sentinel hanger, which has a rounded edge different than the ones you tested.
Finally, where in the US can I buy the "Duplas"?
Regards
I didn’t know mad rock made a similar thing. They are almost identical to Bonier Pingos we tested in this video. Link is in bio for Bonier, just email them and see if they can send the duplas to the states.
I would love to see some overhand knots pulled against quicklinks/chain link, like in a single rope rappel with a tagline configuration. Think about using it as a backup and curious what that would break at.
What about attaching rope to the side of a QuickDraw that’s worn down from bolts?
Would also love to see a test on a series of ropes that have been progressively more loaded over a sharp hanger, and then broken straight. As the rope gets more core-shot, does it eventually start breaking at the bent point? How much weight does a rope need to take over a sharp hanger before it stops performing well.
Does anyone know if it is safe to rappel down a bolt hold? Uses is to get my quick draw without using a bailer biner, any advice is appreciated, thank you!
Have you done splice vrs knot? Can you even splice climbing ropes?
Bowline vrs figure 8?
I've never been worried about my rope failing through a bolt, it's dragging it through then using it. Can you test the life of the rope when dragging it through the bolt vs ring/biner?
That sponsorship transition was down right impressive.
Willing to bet a ham sandwich that those folks looped through the hangers not the loops because they didn't trust the quick links. I would trust the quick links because they're steel and strong, but they are sold as hardware store items, typically, and usually say "not for overhead lifting". Very curious to see if you guys have tested them. Love the "engineering experts AFTER the tests have been done"!
I'd like to understand the damage caused by pulling the rope through the hanger after you're done rappelling. I think that this is more likely to cause damage than just lowering. If you do decide to test this, please weight the rope to simulate the rope drag. 100 pulls through the hange should show significant wear.
My apologies if I missed anything, but from watching many of your videos, I still don’t know what’s the strongest loop knot (fixed and non fixed loop).
it looks like the sharp hanger will have the rope fail at a lower KN if there is a bit over movement instead of the rope pulling exactly even on both side the one low fail seemed to have a bit of a sawing motion vs the others where the rope stayed completely still while being pulled
I wonder if some of the reason for break strength increasing in successive tests on the same hanger is from the hanger being smoothed out or changing shape to be slightly nicer to the rope after a couple of tests.
Anyway you could test some knots normally used for fishing, specifically a uni or double uni knot. I'm genuinely curious how it would do as the non tag end doesn't bend at all on it's way through the knot
I would love to see some wear tests, with a spliced rope loop and a pulley with a piece of gear at the end to test the longevity of things like carabiners, hangers, belay devices and other equipment. Don’t know if the setup would be worth it but I would love to see so tests of that
Thanks for this video! Could you simulate what can happen if somebody tries to come down from top using the rope passing through stuff from this video?
I always wondered why the most common hanger design had such “sharp” edges (relative to being rounded over even if only slightly); guessing just cheaper to stamp them out? I once thought I’d get burrs in my gear from these hangers but honestly haven’t really seen that and don’t worry about it. Def would not put soft materials through them though!
You do get burrs in aluminium carabiners. That’s one of the reason why you always use one side of quickdraws for the bolt and the other for the rope.
Some hanger brands like Fixe have started rounding the edges of their newer hangers more so they aren't as sharp, which should help reduce aluminum carabiners getting chewed up. But yes a lot of older generation hangers were pretty basic stamped and bend with only a very light edge debur process, not a true radius added to them.
Can you simulate cyclic loading to 4kn, and see how long before it fails? That'll simulate a rope that's always used to bail off mid-climb directly on hanger.
If you're lowering you most likely will not fall on the hanger. Wouldn't the issue be more that the rope is sliding through the sharp'ish hanger?
but isn't sharp edge suppose to cut into the rope as the rope gets pull through repeatedly? in your experiment it does show flatten rope which is a sign of core rope damage
So I guess the scenario is needing to bail off a route without leaving your bail 'biner or shackle behind or mess about with a sling? You can minimise the radius /bend obver the edge by feeding half the rope through and tying an overhand on the bight ( or if joining ropes two ropes your usual offset overhand bend with long tails) on the inside bolt side of the hanger. The hanger tends to sit into the V formed by the two ropes
I have. It can twist the rope horribly spiralling it to a pig tail so I won't do it again. Also, hard to pull down.
How come the rope breaks at only about 14kN max when you fig 8 to fig 8 ?
So, are your saying it's relatively safe to abseil off a hanger? Would you do that?
I'd love to see a dynamic climbing rope pulled to two Kn and left at that tension for two minutes or whatever time. I've seen people bail by doing a double strand rappel on a single hanger rather than leave a bail biner. Curious if keeping the rope at those low forces noticably damages the rope, obviously it wouldn't cut, but I'd like to see if the core softens up seriously after that... I was sharing a rope with some friends when they asked if they could bail like that on my rope, told them no and I'm curious if it's as bad as I assumed on a rope.
Hey Ryan, I was once out of route and I found two horizontal hangers (without repel rings) and I had to use them to repel down.
My main concerns were the triangular shape of the rope (created by the 2 hangers and the ATC) and then if the hangers were sharp
Would you consider it "super good enough?" Did you have ever tested something similar?
Check out our video on the American Death Triangle.
I havent climbed for years but I find your videos fascinating.
What is odd is how certain things are far more dangerous than I realised, and how other things are much safer than people claim.
Now you guys are going to have to test knots. I like the figure eight on a byte with a half barrel knot on the rope for no reason :)
Test Idea: How fast and far would a person need to descend before a rope melts while rappelling, when the person comes to a stop, while still on the rope?
I would be interested to see Figure of 8s Vs Rappel Racks, and the difference between stainless steel and aluminium.
Interested to see what a dynamic fall onto the hanger would do
What about wet ropes Ryan? Same tests, what do you expect here?
BONIER is the best name ever
I think this topic would beter be tested on the drop tower because as you are demonstrating the slow pull strength is usually super good enough but abrasion seems to be more of a factor than strength when climbing
When testing rappel strengths, why not put an ATC or reverso on the pull side? We're seeing knot vs bend radius, but when rappelling I'm not on a knot im on an ATC.
Perhaps the rope would slip through the rap device before it ever broke? Then would make sense to use knots instead because the goal is a break. Either way, would love to see a test in which you pull on an ATC loaded on a rap setup! Get in touch maybe I'll send you some gear to test
Also, *radii
What happens if you pull one of the two legs while the other is tied off to a static point, the slight pull across while under high tension might change things and is probably more accurate to real life loads.
I had to rap off two of the beefier hangers the other week and was wondering how unsafe, if at all, it was. My thoughts were that the hangers had no sharp edges or burs and were about as thick as a caribiner 🤷♂️
Why didn't you use the drop tower for this test? It would have been better info to see.
Bonnier, congrats!!!!!
At 5:44 you can see the rope slipping slightly over the sharp edge. The edge cuts the rope. If the rope is knotted, this does not happen as easily as with two different knots or, for example, abseiling on both strands. I would not do that!
Excellent testing demonstrations.
Destructive testing at its Best.
I'd think it would probably make a rope wear out faster in those sharper hangers with repetitive use but who knows
Would be interested to see the petal clown a different pull angles
Have you guys ever break tested eyelets?
It's half the force on the rope because there are 2 ropes going to the sharp egdge hanger . When the rope enters the knot with every bend the force gets lower.
What if you lowered off it and increased the weight over tests? Maybe a cool opportunity to use the tower!
I use pingo to make easy the rapel. You must use two to avoid contact to sharp edges and make easy to recover the rope.
So . . .. there might be gains in anchoring a smaller diameter rope around a pulley . If the intent is to utilize the rope more fully such as in a recuse situation. Not so much as an everyday situation but rather you're improvising. Might also be some minimal gains in lower friction from a pulley instead of immobile bare metal.
Ngl I’ve done this more than a few times on routes without rings, seems super good enough if the hangers aren’t insanely sharp
Way good for sport safety.
need to test fast action - dynamic strain is time mediated - if only there was a drop tower.... Though the engineer in me would have expected more fracture at the sharp haanger.... Wear over time too is a concern as you addressed.
There is no scenario where people put ropes in hangers and then shock load it, so we didn’t use drop tower.
@@HowNOT2 . Cool, so static only.
Why isn’t splicing used in rock climbing way more if it’s that much stronger?
I love these vids!
But can you untie the crushed double 8 knots?!?
That was a lot stronger than I expected. Additionnaly if you are threading the rope through two ancor plates that are at the same level (like on the thumbnail picture) the angles are even wider so should be even stronger.
Ty!
Very informative. Nice
Seems like those figure 8s aren't properly dressed? I may be wrong but it's worth a look
hey wheres the new slack snap?
10:30 the people who did that think the chains and anchor rings just means extra points of failure, and took advantage of that guys kindness at the detriment of their gears lifespan and safety factors (edge diameters). To summarize: Hard headed.
Yeah after seeing this im totally good with rappelling off a hanger alone if it came to it.
0:40 - The neighbor engaging in some lite rent control.
Canyoneer here, completely surprised by this
if you need to rappel from hanger, just use maillon, it's cheapest
I tried pausing the video. Before you explained it. I'm just kidding I almost did though which is why the joke landed so hard over here in Montana lol
Just watched this video and would like to comment on the test method. It did indeed seem surprising that the rope would break at the knot rather than over a sharp edge sometimes. When the rope breaks at the knot at for example 14kN, that is the tension in the rope at that point. But because the rope is tied in a loop to attach to the hanger, the tension in the rope going to the hanger is only half on each side, ie 7kN. It seems to me this explains why the rope is not consistently getting cut at the hanger edge. You can see this visually in the video, the rope below the knot gets stretched super thin but the rope in the loop stays fatter.
If you were to belay through the hanger (not recommended) then there is no loop to divide the tension in half so the tension at the hanger will be very close to the tension at your tie in knot. If you set the test up like this I think you would find the rope cut at the hanger every time.
I think the video makes it seem like knots are worse than the hanger edge but I don’t believe that is the case if the test was done differently.
Welcome comments. Am I missing something?
Your channel rules. I use your plaster and painting tips all the time.
Interesting AF I don’t even climb.. I’m tripping that the carabiner held up😳
I don't really care about climbing, but i do love testing stuff.
Nice video!