Why The Overkill?
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- Опубликовано: 14 мар 2023
- Whoopie slings are spliced adjustable slings but Samson's instructions say that the bury has to be so long for the adjustable eye that it's almost unusable. For our 1/4" or 6mm Amsteel Blue sk75 Dyneema, that is a minimum of 3 feet long. Of course, it can be as big as you are willing to make the tail.
We wanted to test if you can get away with smaller bury lengths and also the strength a whoopie loses because it doesn't have a gentle taper, but abruptly comes out of the side. Samson says you can expect 70% of the average breaking strength which is believable but it is sure fun to test it anyways.
Our blog has the data: www.hownot2.com/post/whoopies...
Jarod Lojeck can make custom dyneema products for you: SpliceOfLifeCT@gmail.com
Samson's Instructions www.samsonrope.com/docs/defau...
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Why should the bury be so long?
01:08 What we are testing
02:59 Whoopies Tested
05:42 Eye to eye control tests
07:35 Soft shackle whoopies
09:12 Conclusions
11:47 Metric Police
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Thank you for testing the soft shackle whoopies. I hope my samples bring about an informative conversation.
Thank you very much for working with this awesome channel! It's very informative!
? Did you set the samples?
What was the taper rate?
Eg strands cut/ separation of cuts.
My preference is what Samson shows on pg 69 step 2 in there book" Slicing Manual " . With a change.
I also taper the last 6 in pairs ( 2extra pairs cut evenly spaced ) leaving only 2strands at the end .
I see this as reducing the sharpness of the taper.
I have pulled 5/16 sk78 woopie to failure ( broke where the tail comes out same as this test not in the taper of the fixed end). I was pulling out volunteer aspen trees, with an 8-ton come-a- long and hi-lift jack .out of flower beds roots and all that would come under the fence.
3 thoughts about reasons for long bury.
The tapered part is less effectively cault. In the finger trap.
1 fid is used up in the taper, making a 1 fid barrie ineffective due to only pulling on have the strands .
@@daviddroescher I set the samples under body weight, and arm strength pulls, but did not have any mechanical devices to assist.
I tapered with a 6 strand taper in opposing pairs. I tapered at a 1/2 fid length in even progression.
@@daviddroescher with regards to bury length, none of the Brummel eyes slipped. Breaking at the tip of the taper is common when eye bend radius is good, and the splice holds. Soft goods are just variable. I did not make the lengths to manual specs because highliners don't for the most part. None of the Brummel eyes failed. The constrictor lengths of 1, 1.5, and 2 fids were at Ryan's request since, again, most highliners don't follow the manual in order to have more workable minimum lengths.
I wonder if the results would improve if the whoopie tail where reburied near the place soft shackle penetrates the single strand creating coaxial strands. Pass the rope through both coaxial strands. The tail would no longer hang loose, but be an adjustment loop. Which provides backup strength in case the shorter whoopie section slips. Multiple very short whoopie loops in a row to tune sliding friction might make a resetable(very small number of uses) fall arester. Unscream the screamer. Or trickline backup.
Hi HowNOT2, I’ve recently took a job with Teufelberger Rope in Lifesafety Rope applications. I am new to the Rope industry and your videos have been my sort of educational crash course. I’m a mechanical engineer so I geek out as often as I can. But in terms of this video I can provide some insight on how those numbers are achieve. I can send you my information privately so we can share notes.
Hmu at ryan@slackline.com. Love to hear it
In engineering they have "stress concentration factors" for things like a hole in a bar or a rounded corner. These then come with tables for a reduction in total strength based on the hole size or the corner radius. I think that it would be really valuable to have a similar result for ropes and other climbing gear. For instances a test against carabiner diameter could be done. Or with knots or splices.
Yes!
I suspect there would even be differences in the numbers due to the bend radius, on the items that failed at that point.
That would be really neat. I wonder if that data is already there. If we knew the type of carabineers or shackles used during the test, which you could get from the video, we might have a pretty good data set with the stuff he's already collected
You could also add a few columns to the DB and start collecting those points from this point forward
One system went to the Moon, the other didn't. But just have a converter on your website or something to convert the whole table
@@daveb3910 - ha ha, obvs a metric NASA reference (not sure how it got here) - yes metric went there all the way, so many international objects on the moon. Only Americans sadly died -directly- trying to put some of the artefacts up there (personal delivery adds value no doubt) - you could blame the flavour of numbering systems if you like - the others got to sleep at home another night (mostly)
Science universally uses SI units. (everyone deserves a laugh)
Apologies if you have already covered this in another video, but I'd love to see how wet dyneema impacts these results. I use dyneema a lot in the snow where it often gets wet and am curious if these splices slip more easily. Maybe that's why they recommend longer splices.
ryan, just important, terrific work! Thank you!
I've not had a failure in a single item I have made, primarily for the sailing community but have noticed on several occasions that uneven tapering seems to add roughish points (slight bulges) noticeable after numerous cycles that might...could...possibly lead to a weakness or failure? Hasn't happened...yet...as the generally well oversized and highly inspected nature of synthetic rigging used shows. In practice we find "creep" the far more problematic nature of UHMWPE.
One thought I did have but have not been able to test is temperature buildup during cycling. Would be interesting to see if you could setup a non contact infrared thermometer and see if the friction increase inside a taper is possibly a culprit. Especially in the manufacturers recommended bury and taper lengths.
Once again, thanks.
Long time a subscriber and a designer here. I have actually done some of these tests before, from my limited testing and experience the type of eye splice makes a huge difference. From what I’ve found a locking Brummell is much weaker than a full burry (2.5 fid lengths) straight eye splice with a lock stitch. My understanding is that somehow a locking Brummell doesn’t distribute the force across the 12 stands evenly and often ended up breaking 6 stands at the splice. I believe this straight eye splice with a locking stitch is actually how many of the manufacturers test their 12 braid products… (not totally sure though). If you’re interested I can see if I can dig up the charts from the tests I did and maybe even the videos/ samples from the tests.
Looks like some others have commented similar things but my offer still stands if you’re interested, the tests were with some funky configurations or whoopies and other splices with 1mm and 2mm sk-99
I noticed perfect consistency in where the rope broke, the transition from the splice to a single rope. Tells us clearly where the weak link is, and it's not the length of the bury splice.
I think it's important to remember that when you test to destruction, it has to break somewhere. Having the break in the same place for all of them means the other elements are done right, and that's where the design has an inherent weaker spot. That's not to say the design is flawed though, you just need to account for the known reduction.
Really liked how this video was organized / framed, with the great intro to the units under test, the results on the table and everything! Was very easy to follow along.
I think the standard whoopie sling is very inefficient: 90% of the thing has 2 parallel stands, but you only get 70% of the single stand MBS because of a short piece that is single stand.
I did mine a bit different: i buried the moving tail INSIDE the bury of the fixed eye. Probably the loss of strength is higher because of a wider separation of the fibres, but you get the load split over two strands all the way. Even 50% of 2 stands would be better than 70% of 1 stand.
It would be interesting to pull my version and see the results
I like the idea, but I'm having trouble picturing how it's physically all fitting in the bury.
@@jarodlojeck5150 instead of tapering the bury of the fixed eye, I pull out the end and terminate it, then I feed the moving end trough the buried end, entering just below the termination and exiting just before the crossed splice.
I have only done it in small ropes (3mm and 1,2mm), and they fit with a little bit of milking.
I try to loosen up the fibers around the entry points as much as possible so they can distribute the load as evenly as possible.
If you're interested I can make a video showing it, but it'll be next week
Thank you for these videos! Ryan, you dont realize how many lives your saving with this kind of testing and information. This type of testing platform makes me think of safety issues I had not previously thought possible. It is really great to see you guys taking off! Keep up the great work man!
To be honest, I don't really care about the units, even though I use metric. I can do a rough translation between units on the fly. On the other hand, when both units are shown, I usually automatically jump to the one I am more familiar with without even recognizing that there is another number there. Maybe including both units is more difficult for you and people that are very familiar with both metric and imperial. ... not quite sure, the human mind is strange :P
great video by the way! very informative
Great video! i dont know that ill ever use a whoopie but love seeing the equipment other people are using. Good work!
I'm a hammock dyneema user. I may risk an 18 inch fall. So, I get away with hanging on 1/8" Amsteel and 7/64" Samson loops. I do hang without trees on Tensa Solo poles at times with two whoopy slings running to a couple of home-made boom stakes at each end. I use 14" x 5/16" titanium stakes in 12" long 1" OD 1/8" wall booms with the stakes at 72 degrees. I can use 10" of boom length but stick to 8". Learning the failure points from your channel has been enlightening. Thank you very much! It would be fascinating to watch boom stakes pulled to failure.
So two suggestions. Firstly a handy number guide before the video would help with metric/imperial. Ie stating what 20kn is equivalent to along with whatever numbers we are anticipating to be ideal in the tests. Secondly another option, it might help to write two charts. That way you aren't getting the mess of 30 numbers in one chart yet you're still able to read the data just looking at your side of the screen. Plus it obviously helps people learn both systems, as with both options really. People watching videos don't tend to want to do the work themselves (or they'd likely be reading the information), but as a content creator you can guide them.
Both systems are in our blog. Link above.
@@HowNOT2 That was kind of my point, I don't think most people are going to look. I can do both systems as I'm in a country which uses both but I'd think a few seconds showing some relevant numbers before the test could help a lot of people out.
I didn't know that both numbers would be in the blog. I have no intuition on whether 6000lbs is super good enough. I actually paused the video to look it up at the first mention. Although, now that I think about it, 1lbs ≈ 0.5 kg ≈ 5N. I am not asking you to convert all the numbers, just a text overlay for the first mention ("8600lbs≈38kN"). Another alternative would have been to put the mention of the blog at the start of the video. (This is just a suggestion, I still liked the video)
@@twanvl Pretty much this. Though I also think doing the valuable numbers before any tests would help a fair bit as it gives more suspense and context to the numbers. Its only like 5 seconds to flash it up.
2.2lbs per kilogram is the typically used conversion rate, though I doubt a 10% difference is going to really matter for anything.
As mentioned I think we all liked the video. I don't tend to waste time giving constructive feedback on things I don't like.
Good seeing you yesterday at the rope shop in arlington, learned lots from you.
Love your work Ryan 👍🏻
I do appreciate your work.
First, thanks for explaining why you didn’t include metric in the video. I agree that trying to have both tables would make it harder to make actual comparisons.
As for my thought on breaking better, since the strands aren’t all perfectly parallel I assume this means some strands take the load faster than others and have to give more.
From your other videos, I think I understand that the stretching of the ropes generates heat and that contributes to the failure.
Is the reason pulsing works because it gives those strands a chance to shift?
Or could be those strands heat, then fail and cause the remaining strands to pick up the load and quickly fail. The pulsing would give the strands a chance to dissipate some small amount of heat before being loaded again
The explanation about manufacturers loading the item up to a point, letting it “rest”, then loading it to the breaking point would seem to support that since it would let the built up heat dissipate before loading it fully.
To support why this makes sense, if you look at industrial use like slings for a crane those loads aren’t “jerked” up, they should be getting gently lifted so the load doesn’t shift. Then if it isn’t lifted gently, it’s operator error and not the slings fault.
Please let me know if I’m wrong or completely out to lunch.
(Yes, I mostly watched this because I want whoopie slings for my hammock)
If the bend radius from not having a diverter was a problem the eyes would have failed, as thats where it goes.
2 Woppie with soft shackle.
It looked like friction melt failure even time.
Theas appear to be unset. As the boat man said( video you where testing/making sail rigging) setting was needed to get anything close to full strength .
On the last shot with closeup the failure occurred when there was a surge in the knot setting speed ,
They were set with a series of Jarod to 1 pulls while attached to a set of ceiling hooks, but you're right about the setting. I can't achieve the force needed. The breaks, however, we're in the noose, not the knot. The rotation of the knot as it set didn't help, but the knot held.
@Jarod Lojeck the knot setting not helping is what iwa pointing out.
Hey Ryan, great video. I would have loved to see a test with the whoopie fully extended. In other words, would the stopper be pulled through, create a weak point etc??
Fantastic to see "closer to real world" test setup - the larger radius has its place for absolute measurement, but much more useful to daily use (or failure awareness) is the shackle radius directly on the eye.
Thanks for this information; you are doing fantastic work.
Would the larger radius have mattered when it was breaking at the insertion point of the splice?
@1:27
**buys you a tape that only has metric on it**
It saves lives lol
In the tree industry we use the whoopie as an anchor point by wrapping it around a tree and putting the fixed eye through the adjustable whoopie eye. Kind of like how an ultra sling works.
The needs to be a T-shirt.
"It's not the size of the berry, it's how you tug on it."
A month ago I posted this on your video "These were RECALLED!"👇
~~~
*Howdy gents from Australia! A "thing to break suggestion: **_Whoopie Slings._*
☝️ These aren't climbing gear, but they are VERY unusual, adjustable length, dyneema spliced hitches used for hanging modern camping/hiking hammocks. I made mine from 3mm dyneema, and they are used to hold up my 100kg, when pulled to a force multiplying angle of about 20°.
I've been watching a lot of your content recently - the testing of dyneema was what drew me in, and I noticed that you've done a number of episodes looking as dyneema in sailing applications, which is why I thought it might interest you.
Ryan, another great video. It makes me want to pull my hair out with the scatter in the results.
I started watching your videos about 6 months ago. I am a boater and have been using Dyneema for mooring related attachments. I like the easy of splicing, but at this point I am thinking about going back to three strand.
Is the 3 strand more durable?
I'm in the UK and I love pounds. Pounds are awesome, especially when I have loads of them in the bank......£ Sorry, couldn't resist that one. More seriously, when you've been talking in lbs I do have to check what the conversation is if I want to see the figures I understand better, but for videos like this one where you're comparing a load of slightly different setups to which is the best the actual unit of measurement isn't a problem because you can see the data trend (I think that's the correct wording) anyway. I now know which one of a, b or c is the one I'm going to use so now all I have to do is choose the rope with the correct forces that I might see in this application. Thanks for the video 😊👍👍👍👍
Well done dude, don’t sweat the comments. You’re doing the hard work and we appreciate it.
A significant portion of the study of statistics is understanding different places where variation exists, and then finding the reason that variation exists. The comparison of JUST THE ROPE WITH ITSELF will include some variation due to unobserved factors like batch quality of the fibers between batches, and even along different sections of a 1,000 ft long rope (we call this Population Variance). Now consider making 10 ft hanks to test, and consider Sample Set 1 to have 20 such hanks (randomly selected across the whole 1,000 ft rope) to be tested to destruction. Then take another Sample Set 2 with another 20 hanks to be tested. By accident of the random selection, Sample Set 1 will have a mean break strength (call it Xbar1) and the mean break strength in Sample Set 2 will be different (call that Xbar2). We call this concept "Sampling Variation" in a statistics class, and doing a little studying to understand these two slightly different measures of variation can help reduce the confusion that happens when the two samples give different average break strengths. With those two basic variations measured, we then move to all of the OTHER possible sources of variation (knot type, how well dressed, speed of pull, pulse or notpulse, dirty or clean, etc). If we can isolate these OTHER sources, we can call them 'treatments' and then get on with determining the effects of each treatment. It can be illuminating to then perform a dot plot of each sample (now each sample will have a different treatment), and see how the dot plots show a pattern (show each dot plot separately but with a common scale at the bottom to allow for comparison). A similar graphical technique is to use a 'box plot' for each treatment, and compare the treatments. The boxplots will have visual indications of how spread out the data is, and that visual indication of the variance is often more intuitive. When the box plots of different treatments have NO overlap, we have the clearest picture and confidence that the treatments 'caused' the different performance. However, when there is a bit of overlap in the boxplots, we are not so sure if the treatment was causing the different performance or if we are just looking at sampling variation. And when there is a lot of overlap in the boxplots, we think that the treatments are the having any effect and that the slightly different means are different mainly due to sampling variation. For those who want to get into the weeds of this technique, go search for "Analysis of Variance" techniques, often abbreviated as ANOVA. Don't be intimidated by the terms, and be willing to spend a few hours with a statistics instructor to grasp these basics, and you will be rewarded with much more clarity in understanding all of the testing that you are doing. Perfectly normal humans learn these concepts with a few hours of honest effort and a decent instructor.
I figure we can all convert. Canadians and communists will still complain. I think your reasoning for what units you use and why is super good enough.
Great video 😊
Thanks for including the LBF, I like imperial and if I know its not going to break until the weight of a cadillac escalade then I know I'm good since that force would probably rip me in half anyway if reached :-)
I would have liked to know this video is about whoopie slings from the thumbnail or the title, I almost didn't click which would have been a bummer. I'm here for all the great information you put out, not for some ridiculous rules. Love the channel, just wanted to give some constructive criticism!
I work with overhead lifting of heavy loads daily. I can never imagine using synthetic rope to lift 7000 lbs. I use chain for everything and I'd love to see these dyno tests with some grade 80 chain.
Thanks for the video! I hope the search function in the website works good, because based on the title/thumbnail it's impossible to figure out what the video is about
Graph of the data not found in video is on our blog www.hownot2.com/post/whoopies-tested
Check out our new store! hownot2.store/
I have a question/idea for maybe future video.
I know how ridiculously expensive the medical services and the insurance are in the US.
Ambulance ride in the city - can easily go to $1200 or so.
You are doing relatively traumatic sport that requires specialists and sometimes a helicopter to even reach the patient. How does it work monetarily? Do you pay $5k a week insurance and then $6k to get an ambulance ride? Is everyone in the climbing insured in the US? Do people get bankropted by med bills?
If you are, say, a European climber and came to the US for a climb, what is happening then?
My friends and I are going on our first outdoor climbing trip, and I have been using a knotted dyneema sling as a personal anchor system to clean top rope anchors. I was wondering if the knots are unsafe to have in the sling since dyneema is effected by knots more than other materials.
Thanks!
Very good content! Metric for the win!
From a standards perceptive, I think that if the testing standards for gear is not representative of normal or intended use than it is not useful as a standard. I would be interested in seeing more regarding the testing specifications. Additionally it would be interesting to work with the standards body and manufactures to develop new test standards that include knots, carabineer sized bends, and other common attachment methods. I could see a standard that says a rope must meet 50% MBS with a knot and 90% with a splice or something similar.
The problem is: from an engineers perspective the main point of standards is for quality control, not about real use. For quality control you absolutely need reproducibility and this leads to unrealistic setups. A knot is simply not reproducible within an "engineering point of view". Just an example, remember the sharp edge rope standards: UIAA had to withdraw this standards, as test labs couldn't maintain the sharp edges reproducible.
And in addition we are using stuff way beyond it's intended use. If I look up Amsteel Blue, it's technical a mooring rope:-)
@L W I agree with everything you've said. But this brought up a question. What exactly is 2mm sk95 going to be used to Moore? I'm guessing a small unoccupied air up raft, LOL.
@@daviddroescher :-) Yeah, mooring is the big ones. The homepage states just that the strength is measured as ISO 2307, an allround-standard for ropes.
@@lw671 I understand what you are saying and I agree, however I think reproducibility can be done in the right way. Fundamentally I think you need to test and in the way objects are used. Crash tests are a good example, it could be done in some rig but actually smashing cars is the best way to test.
I think there needs to be a hybrid. There should be QC testing, but there should also be formal independent testing process that mimics real use. I think if you asked most climbers they would expect their rope or carabiner to meet the MBS when used for normal climbing. A good comparison is rigging gear, if it says 1000lb people will use 1000lb. In general the working load on rigging gear is way less then one would expect based on the size of stuff.
@@daviddroescher I use 1.5mm for the ridgeline of tarp of my hammock.
Hey, will there be an upcoming video on the texora slings?? I’m super interested in them
Great video as always, what would happen with a rapid tensioning e.g. a fall when the rope would start slipping before it starts tightening up? The dynema would be hot and slipping before it clamps up?
Usually if it starts slipping, it will heat up, and then catch, but break much lower due to the added heat. Ryan has mentioned in a previous video that he had a quick link on a highline anchor blow, catch on the whoopie backup, and he never knew until he derigged, so it takes a lot to slip.
You should check out the Ropeye Grip Jammer. Incredibly strong, much stronger than a jam cleat or even a jammer. I have them on all my lines. The Ronstan Constrictor is similar.
I wonder if the recommended splice length is for when it's wet or otherwise contaminated.
Interesting, they are tested dry, but Dyneema is also a sailing rope. I've never seen wet tests. That would be informative.
I always pulse the whoopies on my hammock before relying on them to hold my weight, though not really to increase the strength, rather to ensure that they are solidly locked.
Like Shug says, "If you don't milk your bury, you better be wary, or else you'll end up on your derier-y.'
I'd be interested to see if a straight bury with the proper taper would do any better than the brummels.
I really appreciate your videos, and I've been looking forwards to this topic in particular.
As far as the metric police in the end, while I, and most other metric using viewers can do rough on the fly calculations for metric vs imperial am used to alternating both systems for things like (rough) diameters and weights etc, I don't see the argument for not at least putting up a converted chart at the end.
You already have a graph at 9:35 (and already have the converted graph in your blog). I don't see the merit in not just putting them up side by side.
Were the units reversed, I suspect you might go to that extra effort for your (primarily) American viewers.
Anyway, that's my $0.02 (or $0.015 in USD). Appreciate your work dude.
Thanks, it always seemed so extreme to do 2.5 fids. For anything small and short it's just not practical.
That shackle whoopie was super interesting. Thanks for testing.I wonder why it was so much weaker?
The noose angle causes an abrupt bend as the whoopie is under tension. I knew it would break there, just didn't know at what percentage.
@Jarod Lojeck , That makes sense now. Thanks Jarod.
hi, Brummel eye splice in BOTH ends of a 9.5mm polyprop core rope rated at 110kg static load, I'm breaktesting this setup this weekend. How do you guys think it'll go? I'm using it for bag hauling (providing it stands at least the stated load)
So, if the integral soft shackle on the end of the rope failed very low, what happens if you use an eye at the end & then loop a separate soft shackle through it? Does the small bend radius make that as weak? Or is it stronger?
I'm pretty sure the teufelberger splice you mention comes undone as it's meant for class 1 rope not class 2 as you tested it on. The difference is in the slipperiness of the rope. Class 1- polyester is much more grippy than class 2- dynemma. Teufelberger give those instructions to splice their product called Trex, a class 1 12 strand hollowbraid.
It would be good to you retest the teufelberger splice on their own product.
I just thought I'd note that in the arborist world where whooies are common, they're nylon (tenex or tenex tec) so you don't need quite as much of a bury. Also wrapping them around trees is not uncommon to have them 10-20 feet long do you lose length for longer buries doesn't interfere with their use...
Though generally arborists either love whoopie slings, or want to see them burn
I'm fascinated by their use. I learned about them as hammock suspension, but the more I researched, the more I saw how many other areas use them. What's the constrictor length when using Tenex?
Would you still make whoopies as per your old video(two fids for brummel, two fids for whoopie bury)?
Love it!
Do you think if you had a wood or plastic container say like 3 inches wide and deep and almost the full length of rope, and had it filled with water to run the dyneema through with rubber stoppers so it was submerged to cool the rope down as you do the pull, would the break strength be higher?
Going for the purely hypothetical here or are you actually using climbing gear in a waterfall?
More so like lifting an anchor out of the water, or magnet fishing I was thinking
I don't see the diameter of the steel eye directly causing any limiting stress concentration in these breaks, but the friction could be limiting pull-through and generally causing uneven strain between the two sides. Maybe this should be tested with a sheave block to eliminate friction. (I know heavy duty sheaves are not cheap, but it's for science yoh!)
They have for sure built in an extra factor for uncertainties in splicing details, conditions of use, maybe aging, etc.
Maybe the 3 fid thing is based on their large diameter cordage, they make 12-plait amsteel up to huge python sizes for mooring massive cargo ships where the weight of equivalent steel cables is a problem for crews(along with corrosion). I would think that the splice length should be based more on the square of diameter rather than a linear relation.
But then amsteel [UHMWPE] is also subject to creep under fairly low continuous loads, which is why you don't see it used for long-term suspension applications.
While I will totally agree that a sheave block would be better scientifically, it wouldn't represent most practical situations, in which the anchor has friction (or even worse, pinch)
@ Well most practical situations also have side to side oscillation which is even worse than a friction-free anchor. But that is difficult to test with the availible garage-lab. A field study with designated lines and frequent inspection and records keeping would be more appropriate. Practical for a fleet of similar shipswith backup lines, but not practical for climbing with critical [one time use] safety equipement.
Aside from that the primary market for AmSteel is the marine industry and competition sailing, it is unlikely they would develop all new eye splicing standards for just for climbing. A mooring line for example will be under all sorts of up-down and side to side motions with constantly varying tension.
Seems like it would make a great personal anchor on your harness
It's strong enough for that, but taking a fall on something this static would hurt, and might break much easier than a dynamic line.
@@jarodlojeck5150 but normally we use a static sling to make a anchor on climbing.
Seems a good options besides petzl connect adjust for example. It's lighter and easier to carry
@@viniciuscollaco a static anchor with a dynamic rope connecting you to it still has a dynamic component in the system. If you're attached to the anchor by something static, with no slack, and fall, you'll also be ok. If you take a fall with slack in the static system, however, you're likely to break the static line even with a much lighter load than it's rated for. Dyneema is both very strong, and very particular about how it's treated.
@@jarodlojeck5150 But I was not talking about a sling conected with a rope.
Was talking about a anchor to rapeling after. It's just a silng direct to your harness with a carabiner in a anchor point.
In this system there's no dynamic aspect.
My two cents on why the dyneema rope is doing such weird things - context of the material application. If we look at what the primary uses have been for this type of rope, at least initially, it's been mooring and sailboat rigging applications. If you look at the stresses applied in those applications, it's rarely shock loaded or pulled to failure in one "pull", it's almost always an applied load of X and held at that load for some time, or many cycles of X load to less than X for many many cycles.
Now i am absolutely NOT claiming this to be the why of what it's doing, but as you (Ryan) mentioned, we don't know what Samson's testing procedure is, so maybe, again as you mentioned, they are pulsing many more cycles, or holding at X kN for so long to allow the rope time to sort of align its fibers and settle in.
That all being said, maybe it's worth some simple tests, could probably do a basic test to see if there is any validity to the idea. Create some eye to eye slings all identical, do a straight dynamic pull to failure, say 3 to set a baseline, then 3 where they are brought up to something like 25% of the claimed abs for like 10 min. and then pulled to failure. Then do a set held at 50% of abs and pulled to failure, and maybe some bonus of held at X percentage for 10 min. Released and then pulled to failure.
I seem to remember reading somewhere that dyneema actually increases its strength under tension to some extent and then drops again sort of like a bell curve, but for the life of me, i don't remember where i saw that.
Manufacturer's should provide information on how they do their testing to achieve their results, that is the scientific method, others using the same equipment and methods should be able to produce the same result, within a margin of error.
YYYESSS gimmie more dyneema
Could u do a drop falling on a grigri I've recently been setting at a climbing gym and I've been scarred to fall on the grigri or rig we've got static ropes if u wanna make it accurate
I know I am 9 months late on this video, but the "afterthought" test of the Eye to Eye hits an application for holding up my sailboat mast. I have 5 mm dux splice in an eye that I luggage tag (girth hitch) to an 8mm shackle. Or should I just put it on the eye? The answer... It does not matter for strength. It will probably break in the taper. Plus it is so much stronger than the original 1/8" 1x19 wire it replaced so super good enough.
My conclusion luggage tag reduces chafe with the shackle. Keep doing what I have been doing.
I was wondering until you mentioned at 10:30 that the rate of the applied load maybe a factor in the ultimate strength.
With non brittle material, there can be creep with time that may be a factor.
I think you saw that with your pulse technique that it affected the results.
As a researcher, I would see if there is an industry standard, e.g., ASTM, that provides guidance.
Super.
Could you do a test on a Purcell Prussik too please if you already haven’t done so.
The answer your question I don't know who is making these rules but I could suggest a few things as to why they would have a longer splice. One thing might be that you were testing a new one to failure on a single pull. With this splice pull out easier if it was wet? How about dust and dirt ? Does this splice tend to settle overtime? If you had the shortest and the longest and you put them through a thousand cycles and then broke them would there be a difference in the breaking strength and pattern where they broke?
10:25 is explaining "false but technically correct" marketing in a nutshell.
And why independent testing is honestly important. Or public testing standards for that matter.
I think the variation is why there is safe working load application on lifeline products usually being 10% of max
Larger samples are always good!
As for the metric vs US units, I think that you should normalize all data to the rated MBS. This way it is easy to compare different products. I personally find this easier, becasue anything less than 1 shows that the product did not meet MBS in that configuration. I recognize that is might not be the most clear for everyone, I do have an engineering background.
yes! dimensionless units! seems like a good solution to me
That would be pretty sweet to see! I don't think that style completely agrees with the "super good enough" style of thinking though. For a lot of what Ryan puts out (dare I say most?) the point isn't exactly how strong something is, or if his tests match exactly with the MBS, but if it's safe to use. Here's a super hypothetical example: If some crazy hanger was somehow rated for 35 kn but broke consistently at 25, it's still super good enough, but with this analysis the number would be about 0.71. It's definitely very interesting to see that number, but it might overshadow the fact that such a hanger is still safe for general climbing use. Just my two cents :)
But we are not really interested if equipment meets its minimum breaking strength. We are are interested in the absolute value. If a super light carabiner breaks at 20kN even though it’s rated for 23kN I’d probably still buy it.
@@Mike-oz4cv I think it's more like adding it as a column in the table for those who are interested. the unit value (newtons, etc.) woulds still be in the table.
personally I think it would be ideal if he added a "super good enough" minimum unit at the start of the video, then anyone interested in the statistics can look at the chart, and everyone else can just see how it compares to "super good enough" and not worry what the exact unit is. it's best for these sorts of tests to use the manufacturer's unit of choice, unless there's a variety of units being used across the same products.
So it looked like, to my eye, that all (but the knotted system) were breaking around the tapered ends. It didnt really seem like the distance of the constriction sections made any difference. Maybe the proported 8000lb tests somehow negated that issue by internally splicing the tapered ends together? My knowledge of splicing isnt great, is there a way to do that to reinfornce the middle section that doesnt have rope internally?
Your commenters complaining voice cracks me up 😂 good work!
Does anyone know what they are like lubricated (wet).
If you have to pulse a sample/hold it at 8kn for a while then pull it or even change bend radius, then we should just change mbs to stand for maximum breaking strength. Its the same with the start specs given at the start of the video for the whoopie. You're never using it in the setup intended so the numbers given quickly become irrelevent
Just wish makers could be half as open with their testing methods as this Ryan. Not knowing how numbers are produced seriously detracts from their worth (even if its all super good enough anyway)
I use definitely not "as prescribed" whoopies I wonder how much of the "slipping" is due to coating. Bare dyneema definitely slips whole lot more. As for breaking strengts... i'm not really surprised that the end of the burry was the fault point. I guess now it's the time of experimenting with even more gradual bury tapering. Perhaps different progression of it. Not linerar but going faster from large diameter to much slower towards the end of it?
These were a 6 strand taper over a 3.5" to 4" length. The samples in the eye to eye did break at the taper because it has to break somewhere. I think when the eye angle is good, and the taper is good, that spot at the tip of the taper is the weakest point, but not necessarily problematically weak, it just needs to be accounted for.
@@jarodlojeck5150 oh it looked more gradual than what I do, I just wonder given that's the break point could we drop diameter faster in the beginning and make it even more gradual towards the tip.
Awesome stuff!
Regarding the metrics:
i think it is fine to keep it in pounds if you LBF if you bought them within the imperial system.
But I am really greatful you are doing a lot of your stuff with kn, as I am from the EU and can remember the numbers better that way. (Though I have gotten pretty good at quickly calculating LBF from kn....)
If you are going metric, I don't think it makes sense to use KGF, as all slackline gear and ... mhh, as I am writing this I am realizing not the whole audience is made up of slackliners... Forget it! :D KGF should be fine. Its great to have a second chart at the end, even if it is up for only 2 sec so one can pause it there.
I can imagine that the double locked eye splice is not the strongest version. Just one where you don't need to bury so far.
You pulling it quickly without letting it sit might make a huge difference.
Next time maybe try to emulate those wonky testing techniques. Like pulling a little, let it sit, maybe hit it softly with a stick to really get the strands to settle. Pull again (tiny bit), hit softly, repeat. Let it sit at 70% of what you would expect it to break at for a while longer and then break it.
If you really get much higher results (20-30% more) you might have replicated those testing measures.
Also curious about the heat generated, I am sure that can make a difference.
I think that maybe the anomalous result on the whoopie could possibly be down to the smoothing or milking of the buried section prior to testing? Is it possible that the even distribution of force through the strands could be more even if the buried section is thoroughly milked flat before loading?
If a 1 fid length bury is is already "maximum srength ish", it would be interesting to reduce the bury length down, and see at what point the platau begins. Maybe starting at a bury length of 2 diameters?!
👌 Super Good Enough!
Hi, sry for arriving late in the comments section. Grreat videos! The nerd in me likes the content, and the geek in me loves your style ! (or was it the other way around?)
I am interested in increasing breaking strength in double braid dyneema rope, with approach to how you tie the knot. Meaning -> Could you test anything like this in your bench.
Does it make a difference if you lay the rope double before making a 'bowline' or figure 8 knot?
Also, would it help to introduce a passive extra length of rope (say 2-3x diameter) in just the knot, to increase diameter of bends and therefore increase breaking strength? Like, a double rope, but one is thicker and not loaded.
We are rigging a wirecam system with 2x horizontal 10mm lines loaded up to 500kgs force, but could need more safety factor (?)
Interesting. Send us an email thru hownot2.com.
@@HowNOT2 Yeah, thanks - I will. Might take a couple of days, though ...
To get full strength of a rope they use a large Bollard, but what is the correlation of Bollard diameter to rope diameter, For example if you pull a 6mm rope with a 12mm diameter bollard it will break at x kn , if you pull a 6mm rope with a 18mm bollard it will break at y kn, if you pull a 6mm rope with a 24mm bollard it will break at z kn. what is the minimum ratio of rope diameter to bollard diameter to get full strength. How does it change as the rope diameter increases. Would it be fesible to carry along a short section of pipe to act as a portable bollard to get full strength out of your rope.
My guess was that 2 fid lenghts (ie. 42 rope diameters) would be needed because it is the "normal" min bury to be safe.
I'm truly surprised only one fid lenght was enough! I wish I had a scale to test some other manufacturer ropes to see if my normal 2-3 fids is overkill really.
I think one fid is sufficient on a flat test bed, being pulled in a straight line, under dry stable conditions. One fid may not be enough wrapped around a tree, in the rain, covered in sap. The 3 fid length is probably insurance under less-than-ideal situations.
@@jarodlojeck5150 That is a very good point. In nonideal conditions dry flat pull it could need more margin. In real world ropes can get wet, snowy and whatnot.
For anything life support, I always tend to err on the side of better safe than sorry.
Yet I was surprised it did not slip much. I would have assumed it to slip open.
I think you should go back and use an even older obsolete system just to piss off everybody equally. :D
How many stone can it hold?
@@jarodlojeck5150 lol
Something like zentner's per square lessa or something like that that isn't even able to be worked out in modern times. 😁
I’m thinking about it!
@@HowNOT2 or mix and match, do one whole video where the units are lb-meters and watch everyone cry
Great explanation at the end regarding imperial vs metric.
Hey there! Thanks for all your hard work and all the videos!
..but could you pleeeeease use some metric units :D or at least show them both
my brain ist getting scrambled from this inch-banana-footballstadium-unit
Thank you :)
...okay never mind :D I just finished watching your video. Fully understand your point, but my metric brain is still getting confused :D keep doing what you doing :*
Greetings from a german Arborist!
X lbs/2.2.
I think when you're given a measurement, you should use those units.
Someone I know actually brought this up on me because I compared the length of my climbing rope (which is sold in metric units) being 40 meters, to the height of our gym's walls (which they advertise in feet) at 55 feet. They laughed that I was mixing units, but that's just the best way to describe things. When you're given a measurement in one unit, you should continue to use that unit because any conversion is a loss of precision OR requires tracking sig figs.
So if most people who use dyneema cords like this use lbf, and the manufacturers sell in lbf, then you should use lbf, too.
Definitely some wiggle room here, like if your audience was only used to metric or you were comparing against 3 other things and the other things are metric too, then you should convert.
The numbers could be off because of a short tapper inside the braid. I would try a longer tapper on the ends. I am working off of whip making knowledge. This is the same issue as round whips such as bull whips. Round braids have a few traits that could be working against you. 1. Round braids want to stay straight. 2. Bends weaken the braid. 3. round braids don't work well in changes in the core diameter, without strength changes in the strands (larger strands for larger diameters. If you could tie knots in a flat braid the knot may hold better, this isn't talking about webbing. The round braid, as you know, are 2 sets of strings wound in opposite directions around a core. These string clamp on the core, so they need a lube to allow this action without breaking. The engineering for rope changes with each material used for the strands and core.
Many years ago, the sailors would weave a turk's head to strengthen a rope, so you could start adding a more complex knot to your studies. There are books of rawhide braiding and rope braiding that can help in this research. Also try removing some or all of the core in the knots to test the strength of the outer strands. Engineering is about designing a solution with understand of failure. Good luck with your research!
Could the eye-to-eye strength be low because the tapers weren't long enough?
It was a 6 strand taper gradually over 3.5" to 4" of length.
Is there a good reason these are made with such overkill diameter to begin with? Why not use something with around a thousand pound working load?
Best guess for the similarity in break load is the length of single line being pulled on between eyes or the whoopie and that a longer centre section may spread the load more creating the higher results.
You’re so correct about the systems. I grew up with metric and I hand no problem roughly (but super good enough) estimating metric to imperial and vice versa. The people in the „metric police“ are the type to complain about everything and they are just looking for anything. I’m very thankful to you, for giving us backyard data, so we can better understand our systems.
Cheers
I think it’s because you’re not using 3.5x fid bury length, so a lot of the tensions in the eye to eye splice goes to the brumel lock.
Didn't the eye-to-eye splice have LONGER than 3.5x splices?
Dude, I love your schtick & patter.
Your content is cool, too.
I seriously like your attention to detail and open contemplation of the anomalous, where-ever you find it.
My 'Rule Of Thumb' for conversation is; One Thousand Newtons (1kN) is roughly equal to 'One Typical Human Test Mass' of force applied to a pendulous support system with a smidgen of extra because "super-good-enough", right?
-OK ... TLDR follows...
This morning I weigh (mass) a static 182#, that's in lbs. (pounds avoirdupois. [ another Gaulic or Norman idea, I think ] ) -or- 82.5538 kilograms -- of down force, holding still, on the scale.
It seems that the real advantage of the System International (SI) is for folks who don't have calculators, or for whom longer words with more syllables that rhyme well are desirable ( there's a limit on what you can do, poetically, with Ounce, Pound, Inch, Foot & Yard and honestly, the spelling is kinda goofy ).
I tend to use the Metric System for both the cumbersomely large and small of scale -- like thread sizes when I sew-up my strap-loops and rigging.
For life on a human visceral or Newtonian scale, my thumb is an effective 1-inch wide, my boot is an effective 1-foot long. Tip of My Nose to my out-stretched finger is an effective 1-Yard. "A Pint is a Pound the world around". 1-Ounce is a large swallow or gulp. 1-Cup is eight swallows. And I have spoons in my kitchen and no 'deci/centi/milli-liters' anywhere.
100 grams of meat is NOT satisfying!
And how many folks do YOU know who have a two-meter span from left-to-right fingertips? I'm stretching to span 6' & 1/4" and I'm 5' 10" tall.
Yes, threes(3), fours(4), fives(5), sixes(6), dozens(12) and scores(20) are odd multiples if you need your toes to calculate. Human lives are best counted in multiples of seven-years.
Tens are easy to write but Binary is the fastest we have, so far.
I can show 20* on one hand or 31* on one hand, so 5* is for kids just starting to count.
One degree Centigrade is too large without a decimal for temperature as I experience it in the comfort-zone of my house. And I just like the history of Fahrenheit. Maybe Centigrade is an anti-German thing?
The Kelvin scale is useful for discussions of fusion temperatures and the like.
Since all increments are arbitrary -- if I were to be fussy -- the Speed Of Light in 'kilometers per second' should be rounded up to an even 300,000.0 kps!
But hey! I have a Smart-Phone -- so who cares...
Of limited anthropological interest; My interests and areas of service include; Sailing, Wind-Surfing, Sewing, Cooking, Crane-Rigging, Tree-felling and tree climbing and I have always had a thing for knots, braiding, Erector-Sets and Physics.
I guess the really problematic thing is that unless all the manufacturers use the same test in the same way then you can’t trust anyone’s data
Even if they did, those tests wouldn't necessarily give us an idea of how they perform in real situations
@@PaulEdler at the least, though, the same testing conditions would mean if you learn how X with x rating operates in a condition, Y with y rating could be predicted, and the consumer could know which is intended to be stronger rather than testing to appear stronger.
For instance, the ISO ratings on warmth for sleeping bags are difficult for many to grasp because the temperatures don’t really align with the expectations (30deg bags are not for sub freezing) nor conditions in which people use (4.9 r value pads are not common, and many will not switch into a dry pair of baselayers nor tuck and cinch the collar and hood and so on). Plus, some bags have baffle structures which mean fills get easily compressed or shifted and others which have much better structure and will sleep better despite similar ratings
All of this as too long of a tangent to say, at the least you can extrapolate from a similar testing method.
@@zacharylaschober it would. Might reduce Ryan's backlog of stuff to test too.
Did I see right that there was no stitching/whipping whatsoever on the tails? I love when the stitching just explodes as the tails settles in under the high loads. 😅
The whoopie divides the load between the Chinese finger and the central strand. How about a one fid finger trap between two eye splices. To get the finger trap pull started, use a castration band near the cut off end of the finger trap. This should slip an inch or two and then hold. In the drop tower, it would be interesting to see the slip vs. melting point effects. Dyneema is very static stuff and there are times when you want to reduce shock loads, hence the drop tower test. Think of this as simulating a zipper pack. for safety, the rope can loop back on itself, so the loop is in the middle. this would give maximum adjustability and provide a safety stop. When the loop closes, the finger will collapse and expand, creating a failure mode. This could be compared to a stopper knot. Is there a reason this is not in our handbooks? probably not super good enough. I expect highly variable results. One of those do it exactly right or die situations.
Don’t spliced eyes divide the load between the Chinese finger trap and central strand? Why do those require 3.5 fids?
I have been hanging my fat ass from 0.125" amsteel whoopie slings on my hammock for years: tossing, turning, even some light swinging. Some people even use 0.069" (5/64th - 1.75mm) dyneema line. In that application it works very well.
Why is it orange? i thought you couldn't dye dyneema.
As torque test channel often uses beans rather than lbs to compare tools even though the testing and marketing is in lbs the results are comparative. As a viewer that does not intend to climb or use tools beyond my personal car, comparative results are plenty informative
I love the torque test channel.
Problem is it requires a 3rd party to provide such comparative test results.
Without a standard test method that consumers can trust, every company will provide numbers that aim to outsell their competition.
@@Adam1nToronto the need for multiple 3rd party testers as well