Are tapering splices that important in Dyneema / HMPE?
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- Опубликовано: 26 июл 2022
- I was just trying to test tapers and how much of a difference it made and then Teufelberger's splice came undone. BLOG HAS MORE DETAILS & DATA www.hownot2.com/post/are-tape...
Marlow Tapers - • D12 Locking Eye Splice...
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What is Dyneema
01:07 Tapers and Splicing
03:33 D12 Max 99
05:37 NO Taper
09:47 Diagonal Taper
12:46 Marlow Taper
15:10 Samson Brummel + Taper
17:19 Tefuelberger Brummel + Taper
20:31 Amazing conclusion
![[How to] Dyneema Eye Splice | Sailing Wisdom](http://i.ytimg.com/vi/UpkqJ4GRfSg/mqdefault.jpg)
![[How to] Dyneema Eye Splice | Sailing Wisdom](/img/tr.png)
Hi, I'm actually the technical manager at Marlow Ropes, i don't normally comment but I think there are some things to address on this film. BTW it's good to see our ropes performing at, or better than, the figures we quote!
I may be able to answer some of the questions raised in the video and the comments so, in no particular order:
-Big one first: as was pointed out in the film the splice works by friction, if the buried tail isn't long enough then the splice will slip. Putting a lock (brummel) in doesn't alter that. If the tail is too short then all the force is held by the lock stitch which will eventually fail. Exactly as shown. I've seen this many times before so one simple message to all fans of the Brummel lock: A LOCK IS NOT A SUBSITUTE FOR THE CORRECT TAIL LENGTH.
- The lock (done properly) doesn't reduce the strength where the stitches are made because there's double the material content of the rope at ths point (think of the cross section area), i.e. a small loss here does not reduce the strength below 100%. However there is a risk, not observed in this film, if the tail of a locked rope is disturbed then you can get a small loop form below the neck of the splice, this will reduce the strenght of the locked splice. For this reasion I still prefer to whip the entry point and for testing I don't use a lock.
- There's a comment about tail lengths and fids etc. I'm not sure where that all came from however we simply recommend the tail length minimum to be 50x the rope diameter, longer is better.
- There's always a weak point, that's why no matter how good the taper often that's where the rope breaks.
-The ropes that broke in the back of the eye are due to the D:d ratio (ratio of the rope diameter to the pin diameter). When this is large (5:1 or greater) the rope will almost always break in the splice, however when small (less than 2:1) the rope will mostly break in the back of the eye. At the in between D:d ratios the location of the break could be either but it has little effect on the strength. In practice at the very small D:d the rope is often stronger than the shackle as was pointed out early in the video. This assumes the eye size is sufficent, the angle the rope makes at the throat shouldn't be more then 30 deg.
I'm sure there's more comments i've not addressed, sorry guys I need to get back to my day job!
Thanks!
Thank you for your input!
Is a whip the same as a stitch? If not ......data, data,data:) The 50x diameter is more intuitive to me, thanks!
Thank you so much for contributing. I will buy your products because of this.
@@kraftzion Measuring in fids is the same thing, it's just a more round about way of getting there,
This could be crucial information for people who have nothing but their riggings to keep them safe. Sailboats come to mind, and the people who live on them full time.
It is! I both live on a sailboat and am a professional rigger 😂. I didn't know any of this for sure but for lazy jacks, pennants for the tops of sails or other length limited or non critical load bearing pennants we do the Brummel/short tuck, something like a backstay gets a 3.5 fid bury with a Brummel. And I'm glad we have done it like that!!
I learned the Brummell so that I can better secure my camera kit
in the back of my car… Then I showed my buddy this channel, and now he wants to make some new Bow Lines for his sailboat!
I came here for the same reason. My biggest take away is the use of a thimble to maximize the radius of the terminus is at least as imprtant as tappering the tail.
I am a hydrofoil kitefoil Formula Kiter and that’s the exactly information I was lost about. I did the Brunel Lock Splice but was having trouble to dig the rope inside it. And I was asking myself, “is that relevant?”. According to the videos, yes that diging matters!
This info needs to be shared with the 4x4 community most of us have dyneema winch ropes, and I've seen so many people tie knots in it, esp for the loop or use metal cables locking hardware to make loops.
As a wrecker driver who uses rope, I will say if you brake it on scene and absolutely need to use that winch still, I tie a quick figure 8 and adjust the rigging to account for the loss of strength if need be, It takes 5 seconds to tie the knot and gets the job done until I can get back to fix it properly. So in my opinion when time matters tie a knot and rig accordingly and splice it properly later... Just keep in mind you will not easily be getting that knot back out so you'll fuck with it for 30 minutes to keep your length or you will be cutting a few feet off to get it out of the way.
@towtruckaj that is 100% fine with rope. Should have made that clearer sorry.
Dyneema sadly will melt in the knots and has a high chance of breaking well below its rated safety limits.
The most plastic the "rope" the more likely that high loads, static or shock, will cause the rope to start melting from friction and snap.
It's why I said the 4x4 community needs to know this as the use of dyneema (its a brand name that has been used to cover all brands of that type of "rope") is very wide spread, cable has become very rare due to weight and size.
For tie downs and the likes I have very little issues with putting a knot in it to get you out of trouble.
Also got to remember that a large part of the 4x4/offroading community buys gear they don't know how to use. Then when it's needed they don't ask for help, just use it, rarely maintain it etc. Then when they use it, well they go to 100% right away, so many times I've seen someone snatch strap (kinetic strap) someone, going as far back as possible for the run up and flooring it, as a first attempt instead of starting with a gentle tug then working up. So you have an unmaintained, likely filthy from being on the bottom of their kit, out of date, cheapest and even likely well underrated for the vehicles being used. It inevitably snaps, so they tie knots in it then get shocked when it snaps again. Or when putting it back in they just gather it up in a big bundle, throw it away wet and dirty, next time they can't be bothered fully untangling it, has a few knots in it, then it snaps at the knots.
I noticed when seeing snapped "ropes" in the 4x4 community its at a knot, and usually on snatch straps or winch ropes....or at sharp parts of the vehicle because no recovery points best case...or at the bloody tow ball at worst.
@@azazeldeath That's just the reality of the 4x4 community with anything, Some guys are well educated in recovery techniques, Technical info on their equipment, etc. Others are just some fool who bought a bunch of cheap garbage that imitates what they see in videos and they get themselves in troubles, Not to say it's just the 4x4 community I see the same dumb shit happening from so called "professional" wrecker "operators" In my industry. It seems very few of us in many industries and communities alike actually put the time and effort into learning and mastering our craft.
@towtruckaj so true, used to be a mechanic, found similar in that industry. It only really concerns me when their lack of ability to do any basic learning can endanger others, like me, my loved ones, or friends. Or even really anyone. Hurting or killing yourself because you didn't want to learn or study something sucks, but that's all on you, when it hurts or kills others then it stops being acceptable in any way in my opinion.
As with 4x4 ,yachting people work on MBS.Ive been involved with yachting and lifting industries for most of my life.Working with MBS,is an accident waiting to happen.There is NO safety margin built in.ALL the bush boys will want to jump on me.I have run NATA certified testing facilities.I would say that if there was enough SAFETY FACTOR built into the system,no matter the splice or knot,you would be OK(disregarding slippage) In yachting on many occasions,I’ve been on people’s yachts thinking,shit,I hope this doesn’t shit itself 🤓🤓🤓🤓Pile on BOYS .
This is why I'm a Patron; straight to the point, testing, results. Keep it up!
yall are so wonderful for what you do, thanks for keeping folks safer.
2 years ago I started a business that makes soft shackles (using the diamond knot: for sailing purposes that is secure enough) & other Dyneema products for sailboats. I always carefully taper the ends, as it is 'known' among riggers that if you don't, it will greatly reduce the strength. Interesting to see in this video that even if you don't taper and use an appropriate turn radius for the eye, it could still break at the eye before the non-tapered tail.
Lancelin (a high-end French rope manufacturer who's ropes I use) instructs to use 80-100x diameter for the bury, of which 20-25% is meant for the taper. So around 60-75x for the bury, and the remaining 20-25x for the taper (meaning a LOT of bury and a LOT of taper for max strength).
I also import HMPE (non-branded unlike Dyneema), and use it to create winchlines and large soft shackles for 4x4 recovery purposes. Therefore I'm very curious for your next video that compares different types of HMPE!
@HowNOT2 if you ever need to get in touch about anything Dyneema/HMPE related, please do! My business is called SoftShackleShop and I'm based in the Netherlands. You'll find my email adress on the website.
I'll email you. I think you'll be shocked how much more strong the chineema was than the other 5mm dyneemas.
If I made dyneema products to sell, I'd probably taper and bury according to "manufactuers specs" and common belief. I only break the rules if I make stuff for myself.
HOWEVER, I've broken a LOT of soft shackles and not soft shackle broke where I didnt' taper it. It's always the noose or one strand coming out of the knot.
@@HowNOT2 "Chineema" made me laugh way more than it should have..
YES! I have been wondering about Brummel splices forever. Awesome video, thank you!
Glad I'm not the only nerd :)
the Brummel splice is used in all sailboat rigging.
Hi Guys, what a fantastic channel you have, it will be great to see some dynamic tests using the gri gri and other different devices as a leading rope solo belay. Thanks again for the time and great effort you make to create such a great channel and all the super useful information you guys share here.
I loved this video, something what also could be very interesting could be comparing slow pulling dyneema vs throwing it from the drop tower to see if the dynamic forces make them breake way lower as everyone says. thanks a lot for all this videos
You are a saint for obtaining and sharing this data. Thank you.
Good stuff! I’m a sailboat guy and a climber. I’ve been seeing dyneema in the boat world for quite awhile. I was wondering when it would really start to appear in the climberverse. I’m glad it’s starting to see more use from climbers, cavers, etc. My experience, anecdotal only, is that the length of bury is the critical component in eye splice strength. Some of the really fast and really highly loaded catamarans and trimarans use nothing but synthetic rigging. It’s hard to find much metal anywhere on those boats. The masts are held up with synthetic fibers, though not exclusively dyneema, and the buried tails are REALLY LONG!!! Glad to see your tests come to the same conclusion. Thanks for doing it!
I've always doubled the amount to bury as suggested, just from my own fears.
Thanks for verifying my paranoia. Your works does a LOT of good.
Thank you for that.
Keep these videos coming !! Love it
I guess it depends on what you are using it for as to whether you do a full bury, brumel etc. I use 6mm dynema on my sailboat, and 20KN would pull the boat apart before the line broke ha ha.
The Brummel reminded me a lot of how water ski ropes are eye spliced. I don't think forces tend to be high enough to be an issue even with the most aggressive knots, so the issues is more of the knot slipping. Regardless, I have seen lines break. It might be a fun diversion to spend some time on the water, get some line scale readings of skiers doing various styles and tricks, and go home with some rope samples for the slack snap.
The
Thanks for the video, it may be that the eye failures were more to do with lack of smoothness of the pin than the length of the eye, Dyneema is very sensitive to rough surfaces and highly polished thimbles and fittings are generally used.
As always, excellent content. I am a sailor, and use dynema in various locations, although never in life critical situations. When I am doing my splices, (usually without the Brummell) once the tail is buried, firstly I feed some heat shrink tubing over, beyond the bury, then feed in a sliver of hot glue around halfway down the bury, between the tail and the outer. Depending on the location of use, sometimes I will roughly hand stitch a lock, but always whip about 1 inch from the loop. Then pull the heat shrink tube up to cover the whip including the buried hot glue sliver before using my ex's hairdryer to shrink the tube at the same time as melting the hot glue internally. This seems to stop any creep when attaching/detaching the loop from use, particularly in situations where the splice is slow loaded, as in tightening bottle screws for the wind generator guy lines. I don't know if this would introduce issues, but hasn't let me down so far (famous last words).
Per the hammocking community (we love our whoopies) the recommended locked brummel splice has a bury of 8inchs for 7/64 amsteel (1600lb) which is 8-strand sk78 with no pre-treatment. I use a bury of 2.5" on a locked brummel spliced 200lb 6-strand Technora guyline. So yea that 8inch splice seems tiny for your thick rope.
Really good video. Thank you for doing this one!
Maybe the tapers allows it to "load balance" without having to stretch at all? So you really are getting full strength if you taper it!
The numbers are on blog www.hownot2.com/post/taper-tests and the soft shackle shirt is at www.hownot2swag.com
Check out our new store! hownot2.store/
Your insertion tool is too sharp and is making micro cuts where the needle exits the dyneema.
:P
FYI - broken link
Link doesn't work...
I finally decided to become a Patron. You've done so much for so many communities and have created so much valuable information. I want to make sure you're able to keep up the work and be able to focus on testing/projects rather than funds!
Thank you!
Awesome video! As always ))
Thank you, keep going
The reverse video at 19:46 makes it look like the rope is some sort of organism.
I agree those graphs looked great. Thanks for the fun and interesting video.
I'd be interested to see how the performance would be changed by dipping the splice in liquid whipping before/after "setting" the splice under load. I've considered using the stuff as a chafe preventative that might also prevent slipping while unloaded. The question then is whether the liquid whipping acts more like a bonding agent or a lubricant when pulled...
It’s been my experience working extensively with 1inch and larger dyneema, nylon, poly, and other synthetic fiber rope/line that the point of failure will almost always be at the very beginning of where the splice starts. This is the point of where the natural lay of the fibers are altered.
Wow! This taught me so much
I'm a "tree guy" and make/build/splice a lot of my own safety lanyards, slings and ropes.
I am very curious how a triple locking brummel splice would perform. I use a 50x diameter
bury with a very gradual taper on the cordage for my personal safety lanyards which have
a 12 strand dyneema core. I also lock stitch/whip the eye due to the constant loading and
unloading the happens while work positioning and working up in the tree.
Thanks for the great video and keep yourself safe! 😃👍❤🌲
Randy
Glad to see another tree guy here
@@fullthrottletreeservice4101 I'm hanging on my own splices and knots. Whenever I see videos like this pop up I try to at least take a quick look to see if there might be some new information I should be aware of. It's really good stuff to know when "your life is on the line"..... literally. 😁👍
Keep yourself safe! 😃👍❤🌲
I can speak from experience, some of your videos are actually saving lives. This is invaluable information. I'm surprised this channel isn't bigger than it is. I always recommend your channel to the climbers I meet.
We have been told you can do the Brummell splice either with an eye or joining 2 ropes, but you have to go through 3 times as close together as possible without the tail inside the main rope. We have used this in the line trade.
Really nice explanation of a tapered splice...
Great video. I use a lot of Samson Amsteel in my hunting endeavors hanging from trees. Just like climbing or rigging my life is literally on the line.
This video helps put into perspective the likelihood of a failure due to an improper splice or short bury. For instance, my static line is rated around 6500 lbs MBS and miscellaneous carabiners between 11-17 kN rating. If an unburied brummel lock hits 20kN its hard to imagine that with a decent bury and taper that the dyneema would be a fail point for me.
What's more interesting is the eye size and how that affects breaking strength. However, again, nowhere near a force that be concerned with such as my 180lb. body hanging from a tree.
Awesome experiment...I use the Mobius brummel splice with a long tapered bury for sailing rigging. I feel a lot safer after watching these videos.
I've had my whoopie sling pull out while hanging in my hammock. Luckily I was hanging low on my porch. I was using some 1/8 8 strand which is probably too small. Careful tapering was the difference between success and failure.
Oh my... glad to hear it was on the porch. I use my hammocks in my bedroom and have had a few crashes trying out different things. (Rappel rings, carabiners, buckles, lashing) No injuries except pride, but a couple of close calls with stuff underneath).
I just ordered some whoopee slings. Eeks!
The eye or the whoopie part? I haven't usually tapered my whoopie because the adjustable part slids out of the center immediately instead of gradually and I figure it will break there. Ironically I haven't tested them even though I used them a lot back in 2016 for my anchors. It's on the list
This is the most useful channel on youtube.
Great video! So I am probably going to use Dyneema 12 strand to rig up some airplane skis instead of the standard steel cable. Having no experience with this - your video is very insightful! We will be using thimbles for our eyes (which you might like to try for your tests) and will be using adhesive lined shrink wrap over at least part of the “buried” bit. The stuff we are using has a 5000 lb rating which is more than the cable I would otherwise use. But I wonder if the cable is as “fiddly” to get rated strength from… if you want to do some tests for this application I’d love to see it! I’ll make up and send you the test pieces if you like. It would be worth it to me for your results! Cheers,
Ken
This is really useful for the sailing community. Thanks for making this! I learned a ton
Might be different in the climbing world, but as far as I understand in the boating world the taper in the Dyneema was to allow for the spliced rope to flow smoothly through a pully. i.e. you don't want a big lumpy change in the thickness of a rope when you pull it through a pully as it has a tendency to get stuck. Never heard of anyone saying that it made it stronger. But great test! I've only heard of anecdotes and stories around it so it's great to see someone putting this to the test.
@Nathaniel Brough: Tapering follows engineering practice (not sure about traditional lore in various sporting cultures) that sharp transitions induces stress risers which induce fatigue points and increase the likelihood of rapid failure under load... Not really "making it stringer" but not making it weaker is key. cheers.
@@kadmow Yeah I'm aware of the engineering behind stress concentrators.
Thank you for challenging my comment, it appears that I've got to examine my opinions on this a bit further.
In general when it comes to boating most of the breakages in dyneema occur either where the rope first threads back through itself in the brummel. The other common failure is when you terminate your rope in a brummel similar to a soft shackle, then you soft shackle the top of a sail to that rope. The rope is only as strong as its weakest point. So I guess in typical sailing use the weakest point isn’t usually a poorly tapered splice. But I still think that you are right that a poorly tapered rope would be a stress concentrator.
The only time I've seen failures occur at the taper, is when someone has done a diagonal cut taper with a hot knife. People seem to be worried about it fraying? But the end result is a hard lump where the rope has melted together. It's not really any weaker than a regular diagonal cut, but it results in an abrasive point inside your splice that over time can significantly reduce the strength of the rope.
I'd be really curious as to how much of a difference a thimble makes with dyneema though. Seems like it would make the taper more important.
I've been waiting for this video for a while, this is real science that's super awesome to have accessible to anyone now. (blah blah statistical significance blah blah, there are limitations to it for sure, but your methods are out in the open which makes it 100x more valuable)
I find all science has some flaws to it and I think showing ours helps people know how to compare it to other studies. Glad you like it.
Super informative!
for your last splice looks like the outer strands can close in on the taper. I wonder if the location you first pass it through adds too sharp a bend to the fiber and doesn't transmit forces. You should pull to 14kn and then pick at the area around the taper to see if its actually tight....Or better yet use a thermal camera and watch where the heat builds up.
Would be super interesting to see you strength test a "nicely" vs a "sloppily" tied Figure 8 Follow Through knot
Would love to know what's going on when you use a locking brummel on a continuous loop. It reverses the direction of the splice, which I assume can't be a good thing.
My biggest takeaway is use a thimble to maximize eye diameter. Without a thimble, there doesn't seem to be a point to worrying about the bury taper.
And along with the use of a thimble, thimble shape. Using a low friction ring seems like it would induce a smaller radius and therefore a stress riser at the bury than a tear dropped thimble like a Ronstan sailmaker's thimble.
Still remember the day my grandfather rolled up to the boat with a roll of amsteel grey to replace the wire rope on the boat. In the 25 years since I've used 2mm twine up to 1 3/4, from a half dozen domestic companies. Sitting in the truck typing this, have a custom ordered 22mm 1500' roll from Japan that has a new uv coating.
We loop through brummel splice with a long tail in settings that have lots if load variation. We assume 75% loading and upsize accordingly. More gradually loaded lines are straight brummel with a deep bury and lashing.
Uv kills most, internal fiber abrasion from sand and dirt kills the rest. I'd rank 95% of my real world breaks at the eye. The rest usually appear to be from a sharp corner. I've blamed the ones that break at the base of the taper to sharp edge contact but after this video maybe that's a taper break.
You should do a video testing different types of repelling and pit ropes at their full length
Usually a short taper like the one that slipped out with the teufelberger instructions you mentioned is meant to be executed with a class I rope (made out of fibers like polyester or Nylon) vs a class II rope (made out of high modulus fibres like dyneema or LCP like vectran for example). I didn’t personally research the teufelberger instructions but I suspect this is where there might have been confusion
That is what people are hinting at. Their pdf didn't specify and is pretty important to clarify I think
As a no climber I was think from outside the box that if the brummel spice was continue weaving it in and out multiple times from both end to but up inside would not have a weak taper and produce a higher Kln. Also it would be interesting to compare out a traditional brummel splice with a standard spice on the same dynema and them compete graduated multiple weaving brummels to the winner to find the champion. Jim Rodgers
Great video. Thank indeed.
I regularly use HMPE for rigging and have 2 reasons for tapering that you didn't cover. One is that it runs more smoothly through rigging blocks and the other is that when repeatedly running through blocks the shoulder it makes can be pushed up the inside reducing the length of the bury over time.
those different splices sounds a lot like two of the major offroad recovery suppliers use. Factor 55 and Yankum Ropes both agree on tapering the ends but have different opinions on depth of splice and how the tail of splice enters after the loop is made.
Having been in the game of rigging manufacturing and working around test beds for many years 👏👏👏👏 very thorough.As a side note,did some testing on Australian made shackles compared to (imported) these were used for general lifting purposes, the imported would yield at proof load,fail,twice the SWL .but would break higher than the Australian made shackles 🤓🤓🤓🤓 Asians,can make anything LOOK like the real deal .
Very interesting. Thanks!
The last step of the Teufelberger instructions says to "Cross stitch with whipping twine." I missed whether or not this was done for the video. I would love to see a comparison between the two.
I don't think the stiching was done. I wonder if Ryan would be interested enough to test with the stitching, but my guess would be that the while the buried tail slips out, it will probably rip the stitching too (?)
Whipping the rope is to keep the eye formed from changing shape and size when the rope is not under load. Or to keep the splice from unwinding on a woven splice. I don't think it would add strength, but maybe even reduce it because the extra stress on the dynema where it's wrapped when loaded.
I want to test stitching, but that is generally only to keep it from coming apart when it isn't under load. 1 fid length slips generally so I could test that length with and without and actually get a difference. Once I'm 1.5 fids it typically holds so I wouldn't know if the thread is doing anything. I put it on the list
@@HowNOT2 when talking max numbers it probably doesn't matter but in real life it makes the difference in lower load sailboat applications I bet.
I have had customers come in with a "broken splice" on like a 10year old line. It was really just a soft eye (only cover, maybe 3-4" bury if lucky with nothing but a whip holding it and they used it to haul up and hold their sails with it for all those years with no idea haha. I always take great care in my whips/ lockstiches for hopefully some dumbass insurance against stories like this 😂
Teufelberger does have a document for splicing the high modulus lines withe a longer bury than the one shown in the Brumel-locked splice. I would use the same (longer) length specified for the high modulus lines even after adding the Brummel lock, as the Brummel is not for strength, but to help keep the splice/taper where intended. the cross-stitching has the same purpose, to fix the location when unloaded, not a as a strength member, though I suspect it may have some effect to prevent initial creep when loading and make a slightly more secure grip on the buried part of the line. the same way that a few pounds of tension on a jib sheet with 5 wraps around the winch can hold a thousand pounds of force from the sail. MOre wind in the sail, more wraps on the winch.
Thanks!
Excellent piece and as a Corinthian yacht racer who does his own rigging I was interested in your eyes breaking and your advice on eye size. I by habit tend to use longer eyes to allow snap shackles to be attached and detached easily using a larkshead hitch. Did you consider trying the difference using a larkshead which consensus says spreads the load on the shackle and eye ?
With the blunt and diagonal tapers, the taper is probably putting stress on odd strands all the way in the eye. My guess is the eye diameter does matter, but is more affected by the type of taper. Hence, a proper taper puts even stress on all strands and your eye is therefore stronger, and the taper is the weak point again.
That is something I had not thought of, I would love to see some data on this.
It’s a good thought. Hard to test specifically
@@HowNOT2 If you had access to proper slow motion equipment aimed at the back of the eye(s), you may be able to see which strands are breaking first. Possibly color code each strand to compare where it is against the buried end.
I do not know anything about climping but have been sailing 40+ years. The sailing comunity have used dyneema for a few decades, i guess. a long taper is an absolute must for a strong eye/splice. if you want it even stronger you skip the brummelsplice and just burry it and secure it with some stitches, thats the strongest way to do it.
Great video 😊
谢谢你的测试，我一直在看，支持你
Thank you for your support!
I’m about to make safety guard wires for our yacht using 6mm Southern Rope Super-12. To get over the tight radius issue I’m going to add stainless steel 316 tube thimbles. The Super-12 will be support through the turn. I know you can’t use these in climbing but would be interesting to know if these solve the break at loop issue.
I would of thought the forces you are loading are creating friction between the two layers which is also creating heat to a low melting point rope. That would explain the breaks at the taper and the eye breaks are rubbing on the shackle. Have you tried a dry vs wet test? The wet sample should help (in theory) with the dyneema not heating up whereas in normal rope it will reduce the SWL by 20%.
(disclaimer : I'm no molecular scientist but I do have 20+ years experience working as a Rigger and make my own Soft Shackles) thanks for sharing
VERY interested to see what difference lock stitching would make in the pull tests
Great video
Watching this video made me decide to replace my steel wire rope slings with Dyneema. To protect them, I plan to wrap them like you did in the sailing videos. Melting the Dyneema isn't a concern for us, and we pad everything regardless of the situation. I want to save the weight and still have the benefit of the different configurations that a rope sling offers. If I send you some samples, do you want to break them in various configurations? As always, good work! You earned yourself another patron today.
Email me if you want to make a batch of samples for another niche part of the process. Ryan@slackline.com thanks
From 12:04 on, the way that the ropes twist tightly, after failure, looks so cool that I was thinking you might repurpose them as lanyards and handles, (either for offered for sale, or given out as gifts for subscribing). In fact, there might be a market for simply any ropes that you have broken in a video. Selling one rope buys the next. Just a thought.... 🙂
be careful with shortening the samples. this material is rate dependent. shorter sample with same pull velocity means higher strain rate and therefore different behaviour. BUT its much more complicated because you have non homogenous samples (tapered parts spliced parts plus the middle part etc.) so comparison is complicated.
Be interesting to get that on the tower. Big high load shock fall on a splice, then a bouncy long abseil to see how the splice holds.
Yup. I'm wondering if I just shock load the stuff if it breaks a lot lower. That's literally what I'm doing on the tower next when this weather cools down.
@@HowNOT2 And if once it has held the shock and been deformed, the subsequent release and load cycle of abbing off or even more so jugging back up would work the now looser splice free?
As someone who splices my own ropes this was very interesting
Thanks
They want us to use this for sailboat rigging instead of Stainless cables.
Generally costs a bit more than half the cost of Stainless, generally less than half the longevity of Stainless. If you're willing to look the other way stainless might last 20-30 years before any (visible) damage occurs. As in there's probably some hidden corrosion, but no strands yet compromised.
Your reasoning is sound but twenty years would be max.with proper inspection.Big problem is and I’ve lived on yachts most of my life.The insurance company’s want you to change the standing rigging replaced every TEN years.DONT even talk about CARBON MASTS ,they don’t want to know because they don’t understand,so with synthetic rigging,I wouldn’t even entertain the idea.There are so many idiots in the insurance game(they have no idea) I had a claim a few years back for my yacht.They denied the claim BECAUSE WIND WAS INVOLVED,it was resolved but I was dicked around till I was pushed higher up the chain till I got someone that understood 🤓🤓🤓🤓
VERY interesting! have you ever tested Grog splices? it's an interesting concept to connect semi-permanent rigs but the weird thing is that I read that they recommend to bury just 4'' to 6'' and that seems too low compared to this tests, why such a big differience?
THANKS for all your hard work!
Yes, it's one of the videos I have coming out soon! I dont' recall grog loops slipping probably because both tails are buried that length.
Thought it may be worth pointing out my assumption as to why teufelberger gives the Taper instructions that it does...
Teufelberger makes a hollow braid called Trex it is made of polyester. It is not made from dyneema type fabric so does not have the same slippery characteristics.
It is more similar to samson tennex which you have tested in the arborist video, which gave 100% strength with a single fid bury.
In the testing that I've done the distance between the brummel and the taper start is important.
Be very interested to see a double ended v's single ended Brummel splice.... double ended I'm OK with but the inversion on the single end style always makes me flinch.
First I would like to say I love your channel and I am a big fan of your testing. But second, a criticism: At 5:21 of the video you casually "explain" that stitching is not needed for strength, that it is just there to keep the splice together when it is not under load. Obviously stitching at the throat of the splice will keep it from pulling apart--no argument there. But stitching, even of weak thread, can add tremendously to the splice strength, or more precisely, make possible a shorter bury that still delivers full breaking strength of the rope. The famous capstan formula shows how wrapping a rope around a bollard allows the transfer of force via friction from a loaded rope to the bollard in an exponential fashion when the rope is wrapped around the bollard. One use of this phenomenon is the tensionless hitch; another is the buried splice.
Consider that the core of the splice supports half the load at the eye, but that that tension is completely transferred (gradually and exponentially) to the cover over the length of the splice from eye to end of taper. The stitching at the throat means that there is already significant friction between core and cover in the stitched region, a sort of head start for the splice, meaning less bury length is needed to develop full splice strength, or, conversely, that the manufacturer-specified bury length when combined with adequate stitching is Plenty Good Enough.
@nolotengomiedo: Whipping the eye - will most likely provide significant increase in "pull out" strength in the instances of a short bury - more so than a simple non compression stitch, but full stitching (as per some Samson Rope demos) probably goes some way to "simulating a short whipping.
NB, for climbing and short slacklines - probably all of what was demonstrated is super good enough,, lol..
@@kadmow Yes, good point about the whipping. To get really technical, I should point out that stitching gets tighter as the load increases but whipping gets looser because the rope everywhere and the splice in particular shrinks in diameter as the load increases.
I did a lot of splice testing years ago, and even though the splicing instructions of the manufacturers (Samson, etc.) are very conservative (as they should be!), I personally use a short bury only with a locked Brummel, and only when the bulk of a long bury is a serious issue. When pulled to failure, the combination of a locked Brummel and a very short bury does pull apart, but the lock turns into an incredibly tight little knot that still delivers a significant percentage of rated rope strength.
It probably adds something but for the amount of stitching/sewing added, it's no where near the amount of a sewn sling. Since I can consistently get 1 fid lengths to slip and anything above 1.5 fids typically hold, I can do 1 fid and add 1 stitch, then 2, then 3 and see if it gives me more strength.
@@HowNOT2 It's interesting that you mention sewn slings. I never tried to break one, but I always wondered about sewing patterns, number of stitches, spacing between rows, etc. I think the engineering and physics of sewn slings is substantially different from bury splices, mainly because there is no Chinese finger trap effect with the slings. Also, a small amount of weak stitching can be the difference between a splice that fails under a small load and one that supplies the full strength of the rope.
Save yourself 2 of your proposed 3 experiments and do this: make a short splice in Dyneema, maybe a fid-length or so, one that is not too hard to pull apart. Now make the exact same splice a second time. This time put in 3 or 4 stitches of ordinary sewing thread at the throat of the splice and tie the thread ends together. Once again try to pull the splice apart.
Some great testing thanks but you pins for the eye splices should not be rough old galvanized shackles , they should be super smooth and polished SS or similar . If the dyneema is moving on the pin that completely different situations as you have abrasion happening .
Get shackles that are smooth and reverse the shackles so the dyneema does not jamb in the corner of the pin to shackles.
I come from the sailboat world and dyneema is often under continuous load for many months at a time , creep is a problem !
I like to loop inside the eye so it gets double, and then bury and taper as per specification... maybe you can try that way?
Good video.
Sampson ropes has a certification program for splicing various types of rope. I have certification in dynema. None of the methods shown appear to be done according to the manufacturers recommendation. (Hard to tell exactly without seeing it made.
Main point - if lives depend on it always follows the manufacturers instructions.
And check for updates before every splice. Because I have seen them change slightly in the last few years
Final comment. That scrunching could be by design. Some dynema has a slightly longer strand to reduce the snap back of a line breaks.
We followed the manufacturers recommendations and it slipped. So I'm not in agreement of "just follow manufacturer instructions".
That’s extremely good to know. I have sent sample splices to Sampson where they will inspect one for splice execution (to see if they were done correctly-almost impossible to mess up a dynema splice but they check anyway) and then preform a destructive test. One person I spoke too at their technical department (who was analyzing one of my splices) said that’s one of the methods they use to modify splice instructions.
You may be on to something and I’d bet they would be very interested in testing some of your samples. My experience has always been positive. They take this stuff seriously and want to know about potential problems.
Rule of thumb, eyes usually need to be 12X the diameter of the line. On some lines, the length of eye needs to be 36X the diameter of the line.
thanks for those tests! will you also test the minimum bury length required for 90-100% strength?
i am using whoppie slings from 8mm teufelberger dyneema with 30cm buries (inner length), thats about 2 fids. so far without issues but i have never taken them close to their limits...
I’ve done a quick test before and found 1.5 fids was absolute minimum where it is 50/50 slips or breaks. I’ve done two fids for all my whoopies. I’ll test it as an official video though. I do wonder if cyclic loading would be a problem but stitching should mitigate that
@@HowNOT2 ok, thanks! looking forward to the vid.
maybe you can have different manufacturers/SK qualities in there too, in case it varies...
do you include the taper within the 2 fid lengths or is that in addition?
@@sciencebug314 the different sk qualities we tested are all very properly buried, tapered and lock stitched.
Interestingly enough Teufelberger doesn't state the rope material for which their splicing instruction is supposed to be. Atlantic Braids explicitly has a seperate splicing instruction for dyneema rope. As does Samson Rope.
Interesting. It looks 12 braid. I wonder if another material wouldn’t slip as bad
@@HowNOT2 The stuff in the picture looks a whole lot like dyneema. But e.g. Samson Rope has a rope named Tenex which is a 12-strand single braid but is made out of polyester. And polyester shouldn't slip as much.
@@bjornlange7483 So the polyester theory has been now told to me twice now. I bet that is what it is but ideally that should be made more clear on the PDF but it does make a lot more sense.
@@HowNOT2 They definitely should clarify that.
I was thinking this so I specifically looked up Endura 12 instruction videos from Teufelberger. It'd past my bed time but doesn't this taper still look too short? ruclips.net/video/Yox_UA2FXkE/видео.html
Hello,
Thanks for all good tests you're doing. It's very helpful and confirms the security factor.
Can you try, test, maybe develop a new kind of loop that could be more resistant?
Like tested in your video, certain loops failed, and we never know in advance if it's going to fail.
I had an idea, but I don't know if it's possible.
Can we make double loops to divide by two the pressure into loops? Or put a kind of cushion in between the UHMWPE and the metal part of the fixed part?
Maybe when a pressure is applied in between UHMWPE and steel there is a reaction.
I'm trying to understand these failures because I will not install on my sailboat UHMWPE that I don't know if it's going to fail or not...
Thank you very much,
Cheers
There is a single-hole loop splice technique for locking a slick bury that is formed by (1) piercing the rope with the working end to make a loop and then (2) to take the working end around the standing end to overhand the exiting working end and then (3) to enter the same exit hole to begin the long bury. I found this splice on both ends of what seems to be a 16 strand braided polypropyline dock line. Your thoughts about the speed, strength and appearance of this simple splice?
Your tail should be 50x the diameter, so in this case about 300 mm. And your taper should be 2/3 of your tail length, in this case the last 200 mm. Since it's 12 strand, divide 200 mm by 12 to get ~17 mm, Starting at 200 mm from the end, pull out one strand every 17 mm and cut it. I like to cut even the strand on an angle, and I pull it a few mm before cutting so that when the line stretches out again the cut end sits inside the remainder of the core.
I’m thinking about using this product for bow string replacement for my long bow and crossbows I was told that 3mm cord would be a good replacement I just need to find out what tool to use to form a strong loop and what loop would you recommend ?
not a climber here : but I use very often butterfly knot at sea and for dry land uses. I thought it was an alpine knot, is it not better than a bowline for Dynema? (NB had success with any type of rope i've used, even elastics(!) without seazing nor slipping ). Is it the bulk of the butterfly knot that is unpalatable?
What would happen if you moved the brummel to the bottom of the splice just before the taper? So, a standard eye splice, maybe a two fid bury, a brummel, then say half a fid bury and the taper of your choosing. I'm guessing it will break at the Brummel, but possibly you'd get the benefit of a standard eye splice with out the need to stitch and end up with some hybrid break strength somewhere between the two??? Just thinking out loud.
The first uses I know for Dyneema/Spectra was in sailboats and looking at their recomendations for splicing eyes.
But the one thing you can say is for climbing and splicing a sling/quck draw. Is the breaking strength is more then adquate for almost any method. Though I prefer the Brummel method.
Was wondering what was your intention of what are you going to do with your spliced eye slings in the real world?
cheers
I don’t know if this is real world but in this video we did an eye splice that if it failed we could have died ruclips.net/video/bG6X9NOzqm8/видео.html
And we put eyes in our whoopies for highline anchors and splice things for spacenets and I’ve used them in climbing as lightweight funkness devices
@@HowNOT2 1st thing I thought is most the splices held way over what any piece of climbing equipment will hold i.e 50kn. Only the open tail brimmed was below 15kn but still this is over a lot of slings.
But thanks as I an a gear junkie an ansl compulsive and way over engineer everything.
OK I've subscribed. You said tying a knot would be weak. My boat is attached to my winch with dyneema knotted with 2 x 1/2 hitches and 2 Cable (zip) ties securing the end. I would be interested to know the breaking force of a tied end.
I'd bet anything it slips way before it breaks
Hey you guys may be interested in a video from Ali Clarkson he has wheels on his trials bike laced with this stuff as opposed to steel spokes. He goes in depth into how you make them and do the splicing it’s very interesting if you’re into this kind of stuff.
I've heard of the bike with dyneema spokes
Hey what is that software you used to record and plot the data? What was the sampling rate?
Hi can u do a test how much u have to bury the tail so it doesn’t slipping out
How long should the taper be? And is that in addition to the 72 times the diameter?
Would a 3rd pass through /double Locking brummel improve the result?
Simpson ropes States in their manual That you told me to buy, that a woopy sling has 70% of the materials MSB. They also state they do their testing using eye splices.
Simpson calls out a longer taper.
Whoopies probably lose their strength because the adjustable part comes out all of a sudden and is way more reducing to strength than a bad taper
I was sure you were going to say "Test just the tip" and was ready with jokes,
I'll have to keep them to myself
Instead of stitching the tail on an eye splice to keep it from backing out, try misting the tail with contact cement like DuPont 77. Let it dry for a few minutes, and pull it through. The idea is not to glue it, but to make it "grippy".
Stitching is only intended for it to not come out when NOT loaded. Grippy against not grippy other strand is still slippery and should be buried at proper lengths.
@@HowNOT2 I'm aware of what the stitching is for. I am also aware the tail should be buried at the proper length.
what setup do you use for load cell? I want to put one on my rigging bench.
Could the splice being pulled out with a shorter buried section have to do with the size of the eye / the size of the object it's going around? (Because of sideways force on the knot)
In other words, would the shorter taper work better on a carabiner which has a smaller diameter?
interesting.
I think it would break it faster. Smaller diameter puts more force on outer strands of the eye and you can see a bunch of the eye breaking, even at that diameter. So a smaller bend radius could make it worse. I could make an entire video probably testing eye bend radius
@@HowNOT2 Then what about a bigger eye to match the bigger diameter, but keep the same length buried? Just to test the effect the eye size has on the strength of the knot.
I would like some of that stuff.