This is fantastic. I sail and rock climb, and really appreciate how much crossover there is. I think climbers often don’t appreciate how big the loads are on a big sailboat. Sailors think they are the only ones who understand knots. Both worlds have a lot to teach!
This is what’s known as a doughnut in the inland towing industry. I have made many of these out of 1 inch and 1 1/8 inch Amsteel Blue. Their strength is amazing. The only time I’ve seen one fail, it was intentional. But before it failed I thought the deck fittings were going to be uprooted.
Try the experiment again, this time using steel shackles to pull the Dyneema loop. The soft shackles apply radial forces to the Dyneema loop that are absent in the case of a steel connector (quick link, shackle, carabiner, etc.), and it seems likely that that is the root cause of the low break strength. I did an interesting break test on an aluminum arborist climbing ring some years ago, but couldn't fit two of my steel pulling shackles to the small ring, so I used one steel shackle and one small-diameter Dyneema loop for the pull. The ring broke well below its rated strength. Interestingly, it broke where the soft shackle had been attached, and was twisted and visibly crushed at the jagged break. There was only a barely visible dent at the opposite end where the steel shackle had been.
I was taught “soft on hard”, meaning connect webbing or rope to a biner, and avoid connecting biners to each other or ropes and webbing directly to one another. (Except yeah, biner goes directly on bolt hanger, and rope gets tied directly to harness).
Thank you for the straight torrent of factual information. As a 25 year tree climber, I am woefully ignorant of the cordage my life daily depends on. Great attention to detail. Great explanation. You guys are filling knowledge gaps across multiple industries. Thanks again.
thanks for the great vid! I climb and also happen to live on a 43 foot sailboat. I replaced all my lifelines with 3/16 dyneema, with 316 stainless closed eyes in the endpoints at the pulpit and pushpit..used brummel splices. I plan on doing all the standing rigging in dyneema. can't wait to see more of the marine equipment testing..
Yeah I'd like to see a break strength test between a friction joint like this and a brummel splice.... rigging doctor taught me to do a brummel splice loop but I kind of like this loop better if it's strong enough. The brummel splice loop requires re-braiding a bunch of the dyneema which is a PITA.
@@JR-kn6rs have you seen this method? ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DUSYUsWprc8.html No unbraiding then rebranding needed. I can’t attach a picture of my pull test of 8mm loop doubled inside a chafe cover pulled with a Ford F-350 and an aircraft tug (its all I had for a big pull). The F350 wheels in 4-wheel just spun.
Great video. David showed us a very cool way to end the safety stich of the Blue dyneema with a half-hitch and bearing the knot into the dyneema. Which is super cool and very clean looking. I will using that method from here on !.....I did notice, David started the safety stich with a stopper knot..... It occurred to me if we start the safety stich WITHOUT a KNOT but leave a tail. Once we finish the safety stich with half-hitch. We come back to beginning thread both tails through the eye of the needle make one more stich with half-hitch and berry that half-hitch into the dyneema.....for a super clean look on both ends of safety stich.... More for loops without a cover.....What say you ?
This was a great episode! And I would love to see this tested again with a wet soft shakel! That may keep the melting from happening so fast and increase strength further!
Very helpful vid! The tapering part was very useful, mainly how and where... I also love the wire fid, or the wire "nonfid".... Thanx, Balkan Shipyards
This is fascinating to watch! I'd trust splices made by David. As a climber, splices generally weird me out because they're handmade things that can't be inspected like a knot can.
Sean Monahan All knots reduce the strength of a line. A proper splice will retain near 100% of the original strength. Often exceeding 120% of the original strength. The failure point will be where the splice starts to change the natural lay of the line. That’s why proper tapering the splice is important. It’s just as easy to inspect a splice if not easier than it is to inspect a knot. Manufacturers warn against attempting to use knots in this type of line.
Great video. That is an amazing loop. I was hoping you'd cover sailing uses and cordage. (Maybe you have already). Brilliant result and very useful to know. Re: sewing the whipping cord to hold the bury in place. We had a big Para Sailor (brand name) kite at the front of our boat. It had four 10mm spectra lines with spliced loops (no thimbles). All of them eventually had 'rope a roids' (?) where the core worked out between the 12 strand cover braids. I just pushed it back in and made some very ugly stitches, same Robline as in this video. Seemed to work -- but I have no idea (1) if it was the best way to do this? Or (2) maybe I just created a more serious problem later. (These spliced loops were connected to the sail with a Dyneema soft shackle. These are used instead of something metal, or a bowline, so when the kite sail is whipping around it won't kill anyone.) Often when I see someone in a video using a fid, it's something I'd use a wire as David does in this video. I have some straightened stainless steel piano wire, 1/16 and maybe 1/32 that I just bend in half (very tight bend but I do keep some radius so it pushes through smoothly) And I prefer DIY wire. The ones sold by Harken have handles. These can get in the way. With bare wire if I need to pull hard I'll just use pliers or Visegrips. It's terrific that you're making videos on sailing. I showed up on board a sail boat with a lot of paracord, and carabiners. The sailors looked at it and scoffed. I had to leave several carabiners behind because they were performing important jobs.
That was super informative! I made loops for our rigging using a brummel splice. I wonder how they would measure up on the pull test? They connect the rigging to the chainplate (as a deadeye) and have carried us across the Atlantic twice so far!
It's either a fit a spike or an all however there is no reason you cannot use a needle. You use a fid to slip something into a braid, a spike to open a bind, and then in all to create an opening where there was not usually in the process of whipping and stitching. Needles are usually used for whipping and stitching however when you are pulling braid a needle is just as functional because you are only pulling strands to thin the braid. AKA any point will do in a pinch when you are going to cut the line at that point. And as I always think my ends I always pull one or two strands ahead of my cut and then sink it by putting it back through a few forward before cutting. When the tack is stretched the end will be sunk beautifully.
Interesting! I wonder if attaching the soft shackle round ring like the Petzl Ultralegere or similar ropeeye, to gain a bigger bend radius, is a nice way to increase strength of a connection. Just like it is on the thumbnail, btw.
FWIW, the wooden-handled fid shown in the vid is a 'Swedish Fid'. Another popular type is a hollow tubular s/s fid, often sold in packs of 5 graduated diameters/lengths, called a 'Selma Fid'. Then there are hollow DIY knitting needles and the barrel of a convention Biro without the innards.... for small stuff.
Being that dyneema doesn't stretch much, any radius of bend is going to load up individual fibers more highly on the outside of the radius. The closer to a shock load this will be, the more defined the area of load will be towards the outside of the bend. However, being that dyneema is incredibly slippery, the fibers will move under gentle and repetitive loads to naturally spread out the forces involved into a lot more equitable arrangement. It doesn't take much to see why progressively loaded or settled dyneema loops are so much stronger. What is happening at the macro level in the looped passes is also happening at the micro level in each bend. Dyneema responds to gentle conditioning, but don't we all? :D
I made 18-20' "mini-spansets" using the same idea but with tubular nylon as the sheath instead of dyneema. I made them so long intentionally so that I typically double or triple wrap the trees
Great video. Curious to know how a continuous loop of 1 piece of 8mm would have compared to the 3 passes of 3mm. Also, our continuous loops usually have thimbles or low friction rings sized to the Dyneema. Maybe, a test with your equipment connected to the Thimbles or Low Friction Rings would change the outcome. Maybe a protective Dyneema net over the top and leaving the room during the test in case shrapnel is created 😬
Loops like that combined with stainless sail makers thimbles are used to make deadeyes the turning radius matters and friction on the loop is reduced because the lashings are on the thimble not sliding on the rope itself. See kraken structures deadeyes.
My flash, these are deadeyes of the sail era, of hardwood they're easy to adjust the rigging on the lee side under way ... they have a larger radius so may be worth testing. Cheers 🍺
I usually use one Luke needle to pull three looped needles saving me both time and frustration, or I do it the hard way and work my loops one half at a time alternating. Simply anytime saving trick that does not sacrifice strengths or quality.
Have you you seen "GAC Flex" spansets aka liftall . GAC is short for Galvanized Aircraft Cable, which makes up the steel core of this spanset. Unlike traditional spansets with a polyester yarn core, these spansets withstand higher temperatures.
Any rearrangement of the strand stacking order in the bend will cause stress reassignment in the strands. I believe that spansets work better with Polyester or Nylon strands than Dyneema because of the very low stretch of Dyneema. Even if you could condition the loop by equalizing the internal stresses, the geometry will change when the loop is unloaded and especially if it is repositioned or flexed thus reordering the strands.
Most dyneema applications on sailboat are designed to minimize stretch (deflection) under load, which means actual loads are much lower than breaking strength of line used.
Cuba makes a very good pair of scissors that will cut spectra for about 4$. There is also a pair by Rapla that are 5$.. Both these scissors are for cutting spectra fishing line.
When you re tested the mailed in one, you didn't use soft shackles so the tests aren't comparable. I'd say test whatever they use on a boat? Great vid!
The boat gear used in each nitch application would be different. I'm Shure we could find an application on a boat that this would be the exact setup( 2 large shackles connected by a loop).
So are you saying there's not a chance they would apply the soft to hard rule in the boating industry and they're soft to soft was not a violation of this rule ? All indications are that the small bend ratios soft shackles + failure to "set" the knot was the failure mode . As well as the stated opinion of both people present at the original test. Did you notice in the pictures of the boating application of this device everything is protected with hard inserts that give a more favorable bend radius,and prevent braking the hard on soft rule?
@@daviddroescher no, I just know their intention was to test his boat setup! No test is useless, I was just pointing out the data is a little off since the tests weren't the same setup
Maybe you could share with David my suggestion to test the Jordan Series Drogue junction where 3 Brummel spliced eye loops ( the 2 bridle eyes attached to the boat to the lead section eye of the JSD rode) are girth hitched together. The Dyneema chafe cover would be a good variation to see if it prevents this heating effect between the 3 eye loops? Not sure how you could test it with the 3 lines fixed to 3 points, but if the 2 bridle eyes were one end & the 1 lead section eye the other end, is probably super good enuf. Gradual tensioning to let the dyneema fibers equalise in temperature would be very applicable to this JSD drogue use case as well.
So I think the stiching and taper of the internal loops prevents equalization. If it was preloaded (just bounced on?) with the splice stitch in place, but not tied off and buried, and UHMW tape was added between strands you would get super high breaks after a couple of low load pull cycles.
Yes herringbone is free-floating and stretchable where a running Stitch or a loop Stitch is going to rip shred and tear because you did not leave yourself enough sleeve to stretch your Loop. I know that at least my pack is going to be stronger than your attack because you're pulling shortcuts here and there. Personally I prefer making tax that looks like Nanobots bills it that way nobody knows where it starts or where it ends. Yes it requires you learn how to plait but once you know how to flat then the time that it takes is so minimal in comparison because your tack is so much stronger so much lighter and always passes inspection. And there's one more beautiful thing about my tax I always get top dollar because with my tax complete failures do not happen only a partial fail will happen before you replace it thereby saving the majority of your load. Yes I have to admit my tack will allow me to drop a barrel every now and again but I have never dropped an entire net, nor have I ever had a wild swinging load. Because ounce for ounce my contact will save your reinforced tack from a complete failure.
What’s the best place to source this kind of rope and materials? I tried looking for the small 2mm dyneema y’all showed in the soft shackle testing, but couldn’t find any on a quick glance of the inter webs. Any pointers?
Hey ryan, I'd be curious to see the forces that are taken by the bolt, anchor and climber in a lead solo fall, if that's something you'd be able to do once you get your drop up and running. Maybe with different devices like the grigri and silent partner.
Okay thank you very much finally somebody who builds tack the same way I do. Most people hold their houses together with nails and screws I hold my house together with dyneema tack and carbon fiber, dyneema, & Kevlar gel coats depending on the requirements. That is straps, belts, sheets, lines, and sleeves. With epoxy or latex rubber rosin. Never risking my gear to a single stitch. Okay not exactly the way I do things I'm going to be making stronger tack than you are making. However you're making three complete loops and then thinning your core as I will only use two before I send my core creating the Third with a chaffing sleeve pre-installed. And yes like you said it just takes practice to learn where it's going to find when it stretches. So I usually air on the side of extra links in the sleeve because I can always Stitch a sleeve as it is only for chafing protection. The core is always much less forgiving. And I am risking not only my life but my livelihood on every piece of tack.
You needed to put thimbles in your eyes on the machine you used to pull the loop apart so it doesn't heat up because of the bend radius being to small and heats up.
Man I’m the opposite I watch this video and I want to buy the stuff and sit at home with this video and learn how to make this stuff. Love this kind of rope work.
Using dyneema twine-thread for locking stitches isn't the best idea, especially without preloading first, for the exact same reason that using dyneema lines is a good idea. High strength, low stretch. When stitched through a non-pretensioned line or splice, the dyneema thread will resist proper 12-thread configuration within the main line/splice once put under load, as it traps down on itself. If the configuration is too misarranged when locked stitched...especially with a thread as low stretch as dyneema...the counterforce of the locking threads against the proper settling can lead to failure at the stitch points. Samson recommends nylon thread for lock stitching for this reason, and preloading of the splice prior to lock stitching can further mitigate this risk.
Any reason you refer to the piston as a " hydraulic"? The word hydraulic is used to describe a system "operated by a liquid moving in a confined space under pressure."
@@justinmeyerrwell, yes, but the hydraulic cylinder, or actuator if you will, is made up of a cylinder with a piston running inside it, so not really wrong to call it either, since both are parts of it. But yeah, in the industry we usually just call them hydraulic cylinders for sure.
I think the sheath was too tight and it pinched the cores. Would be nice to do the same with more slck in the sheath. Also do the same without the sheath.
If you have no choice but to stitch your core lines to keep them from sliding out of each other braid your stitches against all in houndstooth pattern amongst all of the lines in the rope in order to share the stresses equally and don't forget to zigzag when you are whipping and always I repeat always use rosin of the appropriate type in my case Sun baked milkweed latex as the latex rubber is a stabilizer not a strengthening comp and it is already UV protected by the sleeve. In addition I know my tax is stronger than yours because I do not burn anything no sharp edges to cut other lines and that is why I use rosin.
Okay I see why you're doing the stitching if you do the rosin then you might as well only pin. That will save yourself time and as long as you're not aggressive it will save abuse on your tack while you're building it.
