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  1. #111
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    Thanks for the "move".

    When making a continuous loop with a locked brummel (as depicted in my photo/post #109), the buries are in the opposite direction of a normal locked brummel as used in a fixed eye. I think this puts all of the stress on the lock and little on the bury/constrictor. I don't think I will use this method for weight bearing loops.

  2. #112
    Senior Member shumway's Avatar
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    That's where I was confused. If you bury the way it looks the neatest, it's weaker than the non-locked version. It may be physically impossible to have the lock and have the buries avoid that u-turn in the picture. I'm not describing what I'm thinking very well.

    OG - Thanks for getting this moved to a more sensible place.

  3. #113
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    I've done my loops according to Opie's tutorial and i have had no issues (I currently/ most recently use them as prussics for my Hennessy Exped). However, whenever I feel like I want the extra security, I make the buries longer. I'm at 7" buries for my new 12" loops (have a few at 8" as well) and I hung my full weight on hooks and bounced and so far no problems.
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  4. #114
    Senior Member opie's Avatar
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    Before I knew what I was doing, I was making things like this.

    The splice I show in the OP is called an "end for end" splice. Minus the brummel. Bury measurements are the same for an end for end as they are for a fixed eye. I added the brummel because it allowed me to pull the bury tails tight prior to burying. This let me get the bury entrance close enough to the brummel that it was near impossible to "accidentally" snag the bury and pull it out.

    Technically you can do the same thing minus the brummel, I just never did.
    I am not a gram weenie. , But Im starting to see the merits!!!

    Kris' Splicing

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  5. #115
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    Quote Originally Posted by opie View Post
    Before I knew what I was doing, I was making things like this...
    Some of use are at that "before I knew what I was doing" stage and a little slow to realize the wheel doesn't need reinventing.

    We'll figure it out someday.

    Thanks for sharing your knowledge.

  6. #116
    Senior Member DemostiX's Avatar
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    There are several remarks about tapering the bury in this discussion.

    Everything I find from the rope manufacturers and from the boating community says the tapers are essential if the rope / cord is not to be de-rated. I find some estimates of derating by as much as 50%. Contrary to the thought expressed in this thread that tapering is of the strands in the last 1/2 to 1", it refers to the pulling of half the strands, each strand at an additional increment from the end to form a smooth taper.

    The reason for the de-rating is familiar to me from well-documented metallurgical failure in bicycle parts in anything from the frame tubes to crank arms: "Stress risers" are just what the rope engineers refer also refer to. (eg. To collapse a bicycle down or seat tube, drill a couple of holes in one to mount another water bottle. There will be stress risers, from which cracks will emanate at those holes.)

    So, you want to avoid any sharp discontinuity such as where the bury ends, by tapering it I don't know what Amsteel and similar looks like when it fails, but I can guess that most of us are not carefully examining our cord and rope, the way the nautical, arborist, climbing, and rescue types do. The best policy is to make splices the way the pros do, even if we don't have the experience of seeing failures in the field from the many more exposures to failure in harbors and other places where there is a lot of rigging.

    This Samson Rope video is pretty clear on the taper, by using serious rope.

    http://samsonrope.com/12-strand-class2-eyesplice.cfm. Go about 40% in to see that creation of a taper in the bury.

  7. #117
    Senior Member opie's Avatar
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    Quote Originally Posted by DemostiX View Post
    There are several remarks about tapering the bury in this discussion.

    Everything I find from the rope manufacturers and from the boating community says the tapers are essential if the rope / cord is not to be de-rated. I find some estimates of derating by as much as 50%. Contrary to the thought expressed in this thread that tapering is of the strands in the last 1/2 to 1", it refers to the pulling of half the strands, each strand at an additional increment from the end to form a smooth taper.

    The reason for the de-rating is familiar to me from well-documented metallurgical failure in bicycle parts in anything from the frame tubes to crank arms: "Stress risers" are just what the rope engineers refer also refer to. (eg. To collapse a bicycle down or seat tube, drill a couple of holes in one to mount another water bottle. There will be stress risers, from which cracks will emanate at those holes.)

    So, you want to avoid any sharp discontinuity such as where the bury ends, by tapering it I don't know what Amsteel and similar looks like when it fails, but I can guess that most of us are not carefully examining our cord and rope, the way the nautical, arborist, climbing, and rescue types do. The best policy is to make splices the way the pros do, even if we don't have the experience of seeing failures in the field from the many more exposures to failure in harbors and other places where there is a lot of rigging.

    This Samson Rope video is pretty clear on the taper, by using serious rope.

    http://samsonrope.com/12-strand-class2-eyesplice.cfm. Go about 40% in to see that creation of a taper in the bury.
    Yup, thats the proper way to perform an eyesplice according to Samson. Who has a legal team directing them to CYA in any way, shape matter or form they can. Liability and all that.

    Check this one out...

    http://www.samsonrope.com/site_files...plice_2008.pdf

    I sent a question off the Samson asking why they show a locked brummel splice with the taper consisting of just cutting the end at an angle, while an eye splice being 3 fids with the taper being pulling half the strands 1 fid in.... The response had a couple points...

    First was that the whoopie sling has the majority of its derate at the exit point for the adjustable eye bury, so any derate from the "lack of taper" (if you want to consider it that way) is a moot point and negligible.

    Second was for legal reasons.

    I think you'll find, at least I have, among folks who actually use the rope, the cutting of the end at an angle yields sufficient results with no great loss in strength, if any. I haven't seen a practical splice yet that will place a 50% derate on the rope. Don't get knot derate and splicing derate confused. Even Samsons suggestion of 40% on a whoopie sling is very generous. Ive found a 7/64 sling to retain the majority if the lines average strength. Same with Dynaglide. All using an angle cut for the taper.
    I am not a gram weenie. , But Im starting to see the merits!!!

    Kris' Splicing

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  8. #118
    Senior Member DemostiX's Avatar
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    There have been remarks, by senior members in these threads, essentially dismissing what is best practice by pointing out they're still alive to post the message. Most good practices are NOT because risk-averse lawyers say so. This isn't about reducing wear and differences in working load, but about preventing easily avoidable catastrophic failure. Same holds for putting the several stitches in a splice to be sure that when there is no load the core and constrictor don't move.

    There'll come a time, with increased numbers of hammockers, that someone is seriously hurt because a sling that could easily have been made correctly fails because it wasn't. More serious consequences than of a poorly sewn hem, or falling one foot to the turf in a back yard. And this isn't about whether the safety factor on maximum strength should be 3, 5, or 7. It is about whether we have tested the stop knot in a lovely soft shackle by loading it to near rated maximum for a day to confirm the stop knot in dyneema doesn't slip before making a gift of it.

    To Opie and the other rigging and rescue pros here: This isn't directed toward them. I'm enjoying magic with rope as much as the next person.

  9. #119
    Senior Member opie's Avatar
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    Demo, had a reply all typed out, but it got way OT.

    In short... The proper measurements and procedures for making slings and whatnot are all over HF. It would not be the responsibility of anyone but the person making the sling if its made incorrectly. Even links back to Samsons splicing pages are strewn about HF.

    I havent yet seen anyone suggest to anyone else to NOT stitch a plain fixed eye. To the contrary actually.

    It is not industry standard to load something "for a day" to test it. Sure there has been some backyard destruction around here, myself included. The world revolves around taking something and making it better. This means sometimes one needs to push the design specs a manufacturer sets forth. Samson does not have a splicing page for a soft shackle, yet people make them and they have been tested and hold up.
    I am not a gram weenie. , But Im starting to see the merits!!!

    Kris' Splicing

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  10. #120
    Senior Member DemostiX's Avatar
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    Here are general recommendations for single braid UHMWPE line such as the Amsteel we are using, by McCarthy and Starzinger from US Sailing.

    The source is a pdf [/URL]from January 2010. They present it to reflect collective wisdom and experience from multiple communities of users over a number of years.

    I've hi-lited a few points that were new to me, if not to you.

    As in all line, splices are preferred to knots where possible. As with all line, a splice in Spectra® will be stronger than a knot. Generally a splice will be 90-100% of the line strength while a knot will be only 55-60% of the line
    strength (excluding the slippage issue discussed below).
    There are two splices in common usage with single braid Spectra®: the locked Brummel
    (http://www.neropes.com/SPL_12Strand_...ceBrummel.aspx) and the Bury
    (http://www.samsonrope.com/site_files/12S_C2_EyeSpl.pdf ) . The Bury is perhaps the simplest of all slices in all types of line. After making it once with instructions, most people can make it again without instructions. This splice
    must absolutely be lock stitched or it may slip under low load. With lock stitching it is absolutely secure. The locked Brummel is more complex and many people will require instructions each time they make it. In return for this complexity, the locked Brummel is more secure (without lock stitching) against low load slipping. However, if the buried tail is too short on a locked Brummel, the whole load can come off the ‘knot like’ locking portion and it will break at much lower than expected load. Recent testing indicates the buried tail must be 72 times the diameter of the line, which is longer than previously recommended and typically used in practice. Both splices are acceptable, but the Bury splice is simpler and more resistant to improper construction, so is generally used.

    One key to proper construction for both splices is a long smooth taper on the buried tail. If the tail is not tapered it will create a stress riser at its end and the splice will fail at that point. A second key to proper construction is that
    Spectra® is more slippery that almost any other fiber and splices can slip at quite low loads if there is an oscillating or jerky loading. To prevent this all splices should be lock stitched and the throat whipped.

    The document goes on to describe (even untreated) dyneema as among the most abrasion-resistant fibers -- that's to you, Grizz --saying that the best protection, if needed is more dyneema, and that signs of abrasive wear are obvious: fuzziness.

    There is also this suggestion I think we have not seen before here:

    Knots should have the tail lock stitched to the standing part as this will eliminate the risk of slippage. To untie these knots you can pull the tip of the tail away from the standing part and slice the lock stitches with a razor blade.

    Dunno that many campers will whip out a needle in a pinch to inject a few threads, but there it is.

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