A concern about the Arborist Splice

[NickfromWI]

Ron, are you still talking about arborist rope? The rope IS spliceable on both ends. There is a risk, though. If you think about how the friction hitch reacts on the rope, if you were to descend 60' out of a tree on a 120' rope, when you got to the end, your friction hitch would have milked 120' worth of slack and sent it into the splice on the tail end. You know that splice is a delicately balanced act of tension, and now you messing with all that, risking loosening the splice, and you can figure out what happens next.

love
nick

[RonReese]

Originally Posted by NickfromWI

Ron, are you still talking about arborist rope?...

Well this thing has kinda "moved" from the orginal inquiry, but I've learned a lot and hope it hasn't been too much of a drift.

Nick, I think the answer to your question is yes, but there is arborist rope and then there is arborist rope. To wit: Arbormaster is a 16 strand with a unique splice for that type of rope construction. Velocity is a 24 strand double braid construction arborist rope but it uses a different splice than ArborMaster type ropes.

But, both of these ropes are advertised as simply spliceable. Other arborist ropes, such as ArborPlex, and some others, are listed as not spliceable at all. Yet other arborist ropes, such as New England's Fly, Samson's Yellow Jacket, Yale's XTC series, Wall Rope's Pro Stripe and Pro Spec are listed as, and I quote from SherrillTree's catalog, "Spliceable (eye, 1 end)"

So I was wondering why some ropes are spliceable, period, and some are listed as, "Spliceable (eye, 1 end)"?

Are the ends different somehow?

Does "Spliceable (eye, 1 end)" imply that if you cut off 4 -5 feet of the rope from the spliceable end, it now becomes unspliceable?

Originally Posted by NickfromWI

...if you were to descend 60' out of a tree on a 120' rope, when you got to the end, your friction hitch would have milked 120' worth of slack and sent it into the splice on the tail end. You know that splice is a delicately balanced act of tension, and now you messing with all that, risking loosening the splice, and you can figure out what happens next.

IF the splice is properly secured with stitching or whipping, the milking should stop at the stitching or whipping. I think that is the quintessence of the importance of a properly secured (stitched or whipped) splice. I.e. it protects the splice during no loads and adverse handling conditions such as milking.

However, in a double braid splice even if the splice had not been stitched, while it wouldn't be a desireable condition, I don't see that the milking issue would necessarily lead to a catastrophe since the final step of the splice is to bury the cross-over via milking. Certainly the eye would become smaller IF the milking was forceful enough to force the cover over more of the splice. But when force was applied to the eye, it seems like the rope would simply adjust to a smaller eye, or back to near it's original size. But that's just an opinion, that is not backed by experience.

But, it is somewhat of a moot point, since I think the one thing we all agreed on from the start, is that all splices should be secured by stitching or whipping.

And Nick, I saw where you posted this on another forum.

Originally Posted by NickfromWI

."Ron, we're on the same page. Stitching DOESN'T make the splice stronger. It makes it more secure. In some of the break tests I've seen, the whipping is the first to go, when the rope is really pushed to the max, because sometimes the splice "adjusts" so that the cover/core are holding the load equally.

Will some one get me a rope-breaking machine for christmas?"

I thought that was very enlightening and took the liberty of quoting you here. If you have any objection to that, I will remove it immediately. But I thought it was very mcuh worth sharing.

And I'd like to have rope testing machine too. But maybe I do. We actually have a 20,000 pound tensile machine here at school. We're waiting on a repair and it should be good to go, but, there is some question if the machine will have enough "stroke" to accomdate the length of a splice. And, of course I'll have to come up with an anchor for the other end.

[RonReese]

I talked to Samson about their Yellow Jacket rope [Spliceable (eye, 1 end) ] and they referred me to Sherrilltree. It seems that Samson makes Yellow Jacket rope as a proprietary product for Sherrilltree. Sooo, I called SherrillTree.

Purportedly, the issue lies in the relationship of the cover and core. The rope is uniform throughout and can be spliced at either and both ends, BUT it shouldn't be! The reason given was that milking of the rope could cause a problem for the spliced end. I have to be honest, I think the answer raises more questions than it answers. For example, I asked what stops the milking with one eye splice? That seems reasonable to me. They said a knot would stop it - what knot? I.e. if one end of the rope is connected to an anchor point via a knot, will it not still milk toward the splice? Well, yes it would; just as much in fact as it would if it were connected via an eye splice. I asked what keeps the rope from milking with one eye splice? Well it goes off the end of the rope. Does that process never stop? Will the cover continue to milk time after time?

Anybody?

[NickfromWI]

The milking does stop, usually after the first few long descents. When I get a new climbing line, I purposely just climb on it up a tall tree and descend on it 4 or 5 times to just get it over with. Some people whine a lot about the milking and consider it a sign of bad rope building. It doesn't bother me any.

If a person wants an eye on BOTH ends of a climbing line, I wil splice one side, climb on it a few times, milk the foot or two of cover off, then splice up the other end. If the person is nearby, I'll give it to them to climb on for a few weeks, then splice it after that.

If there's one splice, you've never really milking TOWARD the splice, so you aren't risking making that one looser.

love
nick

[Dan Lehman]

Originally Posted by Brion Toss

The most recent one was on some 5/8" Vectran, as I recall, and it broke in the high 90's

Actually, this raises another issue: Cordage Institute standards required that conforming
vendors use splice strength AS the material's tensile strength; they made some bit of noise
about this in contrast with methods of calculation used internationally. Naturally, this begs
the question as to real rope strength, what with some particular splice being as it were
defined to be 100%!
(This is mentioned e.g. in that Practical Sailor Sept 2001 issue carrying their purported
re-testing of your Sail article's alarm about knots being so weak in hi-mod cordage.
--that great testing with Aramid Rigging, seemingly somewhat associated w/Yale, who "knew
a trick or two" about dealing with the new-fangled ropes, but whose eye splice(s) in Yale
Light pulled out before a Bowline broke !! And then they reported THAT value in the table!)
So one question is whether vendors are following the CI recommendations on advertised
strength.

You ask how invisible stitching could hold well.

Rather, I asked how such simple back'n'forth few strands of stitching such as I've seen
recommended could hold well. Re "invisible", I simply asked What's that? The Grizzly
stitch splice I think has many bindings of a braided core, and is somewhat more of a
seizing between two rope parts. I don't see a single yarn going through cordage
as finding much purchase with which to hold.

And I believe you are mistaken in saying that stitching puts less material into the rope; a whipping has 6 or 8 frapping tucks through the rope, and sometimes only 2, whereas one can stitch as many times as one wants -- though I usually say 6 to 8 is fine. Not only that, but those stitches can be made at a wide variety of angles, and can travel linearly and radially, intersecting the core in more places.

Actually, I don't see a whipping putting ANY material through the rope, but as tightly
compressing it. Again, I mostly whip small stuff (3-12mm), and prefer to haul tight an
Extended Strangle, or French (and was just playing around with a sort of doubled
half-hitch in that--a structure presented by Geoffrey as a decorative hitch, but which
has some appeal qua whipping). This ExtStrangle has an extra crossing of its ends, and
enough wraps to cover, and usually a finish of one end with a sort of Common Whipping
or Blood Knot binding (the end being a tucked bight, initially done to not have to size and
waste the whipping thread!). Give a few squeezes with pliers during tightening, which my
belief (hope?) is helps distribute tension at the hauled-tight ends into inner wraps.
And, again, all this for a low-load squeeze when finger-trap sheath squeeze hasn't risen
to the task.

As for inspectability, again, why would you need to inspect it, any more than you would need to inspect the "invisible" buried rope tails?

Because this stitching is only a few bits, and breaking it somewhere makes for a big loss,
percentage-wise. Assuming that the splice gets beat up enough there, you might not so
readily see that the stitching took a hit; no way can something be happening to the core,
and if whipping suffers greatly, that will be obvious. Again, for use by arborists where the
splice is in plain, frequent view.

And yes, you could say that the splice is stronger than the rope, but then you could say the same thing about a Bowline or any other knot

And this could be tested by ... ?! The claim has been made; e.g., On Rope 1st ed.
carried some caver's claim for the Triple Fisherman's Knot. But this surely resulted from
a naive testing & interpretation of results. You have to transfer load from the rope to the
additional parts of a knot or splice, and that takes friction and isn't going to multiply the
load bearing.
Sometimes angler's knots are given high claims; this comes from using rated vs. actual
tensile strength (of which there can be a huge discrepancy in esp. gel-spun lines!!)

For instance, for years I was emphatic about the need to taper any splice. And it almost always does make a significant difference in rope strength, as well as being less likely to chafe than a square-shouldered finish. But destruction tests on 3-strand ropes consistently showed that untapered splices were stronger.

I'm interested in exactly how the competing splices were made. E.g., if it's the case that
the taper began at a point where the untapered splice simply ended, one might speculate
that the tapering simply aggravates a build up of torsion in the strands. As opposed to an
engineering principle of If it breaks, take some material away from it (well, that's a bit
of the rule in swaging bicycle spokes.) So one might thus back out one strand 1, another
2, tucks, and yield a by-strand aka West Coast/California taper!? (some of the eyes on the
Cape May - Lewes ferries have 3-4-5 tucks in this way, with a common start; using that
Pro-Splice start I think puts one 1 tuck ahead in one strand and you'd have 3-3-4, etc.)

Thanks,
(-;
[now to see if the system wants to ID me yet again (yep)]

[RonReese]

Originally Posted by NickfromWI

The milking does stop, usually after the first few long descents. When I get a new climbing line, I purposely just climb on it up a tall tree and descend on it 4 or 5 times to just get it over with. Some people whine a lot about the milking and consider it a sign of bad rope building. It doesn't bother me any.

If a person wants an eye on BOTH ends of a climbing line, I wil splice one side, climb on it a few times, milk the foot or two of cover off, then splice up the other end. If the person is nearby, I'll give it to them to climb on for a few weeks, then splice it after that.

If there's one splice, you've never really milking TOWARD the splice, so you aren't risking making that one looser.

love
nick

Nick,
That makes sense and that's why I wondered why some ropes are listed as spliceable one end only. Looks to me like the process you just described makes splices in both ends feasible. But the guy I talked to at SherrillTree, seemed pretty confident that the problem with the one end only ropes is that some how the core and cover could slip/milk - I don't know, sure didn't make any sense to me.

I'll probably call some other rope manufacturers (Yale and New England) and see what they say about their ropes that are purportedly spliceable only on one end.

I can't see why one couldn't do exactly what you described and have safe splices.