A concern about the Arborist Splice
 

Iím new to braided rope splicing, but I have done 6 eye splices in Velocity rope following Samson Ropeís instructions. They work and look good. After watching Brionís splicing video, I now know how to make them better ñ a special thanks to Brion for taking time to make a video on splicing.

Getting to my concern, I made my first eye splice in ArborMaster 1/2î rope. ArborMaster is a braided cover with a core of twisted strands. I watched Brion Tossís video where he spliced an eye in New Englandís Safety Blue rope. Safety Blue looks like it has the same or at least similar construction as ArborMaster.

To make a long story a little shorter, by the nature of the arborist splice, the core and the cover overlap inside the cover well down the rope away from the eye. Thatís what concerns me - the overlap. The overlap of the cover and core, inside the cover, seems to me, produces a weak spot in the rope. At the overlap, I presume part of the strength at the overlap is supposed to come from the overlapping core and cover strands and hence, presumably the overlapped strands have nearly the same strength as the non-spliced rope. At least thatís what weíve been told ñ a splice approaches the full strength of the rope.

But if the overlapped strands can slip at all, load is transferred to the cover. I suppose there is the Chinese finger trap action of the core at the overlap, but even with that if there is ìthinningî of the core due to a slightly insufficient overlap there will be a reduced cross sectional area and it seems like that would produce a significant reduction in strength.

Thoughts?????

Thanks,
Ron

Hello,
Excellent question. On some ropes, like Sta-Set-X, all of the strength is in the core. An overlap splice in that rope would have some strength, but not enough; that's why the X splice is the way it is. But in arborist and similar ropes, most or all of the strength is in the cover, and the core is there to keep the rope round. The overlap is meant to maintain constant diameter, not to contribute to strength.
Note that some arborist rope, like Fly, has all the strength in the core, even though the construction looks the same as cover-strength ropes. So as with any splice, make absolutely sure you are doing the right splice, before you pick up your tools.
Fair leads,
Brion Toss

Thanks, Brion. That's a relief. If the cover is the strength then my concern goes away.

Here's a link to three pics of the splice; you can't really tell much, except that its a splice.

Since I made the pics, I have stitched the base of the splice. I'm considering whipping it as well. I noticed your DVDs don't show a whipped or stitched splice, so I'm a litte foggy on what constitutes a good whip on this splice. Suggestions?

P.S.
How important and what is the purpose of stitching and whipping eye splices? Also, which is better, stitching or whipping?

Thanks,
Ron

Splice pics (three) - Some pics of Velocity splices as well (among other things):
http://www.combatcarry.com/vbulletin...ad.php?t=16495

Stitching
 

Hi again,
I mention elsewhere in the video that I much prefer stitching ó and invisibly stitching, at that ó to whipping. The purppose of both is to hold the splice together at low loads, when the "Chinese handcuff" effect is weakest. Whippings look emphatic, but they typically engage the interior of the rope minimally. This leaves the support largely to compression from the round turns. This seems less effective, as well as being vulnerable to chafe.
Because the cover is braided, stitching between surface yarns will always engage the layer underneath. So you can stitch invisibly, but still tie the core to the cover, with no chafe vulnerability. Plus I think it's more elegant.
Fair leads,
Brion Toss

Thanks again, Brion. That's the way I see it as well.

I don't see any way to do a PM (private message), but I want to say this, so I'll take a bit of liberty to say it here:

I've been teaching at a community college for almost 20 years. I know good and bad "teachers" almost as soon as I see them in action. One of the things that good teachers do is break down complex problems to a logical sequence of less complicated steps. Another thing is they have insight to the "student's" perspective and knowledge base and work from that level. Good teachers have a way of gaining students' confidence and projecting the idea that "they" can do what their being taught. Probably most important of all is the hard-to-define talent of transferring knowledge. I believe this is one of the main things that separates excellent teachers from good teachers.

You exhibit all these things, and more. You clearly are a gifted instructor. I also enjoy those subtle humorous comments you make during the presentations, one for example, describing the enlarging of the core diameter from burying the cover/core inside the cover - "...it gets shorter and fatter, like we all do....". I could go on but, suffice it to say, WELL DONE!

What should we consider "low loads?" I like to pull on the eye of a non stitched single braid rope at various angles to see how quickly the handcuff action starts. What we do know is that the grabbing on doesn't happen immediately, and an arborist splice on the end of a climbing line is constantly being loaded and unloaded. Many times a day it sees those "low loads." Stitching or whipping is ESSENTIAL here.

We need to come up with a term for that "chinese handcuff" effect.

love
nick

Nick,

Just so there's no misunderstanding, I'm not implying that stitching or whipping are not essential. I just want to be sure that the strength of the splice (not the security of the splice) does not depend on stitching.

I would be horrified to think that the support of my weight ( or more) would be dependent on how well and with what material an eye splice was stitched.

I have tested an unstitched, unwhipped eye splice in Velocity rope at 600# and it didn't budge even a fraction of an inch under repeated loading and release.

What I hope is true is that the strength of a splice is in the splice per se, not the splice plus stitching. I'm hoping that the stitching is there just to keep the splice from being inadvertantly pulled or worked loose at no or low loads.

Ron

If you're concern about the splice strength is for the end of a climbing line,
then I'd think you need little concern (for maximum strength), as that needs only
so much strength (how strong is your body, e.g.?!). What's important is the eye
staying an eye (and not, er, winking or something); and doing so always.

!? I don't see how a few bits of cross-woven (stitched) thread/yarn so much holds
together collections of fibres: afterall, it's not as though one is impaling some solid
object--rather, the stitched lines run through (very small) space, strictly! And being
few and with minimal surface (sheath) contact, they can only generate so much
compression. How (much) does the Chinese finger-trap squeeze effect engage the
interior of the rope?!
Whereas with whipping, considerable compression can be generated (which, remember,
is supposedly only needed at "low" loads--not when considerable tension might so
elongate the material as to effectively reduce compression by reducing the bound
diameter). As for chafe, that depends upon material & usage; in the case of the eye
of a (tree) climbing line, it's readily visible/inspectable (unlike some other applications).
(Some 60-100# monofilament fishline & extended Strangle knots can make for a tough
binding.) How really safe from chafing can stitching be--as it too comes to the rope
surface (in small quantities)? If it's so "invisible", how will you know if it's intact?

--dl*
====

I'm concerned about how to properly perform and terminate an eye splice in a rope. A properly done splice purportedly retains 90% or better of the rope's strength and I want to get every bit of the strength out of my splices I possibly can. We could ask why ANSI sets a minimum strength of 5400 pounds for an arborist rope, when all it's likely going to support is 200 pounds or so, AND that 200 pounds is often supported by two ropes giving a minimum strength of 10,800 pounds of rope strength.

A splice is a lot of trouble to put in a rope, so I might as well maximize the splice if I can. Samson Rope recommends stitching to terminate a splice in double braid and whipping for 16 strand such as the arborist splice. They actually test splices on their tensile machines so I presume they've tested all this. Maybe it doesn't matter a whole lot either way because it's only to hold the splice together rather than to enhance strength. Or maybe stitching is better in double braid and whipping in 16 strand.

From the Samson Rope website (double braid):
Procedure for Lock-Stitching Eye Splices
Stitch locking is advantageous to prevent no-load opening due to mishandling.
Material Required: About one (1) fid length of nylon or polyester whipping twine
approximately the same size as the strands in the rope your are stitch locking.
The same strands cut from the rope you are stitch locking may also be used.

16 strand:
Step 8b - Apply whipping to base of eye for a distance of about 1-inch
or 2 rope diameters.

I just spoke to Sherrilltree. They whip all their splices. They unhesitatingly said that the whipping only adds protection against the splice being inadvertantly pulled apart under no load. They also said that whipping or stitching adds no significant increase in strength to the splice.

11:00am EST - I just spoke to a splicer at Samson Rope. They really prefer stitching. He said that if you whip the splice, be sure it's the whipping method that passes through the rope as well as around it. Also he said, without any reservation that the stitching/whipping is only to keep the splice from coming apart under no load.

I looked at Yale Cordage's splicing instructions. They recommend whipping finished with what looks like two stitches over the whipping.

New England seems to think both is best.

Harnesses and webbing loops both rely solely on stitching and the stitching approaches the strength of the webbing.

Just to be clear, I'm not asking should a splice be stitched or whipped or nothing at all. I consider it a given that the splice will be secured with either stitching or whipping. What I was asking orginally was the purpose of the whipping and stitching. It seems that the stitching is to prevent the splice from being pulled apart under no load/light load conditions due to miss handling, etc. They actually don't say that whipping 16 strand serves the same purpose as stitching in double braid, but clearly a method of securing the splice is certainly called for. I now wonder if stitching is better for double braid and whipping is better for a 16 strand braid, or if maybe Samson has gone to stitching and just haven't updated their instructions.

Stitching
 

Hi again,
Dan, neither stitching nor whipping will add significant compression to add to the handcuff effect. Whipping might apply more, but even if so, whipping can be chafed away. In any event, both methods provide security through shear strength, not compression.
As for how we know if invisible stitching is intact, you may as well ask how we know if the buried tail of the splice is intact; of course they almost certainly are okay, as they can't be chafed externally, or degraded by UV. That leaves chemical corrosion or grit causing internal chafe, and those can be prevented/watched out for.
Whipping 16-strand might seem more attractive than stitching, as the looseness of the weave gives less "bite" to the stitches. Even so, I find that stitching is neater, chafe-proof, and easier done. You just have to be a bit more careful about it.
The strength of arborist rope might seem needlessly high, but there are a couple of compelling reasons for it: shock loads can easily multiply a person's weight (which could easily approach more like 300lbs at times, what with all the gear that arborists take aloft); and the factor of safety had better be at least 10:1, as arborists typically do not use secondary support lines, so must get their redundancy by other means.
Finally, I think Ron is exactly on in saying that it is a given that the splice will be either stitched or whipped. Or both. And by the way, the stitching will also keep your splices from floating apart in a washing machine...
Fair leads,
Brion Toss

Cover slack removal in the eye...
 

For the life of me, I can't seem to get the slack out of the cover in the eye. The eye looks pretty good, but when I "milk" the cover in the eye from one side of the eye to the other, it bunches up some. Boy that's frustrating! I thought I was keeping tension on the cover and the core as I buried them, but something's happening.

Since I haven't stitched it yet, I presume it's possible to "unbury" and re-bury and try to deal with the tension better??????

Ron...you're not talking about the 16 strand splice any more, are you? Sounds like double braid probs to me.

When there's a tiny bit of tension, is there still excess cover? If so, then there's a prob. If it only happens when the eye is slack, that might be normal...I'd have to see it. Just think how rope can be milked when there's no tension on it...is it like that?

love
nick

Duuuhhh...Sorry I switched gears and didn't even realize it #$%#
 

Very astute, Nick, of course from your posts that I've read, that's pretty SOP for you.

I'm sorry, I was splicing Velocity again, which is double braid. I "unburied" the splice and re-buried it. I had to use one of Brion's tricks of "skewering" the rope and pulling out the slack. I think I finally got what I wanted.

Impressive insight Nick, I think that's exactly what's happening - well now anyway. I think before I tightened it, the cover did have a bit of slack in it, but it's better now. I think you're right; it does seem to be a normal milking thing.

Maybe I'm thinking of a different whipping than is commonly employed?
Tying extended Strangle or perhaps (Dbl.) Constrictor knots in strong material enables
a good deal of tightening to be done (a man can easily pull with 60-100+ # force on the
ends). This I'd think would give good assurance against low-load shifting.

What is "invisible stitching"? Don't you have to bring the thread to the rope surface both
as a methodological necessity but also in order to bind the sheath--the point of it?! And
if so, then that thread's vulnerable. (As for knowing about the bury, well, what possibly
can happen to it?)

Indeed! And the answer might be something like learning how sausage is made, not
terribly attractive. I think that Tom Dunlap (arborist) and some others have some insights
to some of the motivations behind some rules, and IIRC, they don't all seem so compelling.

Ah, not with diet, then. :D
Or maybe durability was part of the formula. (Paolo Bavaresco found some interesting
diffferences in residual strengths of various lines--some seemed to lose a lot, others not
so much.)

--dl*
====

ps: I seem to be queried for re-logging in a many steps en route to making a post,
even though I logged in once or twice (or ...) previously and got the jolly "Hello, Dan Lehman"
greeting!? Homeland Security in on the operation?

It is claimed that splices retain up to 100% of the rope's strength. That kind of strength retention, as explained by Brion, SherrillTree, Samson Rope, One Rope 1, comes from the integrity of the splice rather than the whipping or stitching method. Most seem to readily admit that whipping/stitching only serves to keep the splice from slipping at very low or no loads or from mishandling.

If the splice itself maintains nearly 100% of the rope's strength then a good, strong, tight whipping or the best stitching isn't going to make it 110%.

In fact, such tight whipping could diminsh the strength of the splice by creating stress concentration at the whipping. This is a commonly known phenomenon in structural materials and design.

I would think that stitching does expose a small portion of the thread to abrasion, but whipping is totally exposed, 360? around the splice. But it's a bit of a moot point since the stitching/whipping does not add strength to the splice.

LOL! Well maybe. But I like sausage, and whether the means is attractive or not, doesn't change the palatability of sausage.

But really, we're just expressing opinions and I'm not sure what those opinions are based on. In my field, engineering, I commonly see things being done a certain way because they've always been done that way and nobody knows any other reason for doing it that way.

Sometimes that approach is successful, but in some cases it breaks down because it's been a bad practice all along, and nobody knew it until it showed up one day.

FOR EXAMPLE - I was hired to interface a computer to a fire test laboratory. They test the flammability properties of all kinds of materials. The idea was to computerize the data collection and calculations which I did. Well, except for one calculus based calculation which I had worked on for hours and couldn't get the same answer they got. Finally, with the "top dogs" and technical staff present, I asked them to show me how they calculate this one parameter. As soon as they showed me, I took a deep breath and said, "You know that's not correct don't you?" They didn't even hesitate to admit that they knew it was inaccurate, but that's the way they had always done it. I asked what they wanted me to do and they said make the computer calculate it the way we do. I was done in five minutes and they were happy.

So until we put our splices and stitching and whipping opinions and/or practices to a real test on a tensile machine, we're just doing what we think makes sense to us with little support other than our experiences in the field that may not ever approach critical loads like a tensile machine would.

Would you guys splice some things, then whip and stitch in a variety of ways to have them sent to me and broke tested?

love
nick

I'm interested.

1- What kind of machine will you be performing the tests on?

2- In addition to testing whipped and stitched splices, could I persuade you to test some splices that haven't been stitched or whipped? Or, have you already done that?

3- How much rope do you need per splice?

4- Could you test a splice in each end of a rope? As I think about that though, that would place a heavy load on the rope - twice and the rope may fail superficially.

5- How many could I send you?

Since a splice has a larger cross-sectional area than the rope, it almost makes you wonder if the splice could actually be stronger than the rope????

Lots of things are claimed, but often those claims are shown to not hold water. IIRC,
a recent arborist posting about a new "Grizzly" stitch-splice (eye) revealed a vendor claim
that it was stronger than a splice in the same material (so obviously that splice wasn't
100%). But I've not said that whipping was supposed to replace the splicing, only that it
seemed a better/surer method to guard against low-load (and otherwise) shifting. Yes, it
IS exposed--precisely my point about its inspectability, and also re use in an application
where the material is readily viewed--, but the adjacent turns of tight whipping resist
abrasion pretty well. Compared with something called "invisible" of much less material,
it seemed preferable.
Yeah, it might be that in a pure one-time break test that the point of whipping becomes
the point of weakness; on cyclical non-break loading, it might be that an unwhipped splice
yields, ultimately, whereas the whipped one endures. And which testing more accurately
models usage? You should be nowhere near the break strength in use!

And partly that's why I sometimes raise a question--to try to learn, to see the rationale/basis.

Again, the tensile machine is one measure of one aspect and not likely the most important
one. The Fisherman's knot is common in commercial-fishing/-marine use; on the tensile
machine, many other bends will test stronger, but after several months of usage, the other
knots might well suffer more damage from being knocked about, run though pot haulers,
whatever, and tested X months later, not fare so well. So, which knot was "stronger"?

----------
Nick, to your testing offer, we need more details:
1) what size specimen, & how constructed (e.g., eyes at each end, 4-7' span)?
2) where to send (etc.) (who's doing the testing?)

I don't expect to splice anything like above, but I might like to see how a seized eye tests.

Thanks,
--dl*
====

Reinventing the wheel?
 

Hi Dan,
My apprentices are currently preparing some splices to be destruction-tested. We do that sort of thing fairly frequently. We have also run cyclic loading tests on occasion. I would be happy to send along the results. This next batch will be broken by New England Ropes, but you can likely find several test facilities in any major city. Typically the samples should have at least 5ft. between the ends of the splice tails, to minimize the distorting effects that the two splices might have on the rope. And typically the eye circumference is a bit over 2ft., so they can fit onto the machine's pins. I'll look to see if we have saved any results from past tests. The most recent one was on some 5/8" Vectran, as I recall, and it broke in the high 90's, but I'll have to dig the file out for specifics.
As for the whipping vs, stitching question, experience in the field and on the testing machine confirms that stitching works just fine. You ask how invisible stitching could hold well. Reasonable question. Because the rope has opposing diagonal weaves, there's always a layer under the surface. So if I stitch such that the thread disappears between two sets of surface yarns, it will always pick up the layer beneath, as long as the stitch has any length to it. 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. As for inspectability, again, why would you need to inspect it, any more than you would need to inspect the "invisible" buried rope tails?
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; there's more mass in the knot, plus you have the two parts of the eye, so that's twice as strong as the rope. Unfortunately, the bowline, and to some extent even splices, distort the rope, weakening it. The goal is not to have a strong splice --- that's easy --- but to avoid having a weak rope. Hence tapers, core/cover balance, and a general effort to minimize distortions.
I recently spoke with the developer of the Grizzly stitch splice. It's a wonderful thing, but as even the developer pointed out to me, it does have some significant limitations, including the size and type of rope you can use it on. No magic bullet here.
I do my best to have viable reasons for doing things the way I do, though of course it is always so easy to fall into dogma. 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.
Fair leads,
Brion Toss

Thanks Brion - that's encouraging
 

One more question if I may, that has puzzled me for some time. I notice that some ropes are described as spliceable on one end. How is it that a rope can only be spliced on one end, and I guess one shouldn't buy such rope by the foot or something?????

Thanks,
Ron

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. :eek:

love
nick

Well, we seemed to have tangled ropes here - LOL!
 

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?

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.

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.

Re: Spliceable (eye, 1 end)
 

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?

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

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.

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.

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.
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 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!!)

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)]

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.