The "Arborist Splice" in ArborMaster rope - a concern...

I made my first eye splice in ArborMaster 1/2” rope. ArborMaster is a braided cover with a core of twisted strands. I watched Brion Toss’s video where he spliced an eye in New England’s Safety Blue rope. Safety Blue is 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. That’s what concerns me. If the overlap is too much, the rope will have a bulge at the overlap. If the overlap isn’t quite enough, there would be a “shallow”. In the latter case, (and maybe in any case) it seems to me that the strength of the rope at the overlap is really just the strength of the cover, which doesn’t seem like it would be any where near 90% of the strength of the rope as we are told splices can be.

It would take some careful measurement and skillful work to get the perfect overlap. Mine doesn’t bulge or decrease at the overlap, but if that means the overlap is perfect, then it was by pure luck. So, assuming a somewhat less than perfect overlap, say a slightly “short”, the strength of the rope at the overlap has the strength of the cover plus the few cover and core strands inside the cover that actually overlap, some how that just doesn’t seem right.

Thoughts?????

Well, the security of this splice comes from the tight area just at the base of the eye (the throat). That crossover area is merely the transition from tapered tail to the original core. You'll note that in the crossover are of the splice, the cover and core are not connected in any way, they are just laying next to eachother.

16 strand arborist rope derives almost all of it's strength in the COVER, with the core there mostly to provide shape to the rope.

Can we see pics of your splice?

love
nick

Nick,

Thanks for your response. If it is true that most of the strength is in the cover, then the concern goes away.

I'm not the least bit worried about the splice itself.

Pics in a minute.

Ron

Pics (3) at:
http://www.flickr.com/photos/65918986@N00/293043532/

Ron, I did not see in your pictures the final Whipping and stitching of the splice. I think that is a critical step of the splicing process. You can use the "invisible stitching" that Nick uses or the more common one used by Sherrills and other companies. You did a good job thou.

Verrrry observant, Oldtimer! I just finished the stitching. I used white nylon thread and I wouldn't say it's invisible, but it doesn't really jump out at you unless you're looking for it.

I did not whip it. Brion Toss stops at stitching in his splicing videos, but now that you've mentioned it, I think I'm gonna whip it too. I think it looks good.

I'll have to get a bit heavier cord or I may be able to use some of the core 'pull-outs' if they are long enough.

Oldtimer was very right...at a minimum, stitching MUST be done. Ron, you saw what it took to put that splice together, and you know that nothing is really locked into place...it's just pressure that holds it there, so, as you've already done, there's gotta be SOMETHING to hold it together when you're not actually hanging in it.

Good looking splice.

As a side note, you might consider ditching the thimble and going with a much smaller eye. Many people seem to be liking this for climbing, AND it will fit through a RING/ring friction saver, or the leather tube sleeves, too.

Keep it up! We wanna see more!

love
nick

I have stitched the splice, as is SOP for all my splices, I just hadn't done it at the time the pic was taken.

According to most sources I've seen, including Brion Toss, On Rope 1, and a few others, the stitching is really only to keep the splice from being inadvertantly pulled apart under no load conditions or during initial loading. It seems the stitching does very little if anything to actually strengthen the splice.

As for the thimble, this was a special application. The length of rope will only be about 15 feet long and is for cinching around pine trees I do limbless climbs on. I don't know that they are necessary, but I hadn't used one and thought I would.

You are so right about the non-thimbled eyes going through a leather friction saver. I don't know about the 1/2" ropes, but my Velocity eye splices slide right through. My Velocity splices are posted at the same sight as referenced above.

I know how to whip the splices, but I don't know where the whipping should go and how long they should be. SUGGESTIONS WOULD BE APPRECIATED!

Ron

Edit:
Nick,
I thought I'd like the look of the thimble, but it doesn't look like I thought it would; now I'm debating removing it. I guess I should at least try it first.

As a rule of thumb, the whipping should be double the diameter of the rope. About and inch long on half-inch rope.

Stitching is crucial. The only splices I've seen fail (none of which were mine!) were ones that were NOT stitched or whipped in any way.

Well, for what it's for, I can see why you want the thimble in there. I am assuming the tail end of the rope is getting fed through the thimbled eye to allow you to choke the sling onto the trunk of the tree.

The whipping should go on about 3 pics (chevrons) below the eye...but in 16 strand rope, the splice it typically too tight to allow for that, so you just put it as close to the eye as you can.

love
nick

Nick,

Roger on the stitching being critical. Although I do want to be sure we're on the same page about this.

I (and according to Brion Toss and others) am saying that the stitching adds little if any strength to the splice. I tested one of my early splices in Velocity with no stitches and no whipping at 600 pounds, over three times my body weight, and it didn't budge. I did some 600# plus shock loads and it didn't budge.

The stitching and whipping is, as it's been explained to me, is for nothing more than to keep the splice in tact under no load/light load conditions where splice slippage can occur.

As for failures in unstitched splices, I can see how that could easily occur, but I don't think the stitches add the strength to prevent a failure, the stitches add stablity to the splice and simply prevent it from working "loose" and eventually failing.

I wouldn't depend on a splice for anything, life support especially, but really not anything unless it's been stitched.

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?

love
nick

Nick, what about the G-splices (technically a sewn eye termination) that Petzl, Beal, and some major rescue rope makers use?? its simply the rope end folded over and sewn, with standard thin thread.....and then covered witha heat shrink sheath to protect the sticthing. What are you views on this? Petzl and other claim a sewn eye termiantion is stronger than a splice.

i was shown how to do this sewn eye termination by a marine splicer locally (cost me to do so, but ) and it is very easy to do....I used 100lb test polyester sailmakers cord for thread, on a piece of arborplex. Came out damn tough, i tested it with a 4 ton comealong and very slow pulling, to mimic climbing condtions...still has'nt come apart or moved. Its low profile, and i liek that fact that i cna finally have an eye temrination on my Arborplex

this is the gsplice that petzl has:
http://en.petzl.com/petzl/ProFamille?Famille=31

you can see the G-splice (sewn eye termination) on the left.