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Q's on various splices (how to make 'foot-stirrups' w/ hollow-braid, whether I can use prussiks to 'catch' spliced hardware on a sling for adjustability, and what to look for when splicing 12S hollows as eye2eye split-tails :)


ArborOdyssey
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I'd gotten a bunch of 3/4 polydyne for all my slings because, hey, it's the strongest dynamic-strength/shock-absorbing bull-rrope out there!!  Problem was I never used my favorite hardware (Safebloc) because it was in a "difficult" 20' tailed setup that required knotting.....sounds lame but 9/10X I'd almost be 'rushed into' just using my 5', 3-ringed x-sling because it's so easy tto set and move-down a limb re-setting it..   Ssssoo, I got 3/4 TEC and made a ~9' whoopie for my Bloc, hopefully will use it as a go-to now (can make it any length, really, as I'll be splicing a long loop from the 3/4 polydyne sling I'd taken it from!)  Have another ~15' length of it, and a loose Elevattion Canada #3 ring (10% wider than x-rings but otherwise tthe same, just cheaper I paid $47 (shipped) for mine but they've got 2-packs on ebay for $75 am close to getting more I just don't need  more hardware :P ) so that'll be my last DB sling, holding a single XL/#3 ring.

 

En route now are two lengths of Samson hollow-braid, am hoping for any advice possible here as I'm good w/ double-braids (can do blue moon all day) but besides my whoopie I've done nothing w/ hollows, what's coming is:

 

 - a length of Ice Tail to make 1-->2 prussiks (got 12' I think, maybe 10' of it?), am climbing on the amazing Mercury line and Ice Tail seems an ideal complement to it, not only do I want to uses spliced eye&eye hollows for all hitches going forth but the 8mm Ice Tail, still 8.5k lbs strong, is as-if it were made to be a hitch on Mercury....my problem is that in the past when making some ~3.5' b.moon lanyards (simple lanyards w/ a 1/2" thimble in each eye) I found I was having some trouble, seems there's a minimum-lengh to have in-mind here and I just dunno it!!

 

- a length of 5/8 TEC, getting another so I can do both but 1 will be for a foot-loops/stirrups slingn and the other will be either splicing a 5/8 thimble to each end, or making a loop, am uncertain which is a stronger setup am guessing the former but can't be sure but just want strength so I can use it as-prussik to 'spider leg balance' off my bull rope (5/8 polydyne)  **ALSO** am very very curious what the #'s are on prussiks, can't get it outta my head:  since a prussik has 2 legs it's 2XABS, so w/ an Ice Tail as prussik it'd be ~17k lbs strong, am asking because I'm seeing my loops here as a way to use, say, a long-tailed double-braid sling that's got hardware on one side and a prussik or two on the other, so far as I can picture it'd simply act 'as a catch' for the hardware, for instance I could have a Safebloc spliced-into one end of some long sling but, when it's time to use, you throw the Bloc/hardware around the spar and adjust the prussik(s) so they 'catch' the Bloc (like the adjusttable eye on your whoopie would), don't get me wrong I'm in love w/ TEC now but still wanna find out for sure  yknow? :D   Re making an adjustable ffoot-stirrup unit, is it fair for me to presume it'll be effective/versatile enough that I can ditch myspurs from any 'work positioning'?

 

Thanks a ton for any help on any of his

 

Ideally I'd like to order some 7/8 TEC (just for peace-of-mind I know it's over-kill) and make a whoopie using a single '#3' Elevation Canada ring I've got (it's ~10% wider than an XL x-ring), but having seen 'not for climbing' on some rigging-ring products has me hesitating to order the cordage :/  Hmm maybe I'll order the 7/8" tec anyway and use the setup as a redirect or alongside my Safebloc as a terminal rigging anchor if climbing-anchoring isn't OK!

 

Would also be curious whether anybody could tell me *anything* about how prussiks perform in rigging-sling applications?  Specifically, I'm looking at a 3/4 polydyne sling (long 15' tail with a generic 3/4" steel thimble in its eye) of mine and wondering why I couldn't just take a couple loops of climb-line (mercury & blue moon on-hand), make prusik(s) to put on the other-side of the line and then 'choke' hm up, I can't fault this idea yet since I've never seen it it makes me wonder..)

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I should ask as well: these types of 'whoopie foot-stirrup slings', are they suitable for stance while cutting, ie could I be strapped to my sides and use the stirrup as 'point #2' the same way someone would use their spurs?  Of couse spur are so much more versatile but, while I've yet to even try this configuration, I have a feeling it'll be a game-changer for me so far as comfortable work-positioning as it looks like you can just sling & adjust it, tthen your feet are floating in soft TEC instead or dealing w/ spurs! Hell I'm already thinking 3/4 or 7/8 would make a nicer footttties-sling(lol!) but just wanna make one or two w/ 1/2 or 5/8 first so I can work out any issues!!

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Footloops aren’t that stable to stand in because it is hard to keep your center of gravity over your feet.  Your toes, or the side of your foot need to be touching the tree to prevent your feet from swinging out from under you. I use them to mostly support only one foot at a time.  If you wear hard sole boots smaller cord is always better for weight savings, and there’s no need for a high break strength if it’s not for life support.
 

Splicing 12 strand is much easier than double braid to splice and doesn’t have the length limitations that you mentioned.  Straight bury, lock stitch or plain Brummel, and locked Brummel are three ways to make eyes, it’s a strength vs security issue on which to use.

The Ice Tail splicing instructions from the manufacturer might still be wrong on some of the measurements resulting in a bump in the middle of the hitch cord.

 

I don’t think friction hitches are recommended for adjustable slings that will be shock loaded, they may slip and cause rope damage.  Spider legs are different because mostly static loading only.

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  • 3 weeks later...
On 18/02/2020 at 13:02, Brocky said:

Footloops aren’t that stable to stand in because it is hard to keep your center of gravity over your feet.  Your toes, or the side of your foot need to be touching the tree to prevent your feet from swinging out from under you. I use them to mostly support only one foot at a time.  If you wear hard sole boots smaller cord is always better for weight savings, and there’s no need for a high break strength if it’s not for life support.

Outstanding thank you!!  Do you have any keywords I could google?  Stoked to even find someone who's understanding what I mean by 'foot stirrup sling thingies' lol, Samson's industrial-catalog (actually may be the arborists' catalogue) shows pics of it on the TEC spec-page right alongside whoopies but leaves it un-named....have gotten quite good at splicing hollows and double-braids (only missed my 1st attempt never failed again and Blue Moon was my main cordage when beginning to learn ;D ) so am just dead-set on making SOMETHING I mean a foot-step "branch" where none existed, even a crappy swinging branch, is still of value especially to smaller, agile guys like myself :D  

 

If you could explain the actual cordage configuration I'd be forever grateful, it appears the sling's main cordage is simply a 12-strand spliced in a whoopie-type style but that'd just give 1 foot-stirrup and the pic Samson shows clearly shows 2 feet being supported (but the tree blocks view of the way the sling is configured) so am getting desperate to figure-out how to make my own version of *that* so I've got a baseline to begin playing around from (for instance, *especially* with you saying it's more of a 1-foot thing -- hell this idea would work on a standard whoopie I think -- I'm immediately thinking "Just add a prussik-loop to the sling for the second stirrup, can be placed wherever needed and, since pressure on that loop's hitch would be lateral to the cordage, it'd only bite as hard as you wanted it to IE you could even leave it loose-ish[with practice] to set it by-foot to proper position before reaching-down to fully engage it by-hand"    Pretty sure Samson is using something more intricate than just a whoopie here but in any event am curious to see how prussik-loops may be able to help such slings (Samson's pic from industrial catalogue, would LOVE to know what this is called/named!

19700102_204510.thumb.jpg.97cfaddbb4ea62432f52afcce03b655f.jpg

[I guess they do 'name' it although I've put that name through google, adding 'foot'/'stirrup'/'steps'/etc etc ad infinitum and get nothing of that ^ sort....a skinny agile guy like me is likely to benefit the most from those if they're not really so stable, *gotta* figure out how to build these!!]

 

Even if it was a 1-foot thing I bet it'd be of-use (at least *sometimes*, good to have on-hand!!), am going to try using a generic "eye&eye" ~32" sling I'd made of 5/8" TEC (generic rigging-sling, not anchor but for holding logs for knotless rigging), slap on 2 or 3 Mercury (3.5/8") loops onto it with 'biners so I can bind it and use the Merc loops as the stirrups (two of them, and the 3rd used w/ one of the TEC eyes to cinch the 5/8 TEC body of the sling to the tree....so far as I can see you just need to be choking-off the spar, and to have loops- better builds should be more versatile, not more useful/functional, if I'm understanding the overall approach/usage here...am picturing using these for the times where I think "it'd be nice to have my spurs on but it's not worth it so will deal w/o them" yknow, and it'd only be 1 extra sling brought-up with me as I've always got extra prussiks on my belt :) )

 

Agreed on diameter, have 20' of Ice Tail coming for prussik loops (and a single eye&eye for a doubled-over treesqueezer sling, when doubled-over in a spliced formation Ice Tail becomes 11mm wide) and was thinking to just use that for weight/size but I often climb w/ soft athletic shoes (am in FL) so will have to figure something out, am good at McGuyver'ing hell am already thinking I could simply use the foam handles from those rubber-band stretch/exercise bands as 'wrappers' over the Ice Tail inside a prussik loop so my foot was on that instead of directly on Ice Tail :)

 

Have you ever tried anything like this yourself?  Thanks a TON for replying, so glad to have found someone who understands what I mean by 'rope stirrup thingie' lol, really appreciate the info will update soon enough once I've made my first one or two of them :D

 

 

 

On 18/02/2020 at 13:02, Brocky said:

Splicing 12 strand is much easier than double braid to splice and doesn’t have the length limitations that you mentioned.  Straight bury, lock stitch or plain Brummel, and locked Brummel are three ways to make eyes, it’s a strength vs security issue on which to use.

The Ice Tail splicing instructions from the manufacturer might still be wrong on some of the measurements resulting in a bump in the middle of the hitch cord.

Glad I cut my teeth on Blue Moon, had done that and 3 sizes of Polydyne for my rigging kit before splicing my 1st hollow-braid (9' Safebloc whoopie, came out great think I got it "to the pick") however am embarrassed to say I'm uncertain what a "locked brummel" is, will google right now, had always just followed Samson tutorials to the letter and it's always worked a charm so stick to that, they actually have eye&eye instructions meant just for 3/8" TEC, Ice Tail and some other comparable cordage they sell so I'd used that for my 1st eye&eye and, following instructions on length & thinking I'd be cutting-off like 7" tails from the middle at the last step, turns out they were too-short and instead of a bulge I actually have a spot where there's nothing inside the Ice Tail (ie the two tails aren't overlapping inside there) so am sure that's a serious strength-drop would never use it as a prime life-support although I'm usually climbing w/ 2 prussik loops on my line (lol that'd warrant a video to explain!) so not a biggie for me...their guide said 80" makes a 33" eye&eye, I'd wanted 31.5" so I used 77" of Ice Tail (80" minus 1.5"X2) but instead of 31.5" got 29.75", will be taking measurements tomorrow when making more to get an idea where I messed-up! 

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Am hoping to get Richard Mumford to do some break-tests for me in the near future to test out some of my creations actually, although I'm probably going to use a boulder/limb and 'rough testing' in my yard to generate the dynamic-forces to test:

On 18/02/2020 at 13:02, Brocky said:

I don’t think friction hitches are recommended for adjustable slings that will be shock loaded, they may slip and cause rope damage.  Spider legs are different because mostly static loading only.

Do you know where "proper" breakage/failure should occur in such situations?  IE in a proper setup that was intentionally pushed to fail, should the failure be the prussik tearing, the host-rope tearing, or the prussik slipping?  That last one seems the least-likely to me although I've had someone suggest it, seems impossible in my eyes I mean once a prussik begins biting more force just = more bite, can't see how that'd do anything except cause failure/breakage when increased, not slippage!! 

I totally get that the config isn't meant for shock-loading, *but* (IMO) neither is Stable Braid or Tenex and, by virtue of being such strong damn cordage, its lack of dynamic-capacity is negated by sheer tensile strength, so am thinking that if you just kept to a strict 10:1 *MAX, EVER!* safety-margin then having a 5/8" TEC prussik loop on a 3/4 TEC line that's got a ring/safebloc on its other end should let you get away with some serious loading, gonna have to test this as this is 3rd forum I couldn't find any real datas on prussiks/fric.hitches (hell I still can't find an answer about how strong my Ice Tail is when used as friction-hitch, I mean it's 2 legs so is it 8.5k lbs times 2?  But it's a knot, of sorts, so there's that reduction....wish Mumford got sponsored to do far more testing IMO he's a god-send for this type of stuff!!

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The Samson Endless Loop Sling looks to be just a spliced end to end loop, girth hitched to the tree.  The other foot might be in a separate sling.  A fixed length limits what size branch you can use.  Various lengths would be needed, or an adjustable Loopie, which you might to be able to make a double foot sling.  Ready made slings can be much smaller and store easier.  Coverings for the foot loops can be what best suits your wishes from just protection to stiffness, if not using hard sole footwear.  The loops aren’t useless, I carry a few in different lengths of the dyneema ones in small pouches.

 

Locked Brummel is what you did on the Icetail splice when the short tail went through the side of the long part of the rope, and then the long section passed through the short tail. The thin spot on the Icetail splice is completely safe to use with the break strength of just the cord itself being considered.

 

I remember reading that a Prusik will slip at around 1000lbs.  Some other friction hitches will strip the cover before sliding.

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  • 1 month later...
On 09/03/2020 at 10:24, Brocky said:

The Samson Endless Loop Sling looks to be just a spliced end to end loop, girth hitched to the tree.  The other foot might be in a separate sling.  A fixed length limits what size branch you can use.  Various lengths would be needed, or an adjustable Loopie, which you might to be able to make a double foot sling.  Ready made slings can be much smaller and store easier.  Coverings for the foot loops can be what best suits your wishes from just protection to stiffness, if not using hard sole footwear.  The loops aren’t useless, I carry a few in different lengths of the dyneema ones in small pouches.

Brocky :D (I'm eye.heart.trees from Buzz if it's not obvious :P )

 

I use soft-sole almost exclusively...

 

I think I solved it (Samson's advert certainly seems to be advertising it as a 1-piece, 2-foot lanyard and that's what I'm set on!), it's not 'a hard problem' just a question of how simple/sleek a configuration is needed to solve it.. Anyways I'd very very much appreciate yours & others' thoughts on my solution before I go and make it:

1 - 3/4TEC whoopie as main lanyard-body.  Adjustable-eye set to choke whoopie on the stem with a ~10" 'eye protrusion' of the whoopie's spliced-eye dropping-through the adjustable-eye.  This is 1 foot stirrup.

2 - a 1/2TEC prussik loop is on the body of this ^lanyard, the loop is long enough that, after 3 wraps on the 3/4 body, it's ~10" long.... You slide this on the main 3/4TEC body to where you want your 2nd foot-stirrup.

 

^That should do it so far as I can see: 1-piece, simple/quick setup, secure/cinching/choking type setup....something tells me @Samson's perfect version is a funky whoopie splice wherein the adjustable-eye's "extra rope" is fed back-into the sling, can't imagine it's got 2 means of adjustment would be too risky/would be safer/simpler to just have a whoopie's fixed-eye be the fixed-stirrup, with adjustments made to length & 2nd-stirrup-placement.

 

Pretty psyched if that solves it, can't really fault the idea but only came up with it while reading/working-off-of your post so may be missing something....seems bulletproof & simple, will be nice if it's really this easy :D

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