Using Ultrasling anchors for *negative* rigging?

[ArborOdyssey]

On 22/11/2020 at 13:22, Paddy1000111 said:

Here's one of the rings I spliced in, so tight it's hard to rotate and locked in by lockstitches. I have quite a short end and I whip the tail just so it looks nicer

Beautiful!!  What are you using to do that label&heat-shrink?  Could you explain a lil more how you did the 'butt' on that?  I can see the bury  looks to be ~6" (and tapered, if my eyes don't deceive? Looks like it thins starting midway on the left-sticker), am guessing it was basically "Bury, then bunch-up & lock the remainder"?  That's basically how I did mine, maybe a 6" splice if that and, with the lil extra few inches, I had to fight it to do a 180 to "backsplice", didn't truly bring it "through" the rope it was too short (by design) but just long enough for me to flip it back into the 'butt' and lock-stitch it in place.  I'm gonna have to google because I don't even understand why you'd need a real splice at the end, if the brummel-pocketing is suitable then, after the last brummel, it shouldn't be an issue of strengthening things it should simply be "wrapping up the loose ends"  (IE part of me wanted to just do 4 brummels at the end and only leave enough tail for me to lock-stitch into a lil 'ball' directly after the 4th brummel, will definitely be doing so the next time I make an Ultra!)

 

What rope do you run through that? I wish the #2's were just a hair bigger because you cannot get spliced 5/8 through them, and 5/8 responds (friction-wise) very very well to the Lrg rings (actually you can fight the splice through but I mean *fight* it, will take you well over 10sec to work it through, not something you'd wanna mess with while climbing & actually using the thing!)  So my Ultra (having just the Lrg's) is only useful for my 1/2 bullrope, until I remove/destroy the splice on my 5/8 at least!

[ArborOdyssey]

BTW I love how high-up you got that 1st lock-stitch!!

 

Re tightness, I have to imagine you mean 'wouldn't rotate when-new' right?  IE that, from usage, it must rotate freely by now?  I was using pre-used TEC so think I would've been a bit afraid of genuinely making it "tight", I mean I made it as tight as I could by hand but so far as using tension on the line first .....man my curiosity is piqued, can't help wonder if I'd have made it tighter or not.....I think I've seen tight eyes as less-than-optimal because you've already removed some of the cord's flex(ie shock-absorption), thankfully these (cordage & hardware) are all so bomb-proof that lil strength losses are pretty meaningless!  But I imagine that, with tension on the line, I could've set my 1st brummel about 2  crowns lower, and - in the sling's relaxed position - the TEC around the Safebloc would be tight/under-load at all times, I know that that is (of course) tighter on the eye but makes me wonder about strength / cycles-til-failure if a rope is kept taut....but yeah I doubt that matters as much as further-securing the hardware, will definitely be putting the line under load as you instructed the next time I make a sling!

[Paddy1000111]

In regards to putting weight on the line I usually do the first brummel tuck, tie one end on a rafter and pull down the other end either with my foot in a loop or with a weight so it cinches on the eye and then I put a marlin spike or a couple of large needles through the first brummel just to pin it in position before doing the next two. The cinching force is removed when the needle is taken out but it just helps hold everything in place so the brummel is tight to the ring. 

 

The label and heat shrink is just a Brother label printer (PTE550) with wide tape. The other bit is just clear heat shrink that's adhesive lined. one piece put on, labels attached and then another piece that's 1" shorter put over the top. Same stuff they use for the labels at honey brothers. The butt is basically 3 inches of the rope back fed into itself so it gives a clean end. the other 5 inches or so is just regular buried end. Both the back fed end and burried end are just flush cut with no taper and they both meet under the heat shrink so there's no soft spot in the tail as it's under the heat shrink. Before I put the heat shrink sleeves on I lock stitch it to stop either end pulling out and then I put on the whipping. The whipping is nothing special, just a standard whip that you would usually do on 3 strand. Wrap it around a load of times so it's tight and then sew the end over multiple times to give that drillbit/corkscrew effect. 

 

AFAIK the burried section isn't really giving any true support. If all your brummels have given out then the ropes snapped anyway. 2 ft of burried tail isn't going to save you. 

 

I run 14-16 rope through it. No need to run any bigger. I do most things with 14 as unless you're chunking down massive sections I just take smaller cuts. The 15.9mm T-rex is rated to 5900 Dan when spliced so roughly 6000kg. Rigging safety factor is usually 11x so 545kg force. My 14mm sirius bullrope is 5302kg so 482kg by the time you safety factor it. Now when you have a rigging rope going through an eye the force on the eye is double the weight of what's on one end of the rope as you have say 100kg of wood on one end and then 100kg of groundie on the other supporting it so the weak link now is the T-rex which can only now handle 272kg of wood. No groundie on earth is going to be able to support 272kg of wood so you need a basal anchor of some sort. I use a flying capstan usually. The flying capstan has a safe working load limit of 10kn which is 100kg by the time you safety factor in for the negative rigging. So Really, the biggest piece I could safely chunk down in negative rigging without fear of going over the safe working load limits of my gear is 100kg. Why have a rope larger than 14mm? 

 

I know what you mean about removing some of the stretch but we are only weak and frail humans. Us pulling the line tight with 10-20kg of force isn't going to remove any real amount of the dynamic absorption of the rope. If it did, it's no good for rigging ?. The force we are talking about being on the rope in the relaxed position with all pins/tape or whatever removed is under a kg. In my mind having everything appropriately tight stops chafing of the splices as things move about on/off load