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Using steel figure-8's in-line on a rigging line to slow/control its speed?

eye.heart.trees

eye.heart.trees

arborjunky
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I haven't seen this but can't get it out of my head, am picturing using figure-8's along a rigging-line to create friction before the highest anchor-point, literally just string the rope through the 8's (1, 2 or more of them, each lashed to the trunk with a length of rope) in a manner where they're going 'in through the back / out through the front' meaning the weight/force as it hits the trunking would be on the dead-center back-side of the figure-8 (can upload a picture if useful), you could put 2 or 3 figure-8's in-line when setting-up your rigging line so that, when you make the cut, the piece's ability to descend your line is forced through a figure 8 (or 3 of them at spots on the trunk, you could even be directing the line a bit this way, and can't imagine you'd need more than 8-10mm rope for lashing the 8's to the trunking so they stay put at the heights you'd set)

Do people do this? If not, why? The biggest worry I have is that adding so much friction to the rope could be bad for the rope, but at the same time I could just spread that load by using extra figure-8's in the system, am picturing using 3 or even 5 figure-8's on the standing leg of the rig-line so that when you cut the top or chunk something large the piece's descent is inherently pulled-through the figure-8's, you'd set a # of figure-8's based on how much friction you wanted to induce of course!

Thanks for any advice on this, am guessing it's obvious I've never done much rigging before, am asking this in the spirit of purchasing because I was looking at the portawrap for base and a block for top anchor but then started thinking "why not just use [2] Figure-8's instead of a block?" as it'd slow descent which seems appealing (at first / when new) and then realized I couldn't think of any reason that 8's wouldn't suffice for the entirety of friction-control here!
 
Haironyourchest

Haironyourchest

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So you want to create friction up high, rather than down low with a portawrap? Will you be lowering the pieces yourself, from your position in the tree, rather than rely on a groundsman? If so, there is a device for this, I think it's called the Safeblock, it's a block of aluminium with three highly bevelled holes in it.
 

Yarz

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'in through the back / out through the front'
This statement as well as this one

picturing using 3 or even 5 figure-8's on the standing leg of the rig-line
Make me think that you are talking about stringing them up the trunk, like a fishing pole. Is that what you had in mind? If so, that's possible, but may not add the friction you are looking for. Plus, with the Portawrap at the base, you shouldn't have to add additional friction, unless you want the friction in the canopy.

If you are in fact thinking about adding one in the canopy as a rigging point to change the forces on the tree, then yes, it should work, but as Haironyourchest stated the SafeBloc is probably a better option. I'm not 100% sure, but I think I remember reading that Figure 8's can impart a twist in the line, which would be undesirable for rigging.
 
eye.heart.trees

eye.heart.trees

arborjunky
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@Yarz I believe the kinking ('hockling') is due to using it for descent, I've yet to have much issue although I seem to change ropes relatively often but the way I was envisioning them shouldn't encounter this as the rope would go 'straight through' (from bottom through small hole in the 8, then down&out the large hole or vice versa as I imagine you'd want the large hole as the side that gets tethered to the tree, as you say like a fishing-pole)

I have and love my Safebloc I had it in a 3/4 p.dyne 20' tail and recently moved it to 3/4 TEC 9' whoopie it's my favorite terminal anchor, also have 3 more ringed anchors that're all more-or-less suitable for terminal anchoring or heavy-duty redirecting, with 5/8 bull rope it works a treat it's amazing how little you have to rely on a groundsman to do anything but relieve some pressure (timing/running hasn't been of much relevance on medium stuff, I haven't done anything past medium using a single anchor though...even when it's in 1:10 it makes me nervous thankfully it doesn't happen often but if I expect a peak forces to get much over 1k a single anchor makes me uncomfortable am lucky I've had little 'rush work' where it was heavy wood and am limbing more often than felling)

@Ketchup I don't think it would....are you picturing the bull rope running in-parallel, 100.0% over the whole way, with the fig.8? I don't mean to run the rope as-if you were setting up for human descent (which will hockle rope over enough time) my idea was to tether a large fig.8 to a tree with say 1/2" or 5/8" sling and run the bull-rope through one hole/out the other, it'd be a floating anchor/re-direct used for adding a lil friction and for spreading forces (fish-pole'ing, spreading forces *through* a canopy, moving them away from a weak point etc etc) Have to imagine the minimal friction of just passing-through one hole/out the other would be ~comparable to a Rigwrench and they're 'mid-line-leavable', feel like they'd be useful but sadly I've since become of the mindset that 1/2 isn't a suitable bull-rope for default in fact I only use 1/2 when I need its length (have much longer 1/2 polydyne than 5/8) so unless I wanna spend like $50 per fig-8 for oversized gear I couldn't fit it properly (although maybe having some that're quickly tethered w/ my 1" nylon loops in my gear bag for rigging-with-1/2 would be useful!), nevermind that w/ a Safebloc, a 3-ring sling, a giant-ring sling, 3/4 steel thimble sling, am now able to use those to effectively spread more forces than I'm currently comfortable cutting lol, LOVE the 5/8 polydyne with rings it's such a winning combination lol seriously it is amazing what I can cut with just 1 guy on the ground and I mean sometimes I've had to have things slowed super fast ie a shed is <10' from the limb so I just set more anchors lol and use all 3 holes in the Bloc (want a 2nd so bad, can't stomach paying MSRP for a loose Bloc and can't find anything better right now, it's a shame how under-used that thing is due to over-pricing IMO I mean it's such useful rigging hardware I see it as 'optimal' for 99% of rigging cases to use it as the terminal anchor, beefed-up / added-to when needed (heck LawrenceSchultz3000 on youtube has some *amazing* footage where he's double-whipping stuff using like 3 Safeblocs and Porty's in these insane setups that honesly are likely far safer than the average Tree Co - maybe I've had bad luck in my beginnings as a contract worker but finding a lot of disreputable folk...

Will put my extra 8's and all my 1" loops into a bag tied to my 1/2 bull rope so I can try this -- I don't see how using just one could be far off from using a 'Rig'n'Wrench', friction is WRT surface-area so if you can get fig.8's for $10, and 1" nylon runner loops (which are mid-20kN's strong) for next to nothing, you could realistically have 1 or 2 of these loop+fig.8 combo's to be comparable to a RigWrench **but** for the bargain of like $50 you could get like 5 of these loop+fig.8 pieces so you can pull your bull-rope around wherever you want and have it terminate up top with 1-2 proper terrminal-anchors (not that you'd use a RigWrench as terminal anyway, well nowhere you wouldn't also use other ill-conceived ideas like that loopie-omni-block thing some are so in-love with..)

Can't imagine going back from 5/8, it's affected hardware choices for instance #2/Lrg rings won't take a spliced 5/8 polydyne so yeah....when my 3-ring X-sling finally wears-out I'll be using #3's/XL's only (and Safebloc(s)), with the friction they provide on 5/8 it's blown my mind how little I've had to worry about groundsman-competence, that's not to underplay safety by any means am just being honest I mean it's way too frequent that something we've got something w/ too much friction (ie it's hardly moving after being cut) than too-little for 1-2 guys on the rope to handle and I can't overstate how green some of the guys I've had on-rope were...I've also been on the ground while others cut w/ my gear and have handled 1/2 and 5/8 polydyne and 11mm Mercury (same elasticity as p.dyne, ~85% as strong per-diameter) and the 5/8 isn't just (way!) nicer in the hands it is softening the blow so much it is clear beyond doubt, I've compared Mercury to 1/2 p.dyne (relatively comparable dynamic-strengths) and it made the 'hand feel' aspect clear, and that is apparent between 1/2 and 5/8 p.dynes, but their thicker diameter is 'biting' the rings/Bloc(s) so much harder that it doesn't matter if the largest cut will just be some 420lbs log, and we're using 1 anchor and 1 groundsman (ie from him to me at the anchor to the log, no basal setup in fact that's a "only on heavy stuff" thing for me), it's hard to see others using tight 1.2% bull rope on tthese slick 4" wheel blocks when it's just creating this 'game' w/ the groundsman where their ability (and reliability) to run something properly is critical....w/ my 5/8 + rings setups I could literally have 1st-day'ers for most of my jobs and it wouldn't matter, it's just "don't let it come to a COMPLETE stop any earlier than [xyz]" so I'm not being shaken if they snub too hard which is often very very easy w/ my setups although thankfully the rings +/- rope seem to take-up a good deal of that shock for instance I've had limbs of like ~250lbs snubbed on me when I was on relatively-thin diameter limbing myself and have damn near had a heart attack, now so long as I setup 2 slings for any job and add 1+ as weights go up, anytime something's been snubbed it's been no big deal I've never been shook like I had in the past when using a single anchor point (a low-friction one, w/ 1/2" bull rope)
 
Ketchup

Ketchup

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I may have misunderstood how you want to use the 8. You want to use it threaded like a Safeblok? How does it attach to the tree?

Honestly, I’m not sure what you’re wanting to do. A picture would save a lot of explaining.

I’m all for new ideas. Just be safe.
 

Yarz

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I also misunderstood.
I was originally thinking you were going to thread them like for descent, or using this fishing pole technique:
. But instead of the clevis shackles, you were going to use the figure 8's.
Now I read it just like Ketchup, where you'd like to thread it like a SafeBloc. That should add some more friction.
 
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