3:1 DWT with RnW and OmniBlock Pulleys
JeffGu

3:1 DWT with RnW and OmniBlock Pulleys

The RnW would actually be close to the climber, and further away from the pulleys, but scale is an issue trying to draw things with Paint.
Yes... and it looks a bit more refined with a vector drawing program than my .bmp doodling with a shaky, wireless mouse that's on its last leg.
But the shaky mouse creates the best bark texture.

A *very* sophisticated schematic-capture program - nay, more of a 'software suite', really - was used to create that last diagram: MS Paint xD
 
you may need 2 or 3:1 ma to lift a limb, but not to lower it
You certainly don't "need" mech advantage to lower thing (and don't think @JeffGu was implying anything of the sort), rather mechanical advantage when downward rigging is for more control for instance the most common example/use-case I can think of is a whipping or 'double whip'/double-block-whipping where instead of the bull rope terminating at the log-to-be-cut, it goes *through* an anchor on that log (like an XL rigging ring for instance) and back to the stem nearby its anchor and is tied to the stem, when the piece falls it's now 2:1 (I think) as it's pulling 2X the rope as the falling-log's ring pulls 20' of rope to the ground when a log is only taking a 10' drop. "Need" is almost a loaded term / not objective enough for my liking but, needed or not, to reduce the groundsman's required-strength by 50% is a huge deal and his setup here is doing more than that!

@JeffGu - I like the overall concept but think I'm missing something because my 1st thought is simply "Why not ditch all that and instead use a Safebloc where the RigWrench is and, on the log-to-be-cut, set a 2nd Safebloc to double-whip w/ 2 safeblocks" am not sure how to do the math but imagine the friction & mech-advantage would be comparable, the setup would be easier (as everything that needs configuration is in one spot not spread like your picture), and it'd be lower pressure on the tie-in-point for the terminal anchor since it's a Safebloc with friction *after* the anchorage-peak (whereas I'm quite sure RigWrench *increases* peak force at the anchoring location as the friction is *before* the rope goes over the branch so just like friction from lower on a Porta it's still pre-"over the limb" tension....gotta say I'm curious how much difference in peak-force any of this stuff makes, for instance does a Safebloc reduce my peak-force relative to a pair of XL's by 60%, or 6%, yknow? If closer to 60% then, IMO, a closer look needs to be taken because (IMO) that'd mean the Safebloc was the smartest terminal-anchorage-hardware for anyone to default to (it's certainly how I setup, Safebloc whoopie as terminal and as many extra rig-ring-slings as needed based on bull-rope's needs, based on tree's structural integrity etc etc)
 
Also.....will say it despite how embarrassing it is......no matter how many times I look at your sketch @JeffGu , that pulley/block that's right-beside (right to the left) of the RigWrench, no matter how I look at it I see that as a useless/do-nothing piece of hardware in there, could you 'baby-talk' it to me so I can understand it? I'm looking at it thinking "everything the pulley could do in this config is already done by the RigWrench", it'd be one thing if there were something in-between them but there's not the rope leaves the rig-wrench and, before going to the pass-through loop on the log, it passes-through a pulley and for the life of me I can't think of any reason that pulley would be of use (unless it's merely load-spreading?)

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*May* be stupid but think I just had a GREAT way to make your concept here an easy practical-approach... If I'm understanding it correctly then that first pulley is superfluous (the one beside the RigWrench) and the config is essentially a double-whip only instead of the rope going-through the log's hardware and then tethering to the tree, it goes through some hardware on the stem and travels back to get tethered to the log itself, SO.......instead of your setup, why not just call it "the JeffGu triple-whip" and, where one would normally tie-off the bull-rope's end for a double-whip, this method would have a rigging-ring anchor in that spot so the rope could go-through that and back to the log & get tied to the log!!! All the rope trickery / force-reduction but so clean and able to setup from 1 position on the tree :D Would be happy to illustrate if that wasn't clear as I'm stoked on the idea now and eager to try it, the regular double-whip is something I see less as a "when needed" technique and more a "good practice" technique (like I do *anything* that reduces peak-forces, or increases safety%, etc etc) so trying to make it my default whenever able, F'ing LOVE that you made me realize the obvious IE that I can just as easily add another hardware sling to the stem right-beneath the main/terminal anchorage and run the bull rope through that - right where it would've normally been knotted to the trunk -- and run it to the log/knot it there instead, this should be nearly as simple to setup as a double-whip it's just a couple extra steps (same steps tho!) and adds so much more cush, dude thanks a ton for sharing I need to review your albums I always get cool ideas from you (hopefully I can return the favor a little, have made a lot of stuff lately am about to start posting some of it this wkend :D Favorite new toy, besides saws lol, is my set of treesqueezers (like Buckingham's but better), so confused how the concept/configuration hasn't been in-use for ages now as a default instead of the regular flipline-lanyard, feels so damn nice tethering myself to a fixed, o-ring'd anchor point instead of just flip-lining up nevermind how a doubled-over rope of most types will beat a single-length rope which means using a treesqueezer as a false crotch is better than most-any of the magazine's $100 adjustable lanyards or false-crotches (am using 8.5k lbs ABS Mercury for mine, it's a 7/16" like Buckingham's "Uniline" on their TreeSqueeze, and while I can't find *any* specs (ABS, elasticity, even fiber-type or construction-type!!) online for Uniline, which is beyond disturbing IMO, what I do know is my Mercury, when doubled-over, can be as strong as 17k lbs and has 3.5% stretch so as far as any false-crotches I've ever made I can say w/o doubt I trust this type the most and by a pretty wide margin hell on my main/long treesqueezer the weak-points will be the *pairs* of o-rings at connection points (I like idea of multiple connectors, 95% for bend radius and 5% for the redundancy of it, however as said I couldn't even approach the cordage's ABS with a single ring I needed 2 o-rings in all spots just to get me ~mostly-to the cordage's ABS(when doubled-over/in basket config) Will try and link-back the pics as I'm about to make a thread on the topic, I wouldn't advise buying a Treesqueeze but am now ready to advocate that the average climber would benefit from a DIY treesqueezer, and that it should be seen as a tech/configuration not a product!!
 
The RnW wouldn't be right there... the drawing isn't to scale. It would be close to the climber, when I do this, because I use the RnW as a redirect and keep it close to me. The RnW isn't part of the MA and is just used as a friction brake. You could put any other such device in the chain, as well... AFB, PoW, etc.
 
The RnW wouldn't be right there... the drawing isn't to scale. It would be close to the climber, when I do this, because I use the RnW as a redirect and keep it close to me. The RnW isn't part of the MA and is just used as a friction brake. You could put any other such device in the chain, as well... AFB, PoW, etc.
Why use a pulley right-after the RWrnch, is it just to bolster strength there ie the RigWr isn't that high a WLL so the pulley fixes that? Also, even though I know the branch-end isn't to scale / is suitable for that pulley, IF it weren't as solid as you'd like would using a Safebloc there still cause the lessened-loading at that point? I suck at picturing force-vectors once mech.advantage is involved..

IIRC, you mostly rig solo (I do), I love these types of configurations because I'm either rigging solo or with groundies I either don't know or have only worked with a few times so I aim for systems that allow the greatest degree of control from-canopy, also for systems that just inherently dampen/reduce the actual peak-weight of any given piece once it's cut IE heavy in-system brakes (friction-hardware), am already looking at your config and wondering how much weight I could move that way, solo, if using Safeblocs at all 3 positions and, before-system, having a lil Porty in the canopy right-after my hand-position on the rope....if I had the means I'd go and test it right now, someone's gotta come up w/ an Enforcer lease-program ROFL!!
 
Yeah, normally the pulleys are high up above me, and the RnW is very close to me... I use it as a redirect-with-friction. Also, the pulley shown out near the end of the branch isn't really that far out, or is on an entirely different branch. I just did a removal between a fence and a house where I removed all the lower branches of the tree this way. The outer pulley was actually attached to a branch in another tree in the front yard, where I was dumping the cuts. The inner pulley was attached to a branch on the tree I was in, out on a large horizontal limb... the RnW was just above my head, near the main stem. All of the MA portion of the setup started at the end of the house and was in the open area of the front yard, so the cut pieces traveled between the fence and house and were dumped in the front yard, right on the sidewalk. Made it easy to haul it all to the trailer.

The control you get with this setup makes it worth the extra work of setting it up, if you really need to move the pieces slowly and not break stuff. With a speedline, I would have been tearing up the lawn and possibly broken the sidewalk with the bigger pieces. Even with a control line, the pieces are bouncing around a lot with a speedline, so I like this better in tight quarters.
 
Just thinking later it bubbled up from the recesses that my doubling up comment really should mean neglecting vectoring, it's a 2/3 to 1/3 loading split. Would you consider putting the 2/3 pulley by the trunk, putting the 1/3 redirect pulley out at the outer location and then redirect the single rope back along the branch to the friction device, maybe with a downward redirect. This would reverse the locations of the 2/3 and 1/3 loads, maybe useful if you have to operate on a lateral branch like the drawing.

A little extra fuss but opens up the safety margin. Makes sense? Hope I explained and didn't confuse my idea.

I like how you went to 3:1 vs a normal double whip.

Another thought, if the along branch rope actually angled upward from the branch to the redirect on the stem a little higher up the stem it relieves a little more load off the new 1/3 point. Even a little separation angle contributes.
I had the same thought. That's a lot of line going all over the place but the loads would work better if we only had one choice of limb.
 
Man I use this setup all the time without the wrench, but a porty down low. I feel almost nothing up top. I give it some slack up top and let it run down to the a favorable angle. I love this setup.
 

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