Best friction hitch for holding rigging loads

Brock Mayo

TreeHouser
Joined
Dec 3, 2012
Messages
171
Location
Cottage Grove, OR
Hey all,

I'm planning on using a portable winch (PCW5000) to move some laminated beams across a creek for a trail bridge rebuild. I'm looking for a friction hitch backup to self tend at the ground redirect going to the winch. This will most likely be a 5/8 inch block. I'm wondering what the strongest friction hitch is, and some recommended hitch cord that would work well with 1/2 inch stable braid? Also, how to get it to self tend smoothly with the larger opening on the block? The beams weigh 1120 lbs.
Or, is there a better way to back up the winch? Thanks!

Brock
IMG_2200.jpg
 
Plain old prussic loop, use 3 or 4 passes as needed. For 1/2 inch stable braid, I can agree with 1/2 inch tennex. Since it has a softer hand than the stable braid, it will grip well.
 
  • Thread Starter Thread Starter
  • #5
Nice, thanks guys. I've always thought of tenex hitch cords as not the best due to the lower melting point. But I guess that soft hand creates such a good grab that heat isn't the problem. I'll give it a go!
 
Pretty much any cord of equal or slightly smaller diameter that is soft enough to bite with the wraps, then just take as many turns as needed to hold. You could use 5 to 8 or more, French prussic. I've used a small tree to anchor the hitch when pulling with the skid loader, and drop a pulley in to make it self tending
 
i'd prefer round cord diameters range: 50-75% diameter of the host load line hitch grabs, 100% matching diams feels slippery.
DUAL RAT-TAIL (can't look up rite now at work) like for ships as stoppers after bollard reduces loading
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From our world:
i'd prefer more of a dual leg Frenchie type grab of VT, even Prussic, ICICLE etc., as closest relative to rat-tails used in rescue; even in muddy conditions, is said as best choice
rather than our single leg Friction Hitch (Taut,Blakes, Schwab, Knut etc.)
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In this usage; i think of it more as trying to descend on friction hitch in SRT than DdRT (when in slip phase)
>>In DdRT there is a solid leg of support load can flip to as other side expands like 2 lines holding load and 1 starts tearing(hitch side can then slip fairly unloaded)
>>In SRT there is no buddy line to take load while hitch slides, so must do FULLY LOADED>>more HEAT frictions!!!
>>more death grip, but more heats on slip
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i too can speak well for flat Tenex, round on pull, flat on wrap!
The flat profile on wrap gives less arched distortion in cord/ not leveraged 'weaker' as much as a round cord
>>around same arc has a larger 'humped' deformity so is distorted 'weaker' from max strength straight line
ALSO, the flat profile provides more grip surface area on the host load line than round 3/8" cord
When i first started playing with Tenex i had heat concerns and visualizations of a wider blanket not letting the heat out
>>this is not what i found when i went there tho, it seemed the flatter/thinner let heat out and the braid was looser to allow more heat escape
Had many cords, Tenex became fave!
>>seemed more glazing on round cord that concentrated loading to thin stripe of round cord contact on host
>>vs. the spreadout contact surface of Tenex flat around host load line under same load spread wider to host for less glazing!
i've only worked 3/8" Tenex.
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Mostly i've tried to show many would work here for single leg Friction Hitch:
main mechanic is a leading HH/Marl to pull along the length of the rope column, as would in pulling log ;
then enough grips/coils that would stop anything if pulled perpendicular to spar;
only with preceding HH/marl converter can now pull inline with spar or rope column
>>
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As go to a Frenchie/VT/Klem/Icicle type dual leg friction hitch, seems 15-30 degrees each leg of pull sits at gives enough grip compression to control .
Sine at 30degrees angle is 50% of leg tension inline is also pushing sideways; 2 legs 50% load each; half of which is sideways against the other
for several braids gives the grip seems!
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If any doubt, use more turns and 2 friction hitches in failsafe and shared loading positions.

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ABoK Lessons:Massive volume of wisdom handed down thru the sages
chap_26 pre-ramble:....But knotting is merely the application of certain mechanical principles, and a principle itself can hardly become obsolete
chapter_22: "Hitches to Masts, Rigging and Cable(Lengthwise Pulls)" is totally dedicated, as a separate consideration to pulls down length/not properly across host, and opens with: "To withstand a lengthwise pull without slipping is about the most that can be asked of a hitch. Great care must be exercised in tying the following series of knots, and the impossible must not he expected....".
>>This is to a lengthwise pull down a generic host column whether that column is wooden pole or lifeline etc.!
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Sorry for yet another early morning brain dump!
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Fore-planning : Hitch point determines high and low clearances needed in floating load;
But can be easier to work around obstacles or place if hitch point is closer to CoG forcePoint
>>personally would like positive hang in determined direction w/o to much inverting etc.,
>>but work-able by a man purposefully trying to 'handle it' on the pivot of it's hang if needed.
 
  • Thread Starter Thread Starter
  • #9
Thanks all, I've been wondering if a french prusik or VT would be better than a standard prusik for heavy static loading? Not necessarily with my situation with 1120lbs, but with heavier loads. All the friction hitch break testing I've run across was more geared toward climbing setups. Thanks treespyder for the detailed response. I never would've thought about the tenex flatness equating to more grab. Makes sense... You did loose me on the last paragraph about Fore-planning?
Kevin, any good ways to insure that the hitch can't get sucked into the block? I'm wondering if a pulley with tighter cheek plates would be a better option? I would hate to have my backup wreck the whole show...
 
A pulley with cheek plates designed for prussic minding is surely best...squared off corners on the lower edges of the cheeks. Also needs to be sized to hit the minding hitch...an overly large pulley (that is, one designed for running very much larger diameter lines than the one you are using) will pass the hitch no matter what shape the cheek plates are.
 
You won't be lowering a load with the hitch, so heat-sensitivity is not such an issue.

Tenex get used in MA systems.
 
Don't use a block, use a pulley with prussic minding qualities. the time it happened to me I was using a ISC rigging block and yeah it was a scary pain in the ass to fix the situation.
 
  • Thread Starter Thread Starter
  • #13
Thanks guys. I'll go with the pulley. Seems like the right sized ring floating between the hitch and the over sized block could do the tending job if needed. Not as solid as the right sized pulley though.
 
A large washer floating on the line right behind the prusik will help prevent that, plus, the flat surface of the water gives a more efficient advance of the prusik.
YES, needs pre-reeved but can go from there to many smooth devices that comb hitch and doesn't hang line; used a padlock 1x, to put on line as a quick edit after someone already setup long line etc. in place/working.
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... You did loose me on the last paragraph about Fore-planning?...
At destination/delivery point; especially, but really the whole ride:
Choose Hitch-Point on load frame as function of leverage on CoG
>>i'd typically go for about 2' from CoG so 1 end definitively heavier to hang predictably
>>and at delivery point a man can bulldog it around to angles to place easier, more ballast above hitch to make below hitch part lighter, and shorter; or by tag line remotely to highest part of load/to make it heavier to lift low end to angle etc. (careful with low grip situation)
Distinctly to the model imagery that hanging load from pivot is just weightless shell that gives handles to react on CoG forcepoint thru pivot
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Hitchpoint on end closer to disaster(especially non-round); hangs heavier/more positively/but not as lightly if need to spirit it around; and must lift higher for same ground clearance.
Hitchpoint too close to/at CoG gives most clearance but butterflies around too much,generally too lightly, so not as predictable handling.
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Dual leg grab on especially nonRound is nice, and gives more modular build, faster reload etc.
>>But perhaps Blue Round Turn around Load, then shackle back to Blue Standing Part is more secure ?
pure round is convex at all points pushing out evenly and firmly from center at all points
>>in comparison even square has some convex points of no grip and then also sharp corners while concentrating force to only those corners

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Rat Tails fave force imagery of rope use and heritage;
>>translates best to our dual-leg inline class of friction hitches (VT, French Prussic etc.)
>>i sift separately dual-leg more across pull class of Prussic, Schwab etc.
>>farthest from mono-leg more pull across types of Tautline, Blakes etc..
all mono legs seem to need some kind of Half Hitch type preceder that pulls across line;
>>Frenchie/VT class seem to pull more along the host line correctly,and with 2 legs of support.
beeswax on prussics refreshen, mite be good time to get a chunk if don't have
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cord diameters: many started on Tautline, Blakes etc. back to itself so matching diamters and materials.
>>but also matching loads/stiffness as far as hitch denting host
In dual leg type hitches, each leg half loaded to that of host
>>prefer smaller diam. 50-75% stiffer cord for best chance of 'denting'(?)host even tho ea.leg cord = 1/2 host tension
>>doesn't need to be as strong if half loaded, and less strength loss on arc if lower diam.cord
>>especially when pulling Frenchie/VT style along host column rather than clamping across host column like classic Prussic(dual leg) Taut(single leg) etc.
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As hybrid in between, still trying to sort def. on SailorGrip, Icicle etc. based dual leg that present some across force on host but also inline
>>these seem very favorable many uses to me. but many of these need tuned to personal usage, diameters and materials used in
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Personally i'd favor for this:
spin eye to eye cord w/krab in it for weight around host 8+ times
>>then bring that end back down to start and also reeve other eye on krab
>>stretch and work cord into VT type config of 3-4 turns crown and trailing twist of braids under
>>works well in most cords w/o too much torquing cord weaker
cords should be long enough to give a few braids under, nice V's favour ~30degree spread
>>can use Spock 'live long and prosper' salute as quick check of the 30 degree spread, that would be 15degrees deflection from center each
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alternatively to the opposite power of extreme
would go with Burnhams triple death choke prussic for clean simplicity, immediate clamping action, and the most deformity, now acting as a catch for line especially if after hitch has tension in line
>>i think all friction hitches work better if on line of tension, with no tension under hitch on host, so that fatter part of line makes shelf for hitch
i think 3rd story pull on host line tight after hitch would give most leveraged deformity to host ;so that if after hitch had some tension, so less shelf;deformity helps hold!
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But claiming also,more deformity in host is weaker, and also the prussic i believe tests out for purists at lower breaking strength
>>Frenchie/VT may give some more slip in trade; this in it self lowers forces in system.
So from graceful to bulldogging shituation, those are my votes!
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pix below:
Older 90'spic of some hitches in Tenex w/whatever mods playing with in that era
Same age, some hitches including Icicle/Sailor( perhaps best of class yet less known) and my own/My Ride mod (really like all 3 in Tenex;not shown)
new pic of olds-cool: to the rich heritage of rope handling and understanding; perhaps our most ancient in depth technology (pre-dating cooking etc.)
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VT%20variations.JPG

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Double%20Eye%20-%20Split%20Tail%20Friction%20Hitches.JPG

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rat-tail-sea-rescue-friction-hitch.jpg



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edit:My Ride (personal mod shown above) in Tenex, was my best fave for SELF-TENDING climbing hitch for my personal climbing load to the end.
1 handed lanyard adjustment:
i also have lanyard reeved thru side D that comb's VT type friction hitch that anchors to the D
>>BUT make sure hitch pulls correctly and evenly on D, the way that D was meant to take force!
i favor round cord, on a 3strand lanyard for that.
 
  • Thread Starter Thread Starter
  • #17
Wow, thanks again TreeSpyder. Makes sense balancing the beam closer to the center. You can't see them but I did thread a couple gate hinges/pole step kind of lags into the predrilled holes on the beams so if the sings slid they couldn't slide off. I was surprised, neither sling moved at all, and I picked the beam up vertically off the one spar. I'm hoping to find a couple eye bolts that fit the drilled holes to clean up the anchor points a bit. The boating rat tail info, was exactly what I was curious about. Also, I remember finding your hitch pictures about a decade ago when I was first looking into advanced hitches. The color change at the one end of the hitch cord is key to figuring out what is going on. Thanks for all your work over the years!
I think Butch might need to start developing a TreeSpyder translator app. I'm getting better, but I think I'm still only comprehending 80%. Thanks again everyone!
 
Kenny : :thumbup:
I find his posts have so much information in then I just read them over and over. Awesome pics and diagrams as usual man, thank you. Btw, that's the easiest and best showing of the icicle and gripping sailors hitch I've ever seen!
 
Thanx, glad there is this portal here to share thru!
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i remember starting like those around me, no belt, no rope(except fleaMarket one for occasional lowering!)
i remember first time i saw a guy climbing with rope and saddle for the city, researching arborist catalogs at library,my first candy store Sherril catalog
>>finding ISA bbs on dial-up on my 8088 green screen with my free 25hrs a mo. walmart internet; and feeling like i'd found my own people!
(start connection, unload truck; sign in, start shower, usually ready to go to isa bbs when got done, but then forum was slow...)
Eventually the bbs faded, just as internet was exploding size wise; and somehow more arbos found internet, and the 3 major forums sprouted over time.
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i'm glad put eye bolt or some kind of mechanical stop on loads; wanted to say even a stop nail, but tried to stick with scenario..
i wouldn't like an eye2eye sling with just single choke on loads, but the double grab of the whoopee is more positive as presented
>>but i think pull angle is not best, just the double grab makes it 'workable'
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But with deformity of eye bolt on the smooth load
>> would consider running Bowline below it; knot opposite side of load from eye bolt stop; then half hitch(es) preceding.
>>This too would give double grab, but also correct the angle of pull to more inline / not across load
could also just tie throw line from bolt to side of Whoopie opposite it's pull, just so Whoopie can't walk off job(or shift)
can even tie low on eye bolt and precede with 1,mebbe 2 Half Hitches to take the loading, seeing final eye bolt/Bowline/Clove etc.as just a finishing anchor/keeper, not the real load pull point.
>>can still make modular pre-sets with 'leashes' lift 1, have next pre-set for pull soon as rope comes back down; like do when using slings in tree and have pre-set waiting for ground control to pull line backup
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Would always keep the alignment part of the Half Hitch,but might change the anchoring Running Bowline to Pile Hitch, Clove etc.
>>Incidentally there is actually another form of Icicle Hitch, , that John Smith brought to an IGKT meeting in 1990, and tied on a tapered fid
>>and hung from it! (so states legend)


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i consider Icicle, Sailor Gripping(and my hybrid) lesser known, with very friendly properties, especially in Tenex.
>> these are tunable, and must be matched to your style, weight and materials i think; so may not work as predictably to start..
Specifically looking at bottom choke ring on Sailor and hybrid:
Other hitches use the bottom as a Half Hitch or Marl aligning precedent (to anchoring strategy of final knot);
>>that ALSO grips hard and unrestricted on host line; EXCEPT Sailor/hybrid,use other leg of line to clamp down and control the grip of the bottom Round turn, allowing the modified pull angle more properly, but i think tends easier as holds these bottom rings open somewhat
>>specifically exemplified in the hybrid is perhaps the ring(s) are tight loaded, but then pulled open a bit by the other leg of pull
>>imbuing in it's perfect storm like a solid self tending ring that is not totally choked closed; under the hitch!
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Pix have come a long way from kindergarten crayons on white page of msPaint
>>but always wanted to make animations of pix in head, not there yet!
FYI black background gives high contrast, BUT also:
>>all ropes etc. have a black even glow all around, not just shadow command from a given angle
>>black background makes the black gradient glow-shadows disappear; so only show properly when cross another item!
>>disappearing again as go over the black background/exiting the item.
Ropes are all white, with black glow inside for roundness, black glow outside for shadowing.
>>if tint red , tints shadowing too
>>but found if SUBTRACT Blue and Green from RGB: white - blue- green = red, but subtracting colors from black shading has no effect!
Voila red rope with rounded look and shadow that only shows shadow over other items on black background!
To make Yellow rope, just subtract blue to leave red and green(in RGB space makes yellow)
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edit: i all ways and always look at a loose rope as it's malleable form
>>tightening the line forges it to hardened form as long as tension force volume is maintained
Then consider pull angles etc. like rope was forged iron bar(s).
>>if 'twerk' angle funny in metal imagery, expect same from rope in it's forged usage
>>straight aligned, inline resistance to the loading pulls is always best
Thus, Pull Timber perpendicular to host across seating inline opposite side of load,but modify pull angle w/Half Hitch preceder to make Killick
>>so if pull inline with host/load resistance to pull is again inline as rope stop action other side of HH/inline to blue pull/rig line

But is still 'soft' in ratio of tensions; whereby basic 'Square' lesson of must be same diameter, so is matched on each nip side against host
>>then by extension if 100# on host line and hang load/self by single leg support friction hitch , will 'dent' host with full 100# input more than dual leg50# each denting 100# tensed host>> so would seek perhaps smaller, tighter diameter for cord on any, but most forgivable for all-in-one basic lifeline back to itself for Taut/Blake's as single leg 100# denting 100# line (for 200# man/load), but not as smart to use dual leg 50# each to dent same size line of 100#, Burnham's triple death choke prussic probably closest to exception, still rather go smaller cord diameter and tighter woven on softer fatter but more loaded host...
Perhaps Tenex footprint the exception to that model
Many simple lessons in the simplest of minimal barely making it lacings like Square;
>>precipice-ing between can and can't ; and what 1 change to make it a win always reveals pivotal points...
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My front license plate says ' born to climb, forced to work'; guess the fun part is over; gotta clock in !
 
  • Thread Starter Thread Starter
  • #20
Thanks Kenny. When your talking about the bowline with half hitches, would you use the end of the blue half inch stable braid, or some other anchor rope? That would be my normal tie off, but I was worried about the weak half hitches and the square corners on the beam... I had not thought about grabbing some bigger stable braid and tying it off. I've never used tenex that way, but I'm guessing it would also work tied in a half hitch to a running bowline?
Great license plate!
 
When flexing line would go with softer line that resists arc less;thereby is less leveraged.
Seems StableBraid is stiffer so would be weakened more on bend AND not seat as well, especially when only 4 corners grab,not 360degrees
Hard call on dealing with rectangle, always think rope should be grabbing round device pushing in to rope 100% around
>>anything less, is well, less!(already compromised to start)
i would seek to reeve line thru solid hole or to solid anchor bolt etc. for anchor on load, then 2 Half Hitch preceders to align force down column of load,and keep the impacts and main loading off of the main/final anchor.
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Hollow core Tenex is wonderful stuff for loads.
Loaded in air it is round, wrapped it is flat.
Flat doesn't stand as high as round when wrapped, there fore flat is leveraged weaker less, because less distortion/measured hump on that distorted/loaded axis.
BUT wouldn't run flat thru frictions to control load, especially ruff tree with looser strands of Tenex.
Round rope shines in handling, knotting and RUNNING rope, where webbing/flatter devices kinda fall flat(sometimes)!
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Would look for Half-Hitch preceding as ~50% efficiency left in line
>>common folk say the line is weaker; because it has less load capacity
>>really line isn't weaker, has the same total capacity, just the volume of force in rope device is not all to target
>>sidewards forces in line are not to target, but still count against rope capacity, so less target capacity remaining in line
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Flexibles(rope, chain, webbing, cable etc.) devices take on the 'tax' of sidewards forces for that particular position/angle of usage like rigid devices
>>BUT can not use those forces for support, just has the cost of sin (sine/sideways force) against your target cause/cos(columnSine/cosine) is my mnemonic
>>so i say not to let the cost of your sin, over-rule your cos(inline target) as perhaps (mostly unherd) political advice!
Rigid devices(wood, pipe, iron etc.) also take on the sidewards tax of usage at angle, BUT they can use those forces to also support load.
Rigid devices resist/thereby support on the inline and cross-ways axises, and in both the compression and tension direction on those loaded axises.
Flexible devices only resist/support on the inline axis, and only in the tension direction on that singular axis
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cos @ Zer0 deflection is 1, so 100% of force volume/tensions in rope device is to target when rope is PURE INLINE;
cos @ 30 degrees deflection/distortion is .8666 so 86.66% of line tension is usable to target
>>amazingly the sin @30 degrees is .5/50%of rope tension trying to bend hook sideways on truck, pull you off balance on limb etc.
i think logically, knot 'strength'/efficiencies is simply the cosine/columnSine(my wording) left in the line with the distortion angles in the knot
(kinda wouldn't call that a popular theory...).
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Didn't go to school for this, these are just what i researched and named and mentally cartooned these patterns while riding the 'nylon highway'(actually stole that one from title of excellent rope caving magazine).
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  • #22
Man, Just started looking at the nylon highway links. So many crazy bowlines and looks to be some good break testing results of progress capture devices. The tandem prusik seems hard to beat...
 
Yes, proper spacing is best!
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Curiously, the International Guild of Knot Tyers has noted Taut Lint as one of the most unreliable knots in AboK;
kinda suggested they were doing it wrong or wrong material tied in.
Not the most open minded group tho...
 
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