Hei!
We got two poles/tree trunks and are going to tie a rope between them for tightrope walking. Well, something similar - we are going to climb the tightrope 
There are grown men weighing 240lbs climbing this line, so the system should be able to hold some weight. We want the rope to be tight as possible and it shouldnât be sliding down the poles.
Some drawing for a quik demonstration 
What kind of knots or rope systems would you suggest?
Take a look at this tighwire system:
http://www.stormbound.org/tightrope.html#How_I_set_up
My personal interest lies in slackwire, where the tension on the wire is only provided by the load (e.g., the performer). The difference is that to balance on a tightwire the performer must keep his center of mass above his feet, while on a slackwire he moves the wire with his balance to under his center of mass. A slackwire is substantially easier to setup and more fun.
Thanks for your reply knot4u
I know the topic title and drawing makes the entire thing a bit confusing. What I want is more like a climbing line than a walking/balancing line, and the language barrier is making it a bit hard to explain.
1:07 in this video: http://www.youtube.com/watch?v=tFw6fulmeYY&feature=related
In the Scandinavian languages this is called âarmgangâ. Arm walking directly translated
The rope doesnât have to be extremely tight, but tight enough to not make the downhills and uphills of the rope too steep. The setup shouldnât be too complex.
If itâs possible to make the rope tight enough with a sailors hitch, roundturn and two half hitches or a tensionless hitch, I will use those. What do you use for your slacklines, knot4u?
That Evolution race looks cool! I wonder if there is anything like that in America. The obstacles are not too much different than my workout exercises.
That rope at 1:07 is more like a slackline and less like a tightrope Do a search for âslackline setupâ on Youtube:
http://www.youtube.com/results?search_query=slackline+setup&aq=f
There are many ways to setup an adequate slackline. The allowable margin of error is rather large! Hereâs a method I have tried that works fine:
http://www.youtube.com/watch?v=18qbgwCn2ZA
If using rope, instead of webbing, you could easily replace those carabiners with appropriate loops.
EDIT:
Thanks for pointing me to this video. Itâs basically systems we already know. He uses one piece of rope, to make a roundturn around the tree and then connects the two ends. He connects this piece of rope to his balancing line. He makes a similar setup on the other end of the rope, but uses double loops on the balancing line, double loops on the rope on the tree trunk and connects them in a hauling system.
He makes the haling system by taking the working end on the balancing line through the first loop at the tree trunk, then through the first loop on the balancing line, then through the second loop at the tree trunk and then through the second loop at the balancing line. This makes a hauling system, 4:1 he says in the video. Pull real tight and finnish off with three half hitches.
To me, the only option for a double loop on the balancing line will be the double butterfly loop. Double splayed loops, double bowline or figure eight double loops might capsize or disfigure the knot if you pull the ends in opposite directions like this, right?
Looks like a quik and simple enough setup.
Thanks 
You can use double loops if you want, but thatâs not automatically necessary. That portion of his system is kind of like a Versatackle. You can use a Span Loop (or a Butterfly or another suitable loop) on each side of the Versatackle.
I think itâs figure D or E of these hauling systems he is trying to achieve with the double loops.
http://www.brrr.ws/docs/Boat_Rescue_Haul_Systems_files/image004.jpg
He passes the rope through one and one carabiner forth and back. Not through two and two. The Versatackle is self locking, but here he is using a tripple hitch to finish the knot off. I also believe figure D gives a greater mechincal advantage than the versatackle.
Verstackle-like perhaps, but I donât believe heâs doing the versatackle in the video
Figures D and E give a greater mechanical advantage than the system in the video. In Figures D and E, the two caribiners arenât splitting a force at one point (nominal MA = 6:1). In contrast, in the video, the doubled carabiners split a load at one point (nominal MA = 5:1).
I just tied Figure F (nominal MA = 9:1). I tied a Slipped Buntline on the first anchor. I brought the rope around the second anchor. I used a Span Loop as the first pulley. I brought the rope around the second anchor again. I tied another Span Loop in the correct location for the second pulley. I was able to get substantially more tension than a regular Trucker Hitch rather easily. I was afraid of breaking the rope. In theory, you could continue that cascading of pulleys to get more and more mechanical advantage.
If you use a double loop at one point, then you do approximate the system in the video I posted. Youâre right that the video is not really a Versatackle. I just threw that out there for general understanding. You can use the double loops you suggested. However, a nice thing about a regular Versatackle is that itâs self-locking until you can tie things off, even though you lose some mechanical advantage due to friction.
Thank you for posting that diagram.
Hauling systems are indeed interesting, and it could be useful to memorize some of the systems in case of an emergency situation. Are you able to pull 150kg by your legs, you can pull 1.350kg (approximately ten times the weight) with system F. Just a long rope and a couple of loops on the bight is all that is needed..
The trucker hitch is figure B, which is 2:1
I know the versatackle outperforms the trucker hitch when it comes to mechanical advantage. But if it gives as much as 4:1, then I agree the versatackle will be a better option (because of the self locking feature) than what is shown in the video.
I just tied an approximation of your Figure FPretty cool that you took time to test one of the systems :)
You are right. On a trucker hitch you put the rope around two objects/anchor points, where the second one would be the first carabiner/pulley in figure C.
Seems like adding a lot of complexity for little mechanical advantage with double loops like in the video. Perhaps a versatackle with a finishing half hitch for security would be the best option after all.
Yes, a regular Trucker Hitch is a nominal 3:1 MA.
Correction for the video, that system is a nominal 5:1 mechanical advantage. (A closer inspection reveals 5 strands pulling at one point.) Thatâs not a bad option. Sometimes the system in Figure F (9:1 nominal MA) is not feasible.
If you really want to tension-up with a Truckerâs Hitch, I found this modification works brilliantly - using âthimblesâ usually intended for wire rope.
http://www.weldsmith.co.uk/tech/edn/0901_BCweldcourse_present/tofino_wagonhitch_1pg.html
The âfixedâ thimbled loop to the LHS of the pic is formed with a 3 turns Jack Ketchâs hitch. It works very very well. Good legitimate use for hitch which isnât recognised in this short compact form.
It really seems perfect. The âthimbledâ first cascade has very low friction enabling drawing-up, while the second cascade has high friction to lock it. You can âswigâ the rope between the first and second cascade - alternately tighten and pull sideways - to really tighten the inner âthimbledâ cascade. A single person can do it to a high tension.
Another option for reducing friction is using real sheaves:
http://i51.tinypic.com/2133yqb.jpg
(pic by member Benboncan)
http://www.flickr.com/photos/benboncan/5360273853/
A downside is having to carry around sheaves big enough for the thick rope required for the original poster.
Hereâs a useful thread for other methods for reducing friction:
http://igkt.net/sm/index.php?topic=2812.0
Iâve tried setting the system up with a versatackle.
I anchored the main rope with a timber hitch around the first tree trunk. Then I picked a short piece of rope with one eye splice in each end. I put it around (round turn) the second tree trunk and put the main rope through both eyes (the splices).
From here I tied the versatackle and finished it off with three half hitches for security. The locking feature of the versatackle was very helpful in getting the rope really tight.
The short rope was softer than the main rope, so I got some visible wear and tear in the eye splices.
Hi âtrade use onlyâ - are you the R D Smith of Weldsmith fame? If your are, then this is a brilliant piece of extending rope functionality - if you arenât, then great find and thanks for bringing it to us.
I am particularly interested in rope âmachinesâ such as the Truckers Hitch and the like, especially their points of weakness and ways to reduce those weaknesses (jamming, wear, reduction in rope strength etc.) so your thimbled Truckers Hirch immediately grabbed my attention.
The use of a JK noose for the ârootâ thimble is a stroke of pure genius, in that the loaded line retains virtually 100% of its strength as it sheds load frictionally into the thimble before creating a collar to terminate and hold any residual force on its terminating end. This termination is so perfect, it should be part of every rope users toolkit and if it doesnât already have a name it should be called the Weldsmith Eye or perhaps the Tofino Eye. I would hazard a guess that if we were to look closer at this termination we might find it to be superior even to the spliced eye which suffers from the weakness of expanding under load.
My attention then turned to the first cascade thimble loop which is stated as being made âin the standard wayâ, however, it looks like a simple slipped overhand which immediately made me think âweak spotâ - then I realised that the slipped OH is essentially a zero wrap JK and that the 100% loading that comes into this thimble is spent in exactly the same way as in the âTofino Eyeâ. What is more, the OH portion of this fixing only takes << 50% of the loading, so it also is not a weak point.
The only tiny grumble left is that if during use a large force is put onto the assembly, then the OH portion of the zero wrap JK is likely to jam tight and resist disassembly (shame we donât have the equivalent of a slipped Carrick).
Derek
D R Smith
What the noose will shed around the thimble will depend on
materials. You might notice that elsewhere it has been asserted
that eye splices are quite strong in this rope, and generally,
so conjecturing that the noose hitch will even equal them
is reaching beyond the pale, IMO. (It would otherwise be
a convenient way to terminate the very strong but slippery
HMPE 12-strand cordage.)
I tried this with 3/8"(5/16"?) soft nylon solid braid around
a 'biner/krab, and the knot got tight, esp. at the point of
SPart entry; the load was not all that great.
I am suspect of the knotâs integrity, under high load --âhighâ
being beyond normal Working-Load Limits, though. Still,
this is somewhat like the (one possible dressing of the) Uni
knot which is said to be strong.
My attention then turned to the first cascade thimble loop which is stated as being made [i]'in the standard way',[/i] however, it looks like a simple [i]slipped overhand[/i] which immediately made me think 'weak spot'
And you are quite right, here --âthenâ you ought to have stopped!
But you continued âŚ
- then I realised that the [i]slipped OH[/i] is essentially a [u][i]zero wrap JK[/i][/u] and that the 100% loading that comes into this thimble is spent in exactly the same way as in the 'Tofino Eye'.
No,
Your point however can be realized by tying it UNusually
(or an innocent mistake can become âbrilliantâ, perhaps!).
Given that there is the thimble to form a rigid
âi.p., NON-shrinking-- eye, one might well follow your
lead here and do so,
âŚ
The only tiny grumble left is that if during use a large force is put onto the assembly, then the OH portion of the zero wrap JK [u]is likely to jam tight and resist disassembly [/u]... which has the gain of being much more easily loosened! :) --tested in 3/8"- soft nylon solid braid, w/'biner vice thimble.
What is more, the OH portion of this fixing only takes << 50% of the loading, so it also is not a weak point.
Hereâs where theory & actual-factuals make for tricky figuring.
In theory, the haul lineâs equally tensioned on its in/out/back
trio of parts, so the thimbled have 2X, the OH tail X ;
actual-factual runs down haul-line tension by friction, so in
fact that tail sees less. (â<< 50%â I suppose doubly points
to this, fair enough.) Then, again, there is the question of
how much force rounds the thimble into this OH --still
looking good, though. But one might be even more concerned
about the knot integrity being hauled againse the gradual
expansion of the pointed thimbleâd eye end (rather than
the rounded metal of an oval 'biner, as I tried) ⌠!?
Rather than edit in what I forgot to mention, as it applies to an aspect
not discussed by Derek, I thought that the stability of the Torfino
structure around smooth metal was suspect : but I got no movement
with the base structure (just one 2:1 sheave) with a couple ropes
around painted metal, and 'biners, so ⌠stable it is!
Have you got a better photo than this one then Dan,
http://www.weldsmith.co.uk/tech/edn/0901_BCweldcourse_present/rig_pix/tofinomod_wagoners_218.jpg
because, I am finding it hard to see just what the photo shows, and although weldsmith says - âthe secondary loop is made in the usual wayâ - he then goes on to say the âloopââis drawn up around the thimbleâ - suggesting that it is in fact a slip knot nooseâŚ
I think that as weldsmith has shown incredible ingenuity in designing this variant of an old favourite, he will have seen the value of having the loaded line run straight into the thimble in the, as you put it, the UNusual wayâŚ
Derek