Lovely symmetry, but virtually zero ability to transfer vertical force on the horizontal poles into the vertical pole (or any other combination), and no mechanism to leverage cord tension.
Was your challenge intended to be functional or simply decorative?
Derek
Just a thought or perhaps a question:
If you have three poles of circular cross-section at an x,y,z locus, then perhaps the joining material/fiber should be ribbon-like in cross-section to obtain the greatest frictive resistance? It could be a flat ribbon (woven) or a sennit covered with pine tar (I love pine tar) to help increase the friction. Otherwise it seems that one should alter the shape of the meeting point(s) of the poles to allow/encourage some mechanical attachment or resistance to movement, one to the other? FWIW ???
SR
You’re trying to defy the laws of physics if this contraption is for practical use and you’re NOT using multiple wraps of rope. No further explanation, I would be repeating myself.
I had never thought of adding a third material, solid or liquid, that could help increase the friction between the rope and the pole ! Is the addition - of pine tar or whatever - a known knotting practice that I was not aware of ?Hi xarax, The use of pine tar as a preservative of natural fiber line acts also to form an adhesion to underlying surfaces. In particular note the use of the selvagee (SEL-vah-jee) from ABOK #3521, that was found to adhere with much improved force when made with spun-yarn or marline that had been well-soaked in tar, a practice I use to this day (well, tomorrow, at my weekly volunteer rigging) to obtain a purchase on a shroud prior to adjusting the tension in the lanyard through the dead-eye. As for the use of tar with other knots - it may well be that tar was used as a preservative that was also found to have side benefits, not the least of which is the adorable smell! Another practice that is used aboard ship is the parcelling of the shroud prior to applying the serving or service. A similar layer is added under wire seizings made on shrouds and stays. There may be more in other fields, such as rosin on pulling cable for electrical wiring or cabling and the use of chalk on climbing ropes. Specifically are they designed to help a knot? That depends on what one would term a knot, doesn't it? If a knot is any confusion for some specific purpose or otherwise in a line then - maybe; but if a knot is simply a deliberate tangle in a line then perhaps not! Maybe that is a discussion for another topic?
SR
" I believe/hope that this can be achieved by hard tensioning of the two riding turns per pole, and/or by more than two riding turns per pole, so that these turns function like they do in friction hitches."
Yes, we can always turn to ‘More Rope’ for a feel good or partial solution
http://knotbox1.pbworks.com/w/file/fetch/8097439/JobKnot.jpg
But I hope you are seeking an intelligent solution rather than ‘saturation knotting’. This little example would have been so much better tied with a Gleipnir or the more recent ‘Xarax Knot with no name a la Gleipnir’.
So, back to the tripoles.
For nothing more than artistic bondage, the delightful manifold you have given us or the basic manifold used by the scouts in another thread are ideal. But for a ‘real’ application, the nature of the materials and the nature, magnitude and direction of the forces involved are critical aspects. Surely the binding chosen must accommodate the requirements of the(a) ‘real’ application.
If it is a table, then not only must the binding handle the vertical forces, but it must also resist the horizontal force of being leaned against and so resist parallelogram style deformation (presumably we are not allowed the luxury of diagonal spars or spoke ties?).
The use of Tar soaked cord raises a significant question - might I presume that this challenge must achieve the desired goal without adhesive? Tar soaked cord today, Superglue or Araldite soaked cord tomorrow and resin soaked carbon fibre for the final solution?
Derek
xarax,
Thanks for the invitation to post to this subject. I’m afraid that I’d take the traditional process of applying two, adjacent square lashings. One between the vertical (with the vertical spar perpendicular to support surface) and bottom most horizontal spar; the other between the bottom most horizontal and 2nd horizontal spar with the 2nd spar positioned (supported) on top of the bottom horizontal spar. Can be done with one piece of line and there remains sufficient room between the spars for frapping the 2nd lashing.
The above assumes that additional supporting structure will provide lateral support to the vertical spar.
That said, where slick spars, heavy traffic, working due to wind (from experience), etc. are involved the lashing between the bottom-most horizontal spar and vertical spar tends to slip. One solution, when the vertical spar extends sufficiently beyond & above the two horizontal spar, is to provide suspension support to the bottom most horizontal spar by applying an Icicle Hitch to the vertical spar with the “load” end secured and tensioned to the bottom-most horizontal spar. A taut-line hitch can be used to provide adjustable tension.
The idea of using a constrictor knot, as suggested by one poster, around one of the spars instead of a clove hitch to start a lashing is a good one. In the above it would be the starting “knot” applied to the vertical spar, just below the bottom-most horizontal spar.
SaltyCracker
(formerly KnotInGuild… felt that name a bit glib.)
… intended to reference a Wagoner’s Hitch to provide adjustable tension rather than a Tautline Hitch.
Hi, can you advise how this lashing is done?
Thanks.
Your photos are cool but I cannot figure out how to actually make this lashing… and video?