Hi All
Suppose we have a triangular platform with ropes securely fixed to each corner. We also have a rope coming down off a tree branch and we’d like to attach the three ropes to it and haul the platform up. The three ropes are not long enough to reach the branch but have a good amount of working length. The descending rope is strong enough to hold the platform. The ropes are all similar diameters.
Is there a bend that will solve this problem?
An eye knot on each, then connected by the hauling rope with another eye knot.
This sort of problem occurs in commercial fishing
with conch/whelk pots that are circular sections
of 55gal plastic drums (or the like) : one has 3
pot bridles to join to a snood/gangion/ line (which
might be hitched to a long line / trawl).
((There’s another pot design where the cut section
of drum is formed into an oval, open at one top
end, and a 2-leg bridle hauls it up in vertical length.))
An easy solution is to use two ropes --one, double
the needed length of a bridle leg, this size the other–
and attach to each of the three tie-in points on the
pot, then form an overhand eye knot in the bight of
the doubLEngth rope and join the 3 leg to that,
and the snood to the eye by any number of ways.
What I’ve never seen, though what seems obvious
to me to do, is to hold the doubled rope’s bight center
and the single 3rd leg together when making the
overhand knot.
Otherwise, there are all sorts of fun ways to bend
3-to-1, such as using the blood knot structure e.g.!
Question comes from something I saw on the telly.
A guy in the jungle of Guatemala built a triangular sleeping platform from branches and vines. Apparently he wanted to be out of reach of jaguars, though I hear volvo drivers are more dangerous to people on foot.
He holds up the ends coming from each corner above his head, so they must have been about 8ft long, and explains that he just needs to join them to a vine thrown over a branch. “I wonder how he’s going to do that,” I asked myself, but I was not to be enlightened because it then cut to him after dusk, hauling up his platform in silhouette.
The vine must have been strong and flexible, perhaps enough to make a loop. Not sure though I would like that degree of point loading on vines. I was sort of hoping there was a super-duper multi-strand bend I didn’t know about.
If limited to common knots I’d probably go for a triple sheet bend - least twisting of the vine and under continuous load it should hold.
Mutli-leg Sheet Bend is what asking about? Multi-bights or eyes to 1 lock?
.
Might also try 3 legs to metal ring/clevis etc., then a main to top of ring etc.
Might try legs around metal and friction hitch back to selves for adjustments to level even after perhaps uneven stretching.
simple sheet bights do present this also, not as cleanly.
.
Might try main to 1 corner of platform and friction hitch center of 2nd rope to main and use the ends as final 2 legs of support, but prefer main thicker for that. Perhaps better to have individual friction hitches to a main of same diameter.
Well, yes, one should be concerned about tying
(bending) with vines --those from the corners
of the platform, and the one going over the tree
branch.
Well, it occurs to me to weave the trio of platform
vines into a common sinnet/plait (as girls do for hair),
and then to reeve-splice into that with the single,
opposed vine. Hope for friction gripping w/o any
sharp bends; the tails might be simply turned and
tucked, making largish --not hauled-snug-- arcs,
yet adequate to stem slippage!?
I think that such a structure can be formed with
only gradual bends, lots of material contact, and
… it would work!
(And then the fellow will mark history by having
his downfall not from the big cat but some plant-loving,
vine-eating animal, maybe one of the jaguar’s prey,
a peccary!)
Well, yes, one should be concerned about tying (bending) with vines --those from the corners of the platform, and the one going over the tree branch.
I did catch a glimse of one of the corners: lots of wrapping turns.
I’ll see if I can figure out how to get a snapshot from a DVD video.
You could try playing the DVD in a computer and then taking a screenshot.
The first thing that comes to my mind, since is to tie the corner ropes to the vine using a prohaska/blake’s hitch, or some other such gripping hitch/knot. This would have the advantage of not requiring the descending vine to be into tight (any) angles. One would also presume that preserving the strength of the descending vine (weakening it as little as possible through knotting) would be of paramount importance.
JP
I believe that any knot around a vine will fail due to bark stripping off, if still live, or the vine just breaking, if dead.
The original post asked about using rope and now we have gone to vines and branches.
Maybe just tie oneself to the trunk on a branch.
Although some animals can climb and jump pretty far…
SS
I shouldn’t have revealed the context because the question is not about vines.
I saw someone doing something and I wondered (just wondered, don’t have an application) how he did it, and that thought led me to wonder if there were a bend (not a work-around using loops) specifically for multiple strands to one strand.
I thought “Suppose we have …” clearly indicated it was a theoretical question, but I’ll be more explicit in future.
If there had been such a bend I would have been pleased to have discovered it, but it seems there isn’t.
Oh, but there ARE such bends (as I indicated above).
It’s less a full-throated “discovery” than an application
of how knots work and adapting to the circumstance.
But a 3-to-1 joint will likely be much of a sort of
hitching of the plurality to the singularity.
As for vines,
I happened to be dealing with some that are threatening
the well-being of trees --mostly English ivy, but some
other vines as well. So, I thought I’d have some time
playing with ropes, and attached w/a friction hitch
a 4:1 tackle composed of 2 shackles & 1 'biner,
and running cable-pulling tape (1,800# size).
I put a good bit of force on the vine, trying to pull it
out off of the tree (and so engaging its many arms
–an arm-y of small vinery).
Then I tried “sweating” (pulling sideways on the taut
tackled line) that attachment with another,
which line I sort of sat upon.
.:. one darn strong vine !!
(And two police officers answering an alert that
someone was erecting a tent … ! egadz!)