Author Question: Strangulation Knot

[jmalikauthor]

I'm a fantasy author. A minor plot point in a book I'm writing involves a slow strangulation by a knot that tightens incrementally over the course of an afternoon.

Is it feasible? What would such a knot look like? Even theoretically?

If this is not feasible, I'll let the plot point go.

FWIW I'm a former Boy Scout, an avid sailor, and I attended the French Foreign Legion Desert Commando School. I know a fair bit about knots, but not to the extent of the people on this forum. My hat is off to you all.

[SS369]

Good day jmalikauthor.

I don?t think that this is an appropriate topic for the Guild forum. If you are writing fantasy, just insinuate, in your story, what it is what you want. You don?t need ?reality?.

In theory, knots don?t tighten all by themselves.

SS369

[DerekSmith]

Although strangulation is not a topic I would be happy discussing, even being it for a fictional scenario.  However, there are a number of situations where a knot acted much like the ratchet on a cable tie would be valuable.  Naturally it would probably be impossible to untie such a knot, but although I hate the concept of making a knot that can only be removed by destroying it, it does pose a design challenge for the knot aficionados that ruminate through these pages.

So, what knots or knot components do we have that flow relatively freely in one direction but readily jam in the opposite direction?

The sliding grip hitches eg Prussik or the self locking Gleipnir (Dahm knot) spring to mind.  But what would other knot botherers turn to in order to generate a knot ratchet?

Derek

[KC]

Shrinkage from wet, tight like leather as power source of movement is all i can think of.
.
Can design knot to be unforgiving in any ground taken, but the actual motion to take ground, self-powered a different story.

[James Petersen]

The mechanism you seem to be talking about sounds like the (bent metal) running eye of a wire cable snare. These snares are made from material very similar, if not identical to bicycle brake cable. (There are also tent guy line tensioners that work on the same principle, albeit in reverse.) Snares work because they are fixed to an anchor, and the victim has no hands (or no hands free/available) with which to loosen the noose, which can therefore only tighten.

Not a knot, I know, but might be of some use.

-JP

[mcjtom]

Shrinkage from wet, tight like leather as power source of movement is all i can think of.

Nylon ropes seem to stretch when wet, but then shrink to beyond the original length when dried, I think.  Here is Petzl bit on that, but I can't find a good paper that would test and explain the phenomenon in greater detail

https://m.petzl.com/GB/en/Professional/Washing-a-new-low-stretch-rope-before-use?ActivityName=Rope-access-and-confined-space