Page 191 - J. C. Turner - History and Science of Knots

CHAPTER 10

STUDIES ON THE BEHAVIOUR OF KNOTS

Charles Warner

Rope and cordage are amongst the oldest human artefacts, and knots are
an essential part of their use. Yet even now there are many aspects of their
function that are not at all well understood. The main emphasis in this essay is
on the behaviour under load of single-stranded knots tied in fibre rope. I have
nothing on splices or other multi-strand knots, nothing on decorative knots,
nothing on wire rope. The properties of unknotted rope are described only
briefly, to aid understanding of the properties of knots. Monofilament lines
of various kinds are used principally by surgeons and by anglers. Surgeons'
knots are tied in very specialised materials, and are chosen mainly for ease
of tying in their specialised conditions; many studies have been made on the
practical behaviour of these knots, particularly on their security, but I do not
discuss them here because they do not seem readily applicable to the kind of
knot that is my main concern. To a large extent, the same applies to anglers'
knots, but the study of their behaviour made by Barnes [7] raises some topics
interesting to the general knot tier that I will briefly discuss.

Rope

Ropes function primarily to transmit tensile forces from one point to another.
The tension may be almost wholly static, as in a binding or lashing, or very
dynamic, surging, bending or weaving about as in oil-well drilling, roping
steers, or traversing cliff faces. Specialist ropes may be made for specialist
purposes, but most have to be able to withstand a wide variety of stresses,
including those in knots. Ropes in use suffer a number of basic forces. There
are tensile pulls on the whole rope and all its constituents, strands, yarns, fibres
etc. Except for the straight longitudinal fibres in the core of some kinds of

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