Page 70 - The Complete Rigger’s Apprentice

CHAPTER 3

Friction, Part 1: Knotting

“If you can’t tie a knot, tie a lot.”
—Anonymous

Every knot is an exercise in friction; bends, belays, of rope, loops, etc.) and detailed the best examples
splices, and seizings all are secure to the extent that of those types that I know.
they make a line stick against itself when under Some cautionary words: Since hundreds or even
strain. thousands of pounds of pressure might come to bear
If this were all there were to knotting, there’d be on the knots you tie, it is well to be sure of the fin-
no art to it, but rope in use needs to be untied nearly ished product. As Clifford Ashley put it, “A knot is
as frequently as it is tied, and we are faced with the never nearly right; it is either exactly right or it is
conflicting needs of maximum friction when tension hopelessly wrong, one or the other; there is nothing
is on, for security, and minimum friction when ten- in between. This is not the impossibly high stan-
sion is off, so that we can untie. There are excep- dard of the idealist, it is a mere fact for the realist
tions—and there are other desirable qualities—but to face. In a knot of eight crossings, which is about
it is this selective friction which best characterizes the average-size knot, there are 256 ‘over-and-un-
good knots. der’ arrangements possible. Make only one change in
Many different knots have evolved to meet this ‘over-and-under’ sequence and either an entirely
many different situations and rope types. For exam- different knot is made or no knot at all may result.”
ple, several of the knots in this chapter are relatively I might add that some seemingly fussy details
new, invented to deal with modern synthetic rope, can make a significant difference; drawing up in a
which is slicker than manila or hemp. Rope flexi- certain way, or stopping to fair a knot while in the
bility also varies widely, as do the sizes, shapes, and process of tying it, can mean the difference between
consistencies of the objects to which it is attached. security and failure. Furthermore, today’s sailors
And a knot that is good for one situation might need to understand that HM fibers (Spectra, Vec-
prove inappropriate when used in another; use of tran, etc.) are very, very slick; most knots will just
a Bowline where hitches or an Eyesplice are bet- crawl right out of them, at loads as low as 10 percent
ter choices is a classic example. Given this range of breaking strength. The few knots that won’t slip
of requirements, it is in the rigger’s best interest to will usually weaken the rope by at least 60 percent.
have a healthy tying vocabulary. In this chapter I Splice HM rope. “High Modulus” (HM) is a fairly
have listed several basic types of knots (bends, end arbitrary term. Mushy even. But fibers regarded as

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