Page 153 - J. C. Turner - History and Science of Knots

Knots at Sea 143

emphasis on the most used knots, is shifted from a knotting discipline directly
related to security of driving their ships safely across the sea to that of work
and money. At sea their time is sparse, which is witnessed by the lack of
knotted arts produced by fishermen.
Concerning their knots, general observations to be made are three-fold:

(i) Knots have to fulfil criteria in their production, man-handling and main-
tenance. In fishing it is generally the sheer numerical magnitude of the
times a knot has to be realised, which plays a role. Longlining involves
thousands of hooks attached to a groundrope, and trawling demands at
least equally many netknots to create meshes. Hence the knots fishermen
tend to employ are usually extremely effective solutions to encountered
rope problems. During their careers they would have to tie them innu-
merable times, thus creating a harsh `simplicity criterion', which is an
optimalisation of structural and algorithmical simplicity combined with
functional effectiveness.

(ii) The dynamics of a fish catching system causes the extensive use of slipped
(temporary) but reliable knots. The Slip Knot commonly appears as an
elaboration of other knots and is meant to ensure easy opening. It is as
such usually not more than an extra tuck with a bight of the working
end, often followed by a `locking security'. In general these operations
do not affect the working of the knot negatively, but result in some other
useful actions. First of all the slipped segment toggles the knot, prevent-
ing it from drawing up tight into a nipped compact mass. Secondly it
provides a part on which one can exert tension when opening the knot
after it has been put to use. Thirdly it offers `locking facilities'. The
Codline Knot is an advanced solution to all of these demands and also
it suitably illustrates which evolutionary forces knots used by fishermen
are susceptible to.

(iii) The impact of synthetics on knotting has been great. The nature of arti-
ficial fibres requires knots with a high resistance to slip. This is an area
of fishing where some rope problems have undergone quite spectacular
changes to their solutions, but we shall see that in industrial fishing,
frictional problems have been solved in a quite different manner.

Fishermen's knots constitute an enormously broad subject and the con-
text of this treatise is too confined to give a complete picture. We shall restrict
ourselves to a few typical older knots such as used in longlining and gillnet-
ting, which the author collected from various museum fishing gear exhibits
and learnt during talks with senior fishermen.