ropes and cordages

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ROPES & CORDAGES

PAGE 4

Added 2012 Jan 6th

OLDEST KNOWN KNOT IN THE WORLD ?

Here it is still keeping guard ! ( this is the original picture and I am using it under the
"fair quote" usage)

the rest of the document are mine in the sense that I did hard work to create them
using the original as starting point)

A close-up I made with Photoshop allows to see the details a bit better.

Another 'tweaking' made to yield more details.
Yet another 'tweaking'

Summary

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Added 2012 Jan 7th

TEXTILES INDUSTRIES YARN GLOSSARY

from fibres the equivalence with our "ropes" vocabulary
illustration

fibres == fibres

single yarn == YARN ---------first twisting procedure

plied (multiple ; folded) yarn == STRAND or sub-rope------second twisting procedure

'cord' or 'cabled yarn' or 'cable' ==HAWSER rope---------third twisting procedure and
first LAYing-UP phase

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Added 2012 Jan 8th

NATURAL FIBRES ORIENTATION AND ITS
CONSEQUENCES
see the topic just above prior to reading this one : you should have the clear notion that
"textiles" glossary is different from "rope making' glossary

FIBRE	Fibre Natural ORIENTATION	Plant part
COTTON COTON	not very marked ; can be S or Z depending on the source ^***	seed
FLAX LIN	S	bast
COIR noix de coco	S	fruit
RAMIE	very slight S (Z when mercerised)	bast
KAPOK	S and Z alternating helices. Brittle so usually is not spun	seed
SILK SOIE	S or Z silk is NOT directional - very long fibres 300 to 1000 yards
HEMP CHANVRE	Z (quite marked)	bast ( JUTE and KENNAF : light Z )
JUTE	light Z	bast
SISAL	Z	Leaf (Manille Gucca)
WOOL LAINE	not directional : crepelures in fact, and scales help the inter-locking instead of helices. When carded it is Z, when combed it is S	sheep hair

*** in
Studies on convolution of cotton fiber. [I]: Optical rotation analysis of cotton fibers
cultivated in various countries
Auteur(s) / Author(s)
UEHARA Masaki ; SAKAUE Asuka ; ONOGI Yoshihiko ;

[open quote]
Cotton fiber has its own complicated convolutions caused by helicoidal orientation of
cellulose fibrils in the secondary cell membrane. This helicoidal orientation has been deduced
to be caused by the earth's rotation during fibril development. To confirm this, the optical
rotation power of cotton fibers cultivated in various countries was measured using a
polarizing microscope. The optical rotation power of Z-type convolution parts in cotton
fibers cultivated in the northern hemisphere was greater than that of the S-type convolution
parts. On the other hand, for cotton fibers cultivated in the southern hemisphere, the optical
rotation power of the S-type convolution parts was greater than that of the Z-type parts.
This tendency was found to differ markedly for cotton fibers cultivated in areas located at
different distances from the equator. [end quote]

--------------------------------------------------------------------------------------

spinning is absolutely necessary to 'coalesce' short fibres in important lengths. The
'coalescence" is made by the interlocking of the helices in the fibres so my perception has
always be that you have to use reinforce those helices and their interlocking by going in the
same direction as the fibres naturally do and certainly not destroy or weaken this interlocking
by spinning in the opposite direction.

If yarns are not spun in the direction of the fibres have (when they have one ) then the laid-up
cordage will not be as stable a structure as it could have been and even in textile fabrics then
those will not take kindly to regular washing !

According to tradition yarns are always spun in the orientation given by the fibres.
This make sense as this help the gripping cohesion between fibres induced by spinning.

The more fibres and yarns are twisted the more they acquire "elasticity" or 'springiness' and
the more they tend to UNtwist.

It has always been my contention that twisting the fibres into yarns using the direction
opposite to the natural direction of the fibres is just structural non-sense and Darwinian
selection for the fittest results should have quickly selected for those avoiding structural
non-sense and this explain the usual tradition.

Plying ( grouping several yarns made of twisted fibres) of yarns yields an augmentation of
strength.Z yarns are S-plied and vice-versa.. plied==multiple==folded yarn
This what happen in rope making when making a STRAND or sub-rope from several
YARNS.

Most of the spun thread (single yarn) need a re-twisting, it is necessary to assemble several
of those single yarn to get optimal strength. ( 2 to 6 single yarn (fils) are assembled in a
plied yarn which is stronger.

For the spinning of single strands, may be probably, the direction is not always of a vast
importance (still why not be consistent , coherent and congruent and use the natural torsion
of the fibres ? ) but with 2 or more single yarns assembled then the direction of twist is really
most important.

his is the moment to say that functionnaly an S cordage is functionnaly equivalent to a
Z cordage IF AND ONLY IF there is a strict alternance of orientation of torsion between each
successive structural stages : yarn, strand, hawser, cable, super-cable.

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in www.cs.arizona.edu/patterns/weaving/monographs/tm_work.pdf
[open quote]
Flax rotates in an S-direction when drying. This intrinsic characteristic of the fibre most
probably explain why in Dynastic Egypt line is S-spun and Z-plied.
Cotton when moistened rotates much more than linen but it does so in all direction (my note :
convolutions ) it has been found that when "Z-spun Egyptian and India cotton can be washed
with comparatively little trouble whereas S-spun cotton tends to come apart"
[end quote]

For me this show that spinning contrary to the fibre's preferred direction lead to and inferior
product. "real life" spontaneous experiment will have soon by a sort of Darwinian survival of
the fittest selected for the better process.
Wool, does not rotates when moistened but they have scales that allow the inter-locking.
Traditionally carded combed are...

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in Prehistoric Textiles : The Development of Cloth in the Neolithic and Bronze...
by E.J.W.BARBER
[begin quote]"Now Egyptians linens as they have come down to us from dynastic Egypt are
invariably S-spun, whereas the threads in the textiles ( but those textiles are not specified as
linen! so comparability is not maintained, a cardinal sin) of the other areas around, especially
Europe and India, are typically Z-spun, starting with the textiles from around 600 B.C. at
Catal Hüyuk (Burham, 1965, 170)...Much ink has been consumed over the reason for this
difference of spin. Louisa Bellinger...has championed the position that the root of the
difference is to be sought in the fibers themselves ( I : AH: bravo Luise : so simple to
experiment and see the results and think Darwinian selection for the fittest way of doing
things ! ) (see esp Bellinger 1962, 6-10 and Bellinger 1965). It will be remembered from
Chapter I that flax fibers, when dampened, curl naturally to the left (S), whereas cotton
and hemp tend to twist the other way. While attempting to wash old textiles in the laboratory,
Bellinger found that the yarns spun in the same direction as the natural twist of the vegetable
fibers would hand together during washing, whereas those spun in a contrary fashion tend to
fall apart ( Bellinger, 1950, 1). She concluded that the ancient Egyptians had noted the
phenomenon and had for this reason come round to spin their flax, -their chief fiber for
millennia-always in the S direction, whereas the Indians for similar reasons had come to spin
their cotton in the Z direction and other people had followed accordingly (ibid)

Such an explanation does not, however, account for why the nations that used mostly wool
should have spun them so insistently in the Z direction ( my god this guy surprise me ! : wool
is not directional so it will accept either way ! and right-handed persons being the dominant
population of course there will be a dominance of the Z-spin unless a special processs makes
them better if with a S-spin ...carded fibres are to get a Z-spin, combed fibres to get a
S-spin) After all, wool has only a vectorless crimp, not a twist, and so can, be spun equally
satisfactorily in either direction.
...Bellinger suggest that the Z-spinners of wool musty have learned to spin from people who
were used to spinning cotton But that is unlikely on two counts. First, as we have seen, the
earliest evidence for the use of cotton in the Old World dates from the late 4th millennium,
whereas the wool industry was underlay in the Near East well before then. Second Ryder
claims that "the first cotton fibres had no twist" that " the twist of cotton fibres arose as a
mutation in a cultivated form" (Ryder, 1968, 78 ) -that is only after people were
accustomed to using it. It is true that hemp and nettle are Z fibers; their use started far to the
north of wool territory. It is flax that has the same initial territory as wool, and flax has a
natural S-twist.(me : transfer from the vast majority of right-handed persons and from cotton
using and any way the strength of the cotton twist must be really quite low as Earth rotation
is sufficient to influence itas with convolution there is equal opportunity for S and Z )
[end quote]

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in Science and civilisation in China : Chemistry and chemical...Volume 5 Partie 9

[open quote]Henry Hodges explained " if viewed from above, the movement of the spindle is
clockwise (then seen from under from the point of view of the spinner it is anti-clockwise :
see my chapter on frame of reference) the resulting thread will have spirals conforming to the
slope of the central part of the letter Z, and is referred to as Z-spun, or, by analogy with the
thread on the carpenter's screw, right-handed; while if the spindle is made to rotate in the
opposite direction, the resulting thread will be referred to as S(spun or left-handed"

The direction of rotation might well have been taken into consideration as soon as spinning
began. For instance, linen is a fibre of S or left-spun type, and this was the general spinning
direction of the material in Egypt and Mesopotamia, where linen is S-spun warps and wefts
has been found. Cotton was usually spun in a Z-direction, as can be seen from cotton finds
at Fostat. Yet though the natural spinning properties of the fibre material are important for
the spinning direction they should not be overestimated. Another important factor would be
whether the spinner was right-handed or left-handed. In thigh-rolling, and usually in spindle
spinning too, it is a rule a right-handed spinner produces a Z-spun yarn; a left-handed
spinner a S(spun yarn. Hodges has put it as follows : 'unusual spinning may thus be as much
a matter of personal idiosyncrasy as of a tradition stemming from the use of a different fibre
(still I find that this forgets the Darwinian selection of the fittest)

Hence we may summarize by saying that the best way to spin the fibres of the raw material
was in the spinning direction suitable to their natural disposition and the personal liking if the
spinner (that is IMO utterly myopic : forgetting the natural selection of the fittest product
yielded by a given twist applied to a given fibre : simple observation of results is quite
sufficient to explain 'things', bar some particular "magic" that could make that , say Z-spin is
considered as 'magic' and not to be used lightly for everyday items, even if it is the better
results : it would even give fuel to the belief that this example of Z-spin gives a better result
than an S-spin. )
[end quote]

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in Sails from the Roman port at Berenike, Egypt by Felicity C. Wild and John P; Wild

[open quote]
"The greater proportion of material considered here is of cotton, a situation without parallel
on site within the Roman Empire. The cottons can be divided into two distinct groups: the
one is woven exclusively from S or anticlockwise-spun yarns (S/S) , the other from Z-or
clockwise spun yarns ( Z/Z). Ancient spinners were highly conservative and the tradition in
Egypt and the neighbouring Roman provinces was for the S-direction. It would be fair to
assume that the S-spun cottons were produced within Egypt, where cotton-growth is
attested by the 1st century AD (Wild, 1997, 289-290). the Z-spun cotton are best
described as 'intrusive', but the weight of ancient literary and documentary evidence indicates
India to be the only practical source (Wild, 1997 ; Wild & Wild, 2000: 271-273). All the
cotton fragments discussed here were Z-spun and presumably imported. The linen fragments
were uniformly S-spun and presumably of Egyptian origin.

"The "Lyons" sail was of linen, S-spun, and presumably of local Egyptian manufacture.One
would have expect the ocean-going vessels constructed in Roman Egypt also to have had
linen sails, of which the pieces of S-spun flax webbing and largely..... A surprisingly high
proportion of the Berenike evidence, however, has been for sails of Z-spun cotton, a
material which it is argued above was imported, probably Indian, origin. The sailcloth, the
webbing, the rope and sewing thread, even the patching materials, are uniformly Z-spun,
indicating manufacture in India and /or the use of Indian materials for running repairs during
the voyage.
...
72 % of the Roman rope and cordage was ‘z’ spun. A third of the rope was in coarse grass
fibre, spun as either sz2 or sz3, in a range of diameters from thick string to rope. 17% of the
rope was in a stiffer, whole grass or reed with a variable spin, two thirds are ‘s’ spun
suggesting more than one production centre, and it would seem likely that one of these would
use reeds collected locally from Bir Ambagi. Other grasses included a curly tight spun grass
plied into zs3z2 or zs4z2, and a red ‘z’ spun silky fibre. 13% of the rope recorded was of a
fine fibred bast or cotton, with a regular ‘z’ spin in a variety of plies and qualities, though
mostly string dimensions. An exceptionally fine quality of this type was distinguished. A similar fibre
was used in nautical quality ropes with plies going up to zs2z3, in an assortment of spins
suggesting a variety of sources for these ropes. Several varieties of palm leaf ropes were
distinguished, including a very soft ‘z’ spun palm leaf fibre, a redder ‘s’ spun leaf, and a black
leaf that was mostly unspun and plaited.Roman Finds
Cordage ...

96% of the Islamic rope was ‘z’ spun. The most common type with 732 examples was a
rough grass plied into sz2 and sz3 in a variety of qualities and types. Two hundred and twenty two
examples were found of a stiffer reed or whole grass all with a base of sz2. These two types
make up 81% of all the rope found in an Islamic context. Of the bast or cotton based rope,
there were forty-eight examples of string, fairly equally divided into zs2 and sz2, and four
examples of a higher quality bast string. There were twenty-eight examples of thickly
constructed nautical ropein a wide variety of plies; mostly ‘s’ spun and all but three from
Trench 5.
[end quote]

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in Egyptian textiles by Rosalind Hall, Rosalind M. Hall

[open quote]
Most Egyptian thread is s-spun(anti-clockwise), doubtless because flax naturally rotates in
this direction when drying, although z-spun (clockwise) yarn is known. Two or more weak
threads were frequently twisted together, in opposite direction to that which they were spun,
to create a plied yarn (capital S or Z). The Egyptian spinners were skilful enough specifically
to produce a Z-plied yarn from s-spun thread for sewing purposes.
...
...all but three were made of cotton. This is interesting in view of the flax and wool in general
use in Egypt at the same period, but not unusual for for Nubia. All yarns are spun in the "s"
direction continuing a tradition going back to the beginning of weaving in Egypt. Where plied
yarns occur they are always s-spun, z-plied.
[end quote]

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Those authors seems so focused on "spinning"tools and habits rather than on "adaptation via
observation of the results" that they seem to forgot the inevitable "selection for the fittest" that
explain quite a lot.

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PRACTICAL FORENSIC MICROSCOPY : A LABORATORY MANUAL
by Barbara WHEELER, Lori J. WILSON link

The twist test distinguish S and Z twist fibres.
Heat wet fibres quickly over a hot plate and observe how they untwist.

"with this test, S-twist fibers (flax, ramie) turn clockwise whereas Z-twist fibers(hemp, jute,
abaca, sisal) turn anti-clockwise. Cotton and coir react irregularly (S)"

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Copyright 2005 Sept - Charles Hamel / Nautile -
Overall rewriting in August 2006 . Copyright renewed. 2007-2012 -(each year of existence)

Url : http://charles.hamel.free.fr/knots-and-cordages/