The Natural background for South American seafaring
Influence from other arts and crafts
Even if we don't know much from the maritime raft culture,
we know, that the cultures before and around, as well as the Inca-culture ware very keen to work in textiles, make ceramic, do stonework - they dominated some metals and they made beautiful wood cuttings. In some way, these abilities must have been a part of the condition for the maritime society. The question arises in which grade these handicrafts had their influence on the creation and construction of Balsa rafts. That we still don't know much about.
How did they ?
Neither we know much about how they cut their trees and worked the wood. They had no chainsaw - nothing like a saw at all. Machete, sword or sabre neither - nothing of iron. Axes and chisel of stone probably - or perhaps of bronze. Great things to investigate - and try out in work.
Wooden materials for rafts
Pretending to be copies of pre-columbian rafts, we observe an astonishing mix up by foreign cultures, bringing in an amount of irrelevant materials and anachronistic technologies
Balsa Wood is the lightest known wood,
and gives the buoyancy for the balsa-rafts. The Balsa tree grows in tropical and subtropical Central and South America.
The trees in Ecuador are most accessible because they grow on the west side of the Andes mountain range and therefor are easier
to bring to the sea (in general we must complain that in all South America there are very few navigable rivers going to the west side).
It is told us that the balsa tree (Ochroma Pyramidale) botanically is unisexual and in this way divided in male and female - where the female should be the best for rafts. This male/female relation has been impossible to get verified if it is a fairy tale or true - perhaps we talk about different variants of the same family of trees as include names as: Ochroma Lagopus, Ochroma Bicolor Rowlee, Ochroma Bolivianum Rowlee, Ochroma Concolor Rowlee, Ochroma Grandiflorum Rowlee, Ochroma Limonense Rowlee, Ochroma Obtusa Rowlee, Ochroma Peruvianum I.M. Johnst, and Ochroma Velutina Rowlee and Ochroma Tomentosum Humb.
Whether these are synonyms or indicate different species we neither know, but let a biologist answers for that.
Balsa-wood can absorb a good deal of water over the time. How long working life before getting waterlogged, we could estimate easily by experiment, plotting the lowering of a raft under a longer cruise - but that is until now not done.
The general name for Ochroma is 'balsa' - named after the Spanish word for 'raft'.
It seems now 70 years after Heyerdahl that the maximum peril isn't the waterlogging itself - but waterlogging in combination and as consequence of infestation with Shipworm.
At least the 6 of the last 20 wooden rafts sailing out on the Pacific Ocean were lost because of Teredo Navalis - eaten up in 2-3 month sailing in salt water - and more rafts so hard attacked, that they wouldn't have been able to return to their port of departure.
The Balsa flower is the reason for the scientific name: Ochroma Pyramidale
Balsa wood buoyancy
some of the old Spanish writers told us, was used for traverses, and that seems reasonable because Mangle Wood is a very hard and resistant wood. But probably more important: it is growing in the mangrove swamps along the coasts where the Balsa Rafts was born - therefor its most important point would be: a local growing wood, easy to get. It is logical, that they didn't arrange difficult transport from the mountains of ordinary wood for things so simple as traverses - they didn't own any carriage before arrival of the Europeans.
On the other side, to use balsa wood for traverses, could be an alternative idea - because balsa traverses at least offer extra buoyancy, if the main trunks go down. Heyerdahl did so - but the old people seems not to have done so.
As said: How the old South Americans cut down their trees and worked the material, that we still know much about.
Wood for Masts
An A-mast seems a common equipment to a Balsa raft
, even if the first glassplate-photos 125 years ago only show a mono-mast
An A-mast means a mast without need for shrouds, and that type of mast is standing more stable than a mast kept in position by some ropes. For us in Europa it is more stays and shrouds as the mast itself, as take the wind forces. Only very small masts stands without support.
For the Europeans we can inform, that neither pine nor eucalyptus was introduced in South America - then - and we have no reason to believe that the south americans had imported such - neither pine from Oregon. Eucalyptus as today is very loved in South America was still kept inside Australia, but arrived later as an insect resistant wood for use as sleepers for railways.
Of those reasons the old people didn't use those woods on their sailing balsa rafts. We don't know which wood they used, but probably a rather straight grown and slim local tree.
Thor Heyerdahl used Mangle wood for his A-mast on Kon-tiki.
The raft, the deck hut and the steer-system
Tar we use in Europa
for conservation of wood and ropes of plant-fibre and tar too protect against infestation by the wood-eating ship-worm Teredo Navalis. Eventually we use Tar mixed with linseed oil. And so did Heyerdahl.
With the many lost rafts in mind, we CAN'T recomend to sail out WITHOUT some protection against Teredo Navalis
We haven't heard about wood-tar extraction in pre-Columbian South America, but our question is: Had people other means?
We can't say anything with certainty, but one option seems to be NATURAL ASPHALT, as is found as tar pits, asphalt pit or rock asphalt around in the Andes Mountains. The only we can say, is: with that a protective asphalt coating of the balsa trunks was possible for the South Americans.
The Pitch Lake has fascinated explorers and scientists, as well as attracting tourists. Some accounts tell about its rediscovery by Sir Walter Raleigh in 1595. The American Indians knew about and showed it to him to help him caulk his boat. Raleigh himself found immediate use for the asphalt to the task of caulk. He referred to the pitch as "most excellent... It melted not with the sun as the pitch of Norway".
Since its rediscovery, there have been numerous research investigations into the use and chemical composition of this material. There have been countless theories, postulations, and conclusions as to the size, source, and origin of the asphalt:
"The terms asphalt and bitumen is often used interchangeably to mean both natural and manufactured forms of the substance.
Naturally occurring asphalt/bitumen, a type of pitch, is a viscoelastic polymer. However, pitch is considered more solid, while tar is more liquid. Traditionally pitch as was used for waterproofing buckets, barrels and small boats were drawn from pine. Tar is a black mixture of hydrocarbons and free carbon obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. Production and trade of pine-derived tar was a major contributor in the economies of Northern Europe and Colonial America. Its main use was in preserving wooden vessels against rot. The largest user was the Royal Navy. Demand for tar declined with the advent of iron and steel ships."
I myself have met and worked with natural pit-tar in the Andes - found around 4000 meters above sea level.
In Arabia is told, they use goat lard mixed with lime chalk, as protection of their boats against shipworm, but that is too said, that this doesn't work against fouling. But the fouling they easily knock off together with the layer of chalk, where after a new layer is applied. (Passing remark: Such a mix we know very well. When we mix chalk with oil of some sort we get a paste (putty), as we in centuries have used to fasten glass in a window frame - after which the paste get hard and resistant. The Roman engineers used chalk mixed with olive oil to join tubes of earthenware (terracota) for their water supply pipe lines.)
So the question that remain is, if animal grease, venom, poison or other type of extract from plants or animals could have been used for impregnation and protection of their rafts? Or did they at all impregnate?
Heyerdahl in his book: "Seafaring in early Peru" propone a "preparation of gum, resin or vax in some solvent" - - - to protect against the danger of losing buoyancy.
on the old-timer rafts. They used Guaras = daggerboards, and models of Guaras is the only evidence of the Balsas Rafts we have as archeological finds. We have them in shape of models given as grave gifts.
Guaras were made using a hard wood like 'Maclura', 'Tabebuia' or 'Minquartia'. Of other woods as could have been used for Guaras is 'Guayacan', as grow in the territory from Caribbean over Central America and down to the Pacific coast of Colombia and Ecuador. Guayacan is an extreme hard, strong and heavy wood, so heavy that it can't float on water. Guayacan has still today a function in mechanical constructions, but outside it is more known as 'pokenholz' or 'ironwood'.
The word 'Guara' is not a Quechua word - is told to come from a language nearer to Equator, even I personally see the relation to the Spanish word 'Vara' as means stick or pole and seems more as a seamans interpretation. Vara and Guara sounds alike pronounced in Spanish. If there exist a linguistic relation between the names Guara and Guayacan, then it is a task for a professional to investigate, but attention with the spelling of spoken words, Latin letters came to the SouthAmericans with the Spaniards.
As told, the shape of Guara is known from the grave-gifts and that don't need much more archaeological experiments - only in its use, because the size isn't known and neither how many Guaras they needed to control their craft.
What we neither know is how they mounted these Guaras between the balsa trunks. How did they keep the daggerboard in position?
Were they plunged in occasionally in the cracks between the trunks, where they were needed? - or had they a slot with a holder or a sheath to keep them fixed on certain pre-chosen sites?
Simple materials for Hut and Deck
'Caña Brava' or Bamboo we see used on board Balsa raft replicas for different purposes.
There are thousands of Bamboo sorts in Asia, but even today we find only some hundreds in South America. That small number indicate that Bamboo plant may have been imported after the discovery of America, and a question to the biologists could therefor be, if Bamboo in fact had been imported from Asia - and if not: which sorts are natural in South America.
Caña Brava is a type of grass as is rather natural to Mexico, Central America and South America, and that is a grass of own type: Gyneriae - to distinguish from Bamboo.
Researching in the past we don't know which one was common in the local area, but perhaps it isn't important, because if a raft builder needed a simple material for a simple work as a hut, he would take what he used last time, and if isn't exactly by hand, he would take the next.
The message for modern replicas: The ancestors simply imported a little - if anything - because long distance transport was extremely difficult. So nothing was imported from China and neither sisal, hemp nor manila (an attitude in serious contrast to today).
we have got no finds of those fittings from pre-columbian time
Gear and materials for rigging
Naval Rigging gear
The incas didn't know the advantage of wheels,
but if we therefor can conclude, that they didn't know anything, as could rotate, I am not sure. My conclusion is that they didn't employ neither sheaves nor blocks in their rigging, because they didn't have any metal axle to use for block nor sheave. That is at least, what I think for the moment.
Nevertheless every sailor know, that a mast need a good guided turn-around for the halyard in the top of the mast. That is the only way to hoist a heavy sail.
Therefor they have to let their halyard pass over some stationary rounded piece that could be of wood - but we can't reject other materials as horn, bone, ceramic or seashell - at least something with low friction and resistant to wear. In the european cultures we sometimes have had a wooden eye in top of the mast, to heave up a smaller sail, and we know several fixed eyes as of shown type.
collection of wooden eyes without any rotating partthat could be - but nothing is found
As user of ropes we know, that a twined = 2-strand-twisted rope is very knotty to use in a running rig, at least hauling over a guiding wheel or an edge.
The SouthAmericans use twined ropes on their small reed-rafts on Lake Titicaca. On bigger vessels hauling over a rounded pole or through a wooden eye a 2-strand rope would not be very appropriate, and a braided is to prefer. As supplement a braided rope neither twist over a shear in dependance of the tractive force - when lifting the sail versus lowering. That does a halyard of twisted rope.
a guidance created by the naturedon't forget that the Inca's ropes probably were braided
If no sheaves nor blocks were at disposal then for halyard, an alternative to a polished hardwood eye in the mast top could be something manufactured out of a sea conch. The inner thread of a sea conch seems shaped as a useful raw material for a guided turn-around for a halyard rope in the top of a A-mast - or perhaps something other could be made of ceramic material. But still pure speculation and nothing proved.
Mast top design based on a Pacific Samoa catamaran has resolved this rigging problem as shown - without any wheel based block, but natural spars and handcarved deadeyeblocks There is used a gaff in top of mast and not a sheave - to turn the halyard over (Ref. Wharram Amatasi - a 27' ethnic design)
The only information we have around ropes, are some notes from the early Spaniards, saying that the South Americans in Manta had a production-place for fabrication of cordage and rigging of Henequen, (what as explained probably was another local plant material). Production plant means but a site where the men could work with bigger things - that doesn't say anything around how the worked nor what tool they employed. I could imagine a large square ground, with space for many working people where they could spread out their canvas for cutting and sewing the sails - and too with space to make their ropes.
there are a heavy tradition in the zone for work with those things
Fibers and yarns
In all cultures things as yarn, knots, sewing and ropemaking were some of the first steps on their way of development. They joined things with a yarn - whatever the yarn material was vegetal fibers, strings of hide, sinew or intestines from animals. Therefor yarn and knots are among the oldest archaeological finds. Even the first build boats were bound and sewn together, whatever they were made of hides, bark, planks or reeds.
The South American cultures were all very keen in textile works, that is verified in remanent textile finds from the Paracas culture until the Incas, and their hundreds of suspension rope-supported bridges all over their land confirm this competence.
Natural fibres all hold a limited length. Therefor we join fibres and interlock them by a spinning process and get a yarn.
That we do, to let the friction between the fibres make it difficult to slide them apart by just a pull in the yarn - and then to prevent their tendency to untwist, we twine two or twist three of these yarns together in a cord.
In some cases we are able to make the spinning and the twinning in one-only process as they do on the Qeswa-chaka. There they excercise the double process of spinning and twinning between two palms or between a palm and a thigh. For their reed rafts on lake Titicaca they too do it in same way.
But not all fibres are possible to spin. The Sarhua-chaka is an example, where the short and rather rigid "fibre" is wicker-vine or flexible rod, as they only can interlock by a braiding - a 3-braid, because a spinning will not have force to keep them together.
The favour of twining and braiding versus freeflowing fibres is known by each long haired man or woman since the viking-era, setting up their hairstyle and sometimes their beard.
But very few are twisting their hair by 3 strands as a rope on a ropewalk, because that needs more than two hands. They braided their hair.
The introduction of the ropewalk gave an advantage in ropemaking - longer ropes, quicker and better process - the same the textile workers experienced, when they turned their craft from needelbinding to knitting now using more sticks (and no needle) and long continous yarns.
Post note: Modern artificial fibres can be produced in infinite length, and therefor don't have the need to be spun together to keep a tensile strength. A modern rope could be made of a parallel multifilament core kept together by an braided/woven exterior jacket, mantle sheath or what you call it in your culture.
Sails and canvas
Plain canvas weaving
Image Explanation: This is a fill-oriented weaving, in which the warp fibers (running from the upper left to the lower right) are woven over and under the straight fill yarns. In this construction, all of the crimp is in the warp and a stretch in the fill direction is minimized.
Titicaca sail of totora reed
And that is more or less the same they do, when making sails of totora reed on lake Titicaca - with the exceptions as seen on the photo: - the warp is made of twined reed - the warp is interlaced by a twinning (today they in general thy use cloth canvas up there)
Sails of Cotton are obvious for the old timers, and we don't know any real alternatives in South America, because wool from sheep didn't exist and wool of llamas probably wasn't the best for sails. Cotton is native too the continents of America, Africa and Asia but came late to Europa. In Europa they used other fibers for the sails as flax - or wool from sheep. Later on came Hemp and then at last Cotton. The weaving of canvas = heavy cloth for sail - how did they in Manta? - what could they? - which type of weaves was employed for the fabrics? and which technology was at disposal for the sail fabrication?
We know from other regions that there are - what is referred to today as: Two-shaft or plain weave (one thread over and under one thread), Three-shaft or 2/1 twill (two threads over and under one thread) and Four-shaft or 2/2 twill (two threads over and under two threads).
Nevertheless these sophisticated weavings, I have no knowledge around, what the South Americans used for sails; but the scholars opine, that the South Americans had used plain weave, because there was no reason for other.
Guaman Poma drawings - 400 years ago
Backstrap looms were in use from before arrival of the Spainards - even narrow, the backstrap loom is usefull for production of long lengths, as claimed for sewing of sails -
women still use the backstrap loom on Taquile island, Titicaca, Peru
In Inca-land are still preserved remains from their many suspension bridges
No old-timer-raft re-constructor has in newer time spent much effort to understand and face "the rope dilemma", and they use happily whatever, as Hemp, Manila or Sisal from China - but strange to say, not Henequen as is named by the old Spaniards. We could provocatively ask new raft-builders: Why import twisted sisal ropes from China, if neither Sisal nor twist of 3-strands was original in South America?
The South Americans didn't use ropes neither of Sisal (Agave Sisalana) nor of Henequen (Agave Fourcroydes) even if the first chroniclers say so. Henequen was natural from Yucatan and therefor known by the Spaniards, coming down from the conquest in North to carry on with their profession in South, and of that reason they identified the ropes on the balsa rafts as Henequén. Later on after the arrival of the Spaniards the fiber Henequen generally was replaced by Sisal. Because of this Spanish bewilderment and misunderstanding every experimental adventurer or scholars reading the old Spanish accounts is today talking only Sisal.
Logistically we too can feel much doubt, if the Inca-populations really had transported Henequen all the thousands of kilometers down from Yucatan to employ ropes of Henequen for their ocean sailing balsa rafts - and in no way Sisal, as didn't exist at that time.
In S.America : Nothing of Sisal, Henequen, Hemp nor Manila - they had other fibres
It is more probable that they in the same way, as by construction of their suspension bridges all over their incredible land, have made use of local grown raw material - and they have several natural plant fibers. That could be fibre of a native agave-plant as Cabuya Blanca or Marguey, Fique or Penca (Furcraea Andina) as grow in Peru and Ecuador in up to 2000 meters over sea level or it could be Cabuya Azul as grow in altitude up to 3000 meters. This last is still today used as a building material.
The descendants of the Incas living in the valleys still use those many plant fibers. For example are rafts and purlins (roof timbers) on countryside houses still tied by cords of plant fiber or thongs of hide (as in every ancient civilization) and not jointed by nails.
Ropes braided by thongs of hide or leather isn't a bad idea. It could perhaps be a good thing to consult some of the still active ropewalks in the valleys of the Andes to learn which local fibre more than Cabuya Blanca could be useful for ropes. Cotton I have never heard used for naval ropes. I don't know why.
The suspension bridges are the best evidences of ropemaking in the S.American cultures, and even today two bridges has survived - or better to emphasize, that in spite of all modernizations, two bridges have survived the elapse of 500 years since the collapse of the Inca Empire - due to their particular maintenance system. The Inca had charged the nearest villages to maintain and renew their bridge - and that they have done since as a yearly collective task. (I am not aware, if any other maintenance system from the old world has been able to work uninterrupted in such a span of years).
Qeswa-chaka (Chaka is a Quechua word as means 'bridge') has been maintained half a millenium at least (we don't know in which year it was build first time) without interruption - handling over the experience and knowledge from generation to generation.
Sarhua-chaka has had an interruption in nearly one generation, but has taken up the common task again before the know-how was lost.
PukaYaku-chaka was abandoned and lost many generations ago - but 2006 there has been a lonely archaeological reconstruction by initiative of INC-Instituto Nacional de Cultura, Ancash, Peru.
Not handmade - Each time we find a rope twisted of 3 strands or more, we can be nearly 100% sure, it is produced on a ropewalk
Twisted of two, three or four strands - or braided
Nobody knows with certainty how they made ship-ropes in "Inca-land", because nothing is found from oldtimer rafts.
In the circles of balsa raft replications we have never heard any discussion around what type of technology was employed by the South American ropes. Of course it is possible to put in one or two more strands into a twinned and make three- and even four-strands ropes without ropewalk, but that is a harder labor and without visible cause. Why should the Incas make three-strand twisted ropes when braided could do it?
Verified by what we find in textiles: What we too see on the two last surviving suspension bridges, is that ropes are twisted with two strands or braided by three or more.
You can easily pass Qeswa Chaca by foot, and study the suspension bridges, which is still maintained 500 years after the Inca empire collapsed. It seems as 3-strand braided mostly was used for heavy duty and twisted 2-strands for the lighter use.
But in reality the problem by bridge-building probably was more concentrated around: how many bunches (two or three strands) was needed to give strength enough. The number gave then the construction - twisted by two or braided by three.
In all cases, this two rope constructions: twinned 2-strandeds and 3-braided are the most simple way to produce hand made ropes without a rope walk.
- or said the other way around: To make a 3-stranded twisted rope by hands only is a clumsy way to work.
twined is the only way to lock two cords or yarns
3-strand twisted need more hands - or a ropewalk
a third cord applied - in a second passing
3-braided = the only way to braid three together
the most famous and only surviving inca bridge
Qeswa Chaka - the bridge of grass
the last Inca Bridge: Qeswa Chaka - outside Cusco
A close-up photo of the braided rope. We see the braiding, and we see that the bunch is made of twinned yarns of grass
The last surviving suspension bridge near Cusco has been maintained 500 years without interruption - and is still renewed each year.
An unique system of maintenance dictated by the Inca.
Note the heavy braided rope as is for support of the footpath. The material is ichu grass.
Qeswa Chaka means 'the bridge of grass' - in Quechua: chaka=bridge and qeswa=grass - and the bridge is crossing Apurimac river south east of Cusco in Perú.
The ropes are made by ichu-grass as is the most common grass in that area. First they produce the "twinned yarn". The grass is twisted between two palms - or one palm and a thigh + and is twinned in one process: Twist >>> change grip >>> and twist again. That technology can be studied in details on many videos as this, uploaded on the Internet.
Next process is bunch and strand. 25 twinned yarns are stretched out in 40 meters - then kept together in a bunch and twisted by hand between two teams.
Then for the handrope the third process is to twine two of these strands, so they will lock together and eliminate the build-in torsion. A twinning is the only possibility to join two-only cords - there don't exist other solution, so that is what they are doing.
The main ropes, as serve as support the footpath, will be made by 3 of these strands. To join three twisted strands exist theoretically two ways to do it: you can twist or you can braid. The Incas 3-braided. Why braided?
I suppose that it will be very difficult to obtain a homogeneous result of a twisting process, working with 4 teams on a 3-strands rope in length of 40 meters without suspend it in fixed suspensions as on a ropewalk. A braid-process is self-locking and therefor to prefer.
I don't know if the Incas knew the process of three-stranding. Probably they did, because they were very keen to fibre handling - but said with plain words: I myself wouldn't like to be the responsible team-manager on such a strand-job. Too complicated.
The raw-material is Ichu-grass - the harwest of ichu - break the stilk
spinning and twinning of "yarn" in one process
first lay out 25 x 40 meter of yarn on their "ropewalk" before twisting
two teams - one in each end - for twist of the 25 "yarns" to one strand
supervision of twinning process
stretching out the twinned "handrail"
a braiding is without tension between strands
transport of the braided cables
the peasants workmen
The finished suspension bridge
Until now has surviwed know how around this suspension bridge
Sarhua Suspension bridgeRaw-material of withy rods - therefor another technology
The Sarhua suspension bridge Tinkuq Chaka as in Quechua means 'the bridge over Tinku' - in Ayacucho, Peru is technically rather interesting. They don't twist anything!
First they harvest the raw material as is a local long-vined wicker.
Finger-thick wickers cannot be locked together by a twist-process, therefor the "fibers" are interlocked in a "yarn" as a 3-braided wickerwork.
Next step is to braid 5 of these 3-braids in a final 5-strand braid as will support the footpath. That is done as an impressive joint teamwork, or rather by two teams, braiding each their half of the 'main' - the two teams of social reasons come from each side of the river explained on the photos.
That is the Inca way to make ropes - as instructed more than 500 years ago.
A 5-strand braid can be made in several ways - but which one is employed by the Sarahuans is not quite clear.
Raw material: withy-rods of 2-3 meters
locking those rods together in a "yarn" by a 3-braid
This first 3-braid is called Aqara
A teamwork as will employ all hands
fastenings on shore
Considerations over 5-strand braided
To twist a rope is only a special way of braid - but much easier to make on a ropewalk
An analyze of plain 5-braid-technology of symmetrical reasons show 6 combinations. One of the outermost cords (left or right as you will) has to pass 4 others, and those four we can "count" or combine in the 6 different ways - and compared with the notation as we use by twill weaving O=Over and u=under:
Over - under - Over - under
O - u - u - O
O - O - u - u
O - O - u - O
O - O - O - u
O - O - O - O (as is the same as a twisted rope)
Which one of the 6 options for 5-braiding was used for Sarhua suspension bridge isn't quite known, but the photo seems to indicate the SYMMETRICALs braiding with the notation: '22 = OOuu' - as too is rather simple to command to the braiding teams.
notation 22 = Over-Over-under-under as seems to be the used at Sarhua
notation 1111 = Over-under-Over-under = the most common of 5-braidings
It feels rather confusing, but the photos from the last re-creation 2014 in Sarhua seems not to show 5-strand braided ropes as the 1977 photos did - they now seems to make 4-strand braided ropes ? but difficult to observe - try yourself
Pukayaky bridge is nearly forgotten
Pukayaku bridge over Yanamayo river in Ancash
There were hundreds of bridges all over Inca-land, when the Spaniards came. The bridge over Yanamayo river was abandoned around the time of the creation of the creole republic, but it has recently been reconstructed as an archaeological experiment under sponsorship of INC - dirección Regional del Cultura, Ancash 2006.
The technical facts were very scarce: Span of bridge 45 meters - and an all together consume of 30 kilometers "sogas trenzados" of 1 cm in diameter. The four mains are seen 3-braided.
The type of fibre wasn't known from the historical accounts - only that the bridge was build of some type of vegetal fibers.
They chosed fibre from Agave Americana, Marguey, Carbuya, Penca Azul - what more or less are synomym names for the same. There are registered around 200 types of American Agaves.
The interesting point for ropemakers is the use of fibers from the agave Penca Azul, whereas the technology employed for ropemaking seems more questionable around autenticity. They say for example that they had "trenzado las sogas" what directly means that they have "braided" their cords - but to our confusion the near-photo shows that they are twisted - and not braided.
This rise much doubt, because it is difficult to verify, but it seems as those "yarns" are of 3-strands, and that at least indicates that a ropewalk had been employed. (what we understand very well for a production of 30 kilometers).
On the other hand the main ropes are shown 3-braided of bunch-twisted cords, what indicates they are handmade - without use of any ropewalk - but very nice craftsmanship.
The agave Penca Azul - with a wat of extracted fibre ready to be spun
photos from INC-Ancash
Rope technology for Totora reed raft
Fermin can add fibres (grass) under the braiding process
the reed hull ligated by 3-braided
the twining too permit fibres added under the twist-process
All running rigging together with sail is made by twined straw
Beside the lore of suspension bridges and their cables we still have the construction of reed rafts on lake Titicaca.
For the construction of their totora-reed-raft the Aymaras - Paulino Esteban, Thor Heyerdahl's reed raft builder - used a 3-braided rope for tying the hull - and a twined ropes for construction of all rigging inclusive sewing of the totora sail.
The raw material is Chilliwa grass from their highland.
Both the twinning and the 3-braiding technology permitted them to produce long length of both rope constructions feeding-in straw - all in one-only process
More detail around the totora-reed-raft produced can be forund on page #2
Native ropes in the Andes
On contryside in the Andes mountains - the farmers still produce ropes of hair of own animals for own use - in general made of Llama hair, but too from sheeps and alpacas. Still traditionally braided - and if twisted then never with more than two strands. Twinning! Owing to tradition or missing ropewalk ?
That activity we expect will disappear, when television enter in the valleys to ocupy people to passivity in the evening - as we have seen in so many other places.
8 strand square plait from the mountains
square 8 strand braid crafted as the native
In Peru I have seen round 32-strand - used on a sling - but that was impossible to investigate how it was made
Stranded ropes are still used onboard modern ships. 8 strand plaited mooring rope is a rather common type - sometimes called multiplait, octoplait, round braid or diamond braid. The shown model of '8 strand plaited' mooring rope hold a little disingenuous name, because that is in fact a 4-strand plait, made of double cord, because braided with pair of strands, the mooring rope becomes more round and smooth.
mooring rope made by double - respective single cord4-strand = as is a 2-ply-S interlaced with a 2-ply-Z.
the rope industry and its technology
The anachronistic Ropewalk
In South America wasn't any Ropewalks before the Spaniards introduced them
Fibres spun into YARN yarn bunched and twisted into STRAND strands twisted or braided into ROPE
Each twist process normally change between S- and Z-strand to make a torsion-free rope
A Ropewalk is a wonderful tool, but it entered late in our naval development, as it came to Europa in the Middle Ages from the great cultures in Asia, where it has dwelled hundreds of years.
From then it is taken for granted, that naval ropes are three- or four-strands and made on ropewalk. That is a so established interpretation, that even museums and replica-builders in Europa without shame use this anachronistic ropewalk-technology in their oldtimer exhibitions from the time before Middle Age, ignoring that ropewalks was taken in use only a few hundred years before Columbus left for America.
From Europa it passed over the Ocean to America where it arrived together with the conquerors.
A Ropewalk the South Americans never knew
The ropewalk came late into the European development - first by Mediterranean and some hundreds of years later into North
1 step: stretching out the yarns
2 step: bunch+twist of strands
3 step: twisting the rope
3-strands ropes had probably been known from old time as a short-length ware.
Until the ropewalk our rope work was made by hands of men, which make the length of ropes limited to what they could handle with their hands and carry in their arms.
In the process of stranding 3 cords to a heavy rope it is very difficult to twist by hands, keep twisted - and synchronous feed long length of cords into the process and haul the strand rope out. That need a rather numerous and experienced team. Whereas a braided rope only need a minor team, because the process is self locking.
Ropewalk with really heavy rope
Technology leap: In the same period of time the knitwear-making changed from naal-binding: sewing with needle and short length yarns (2-3 meter) - to knitting: interlacing stitches on long yarns. (Naalbinding >>> knitting)
The ropewalk gave the option to stretch out the material in full length, while twisting more cords together in a rational process. We could now produce ropes until the length of the same ropewalk, what could be some hundred of meters. If we wanted longer ropes we had to splice two ropes together or prolonge our ropewalk.
It is limited so, simply because a classic ropewalk doesn't have any machinery to accumulate the rope after the process - no bobbin nor spool.
Those spool machinery came together with the industrialized processes as the consequence of production of steel- and electrical cables in the mid of 19 century. In the same time the rope-production for sail ships waned out. Of logical reasons the masters and workers in this new cable factories were recruited from the navy together with their technology, and from then, the machinery for ropes and electric cables followed the same line of development.
The long ropewalks disappeared and the spool machinery came in with their "pay off" from spools to feed the process and a "take up" the rope on a bobbin after - reducing a process line from some hundred meters to around 20 meters - and in the same time lengthening the produced cable to what could be hold within a bobbin.
Modern rope machinery work with two principles
Rotating take-up spool + 3x rotating pay-offs as are turning syncronizedAdvantage: Supposed to produce fastest, due to the mass of the rotating parts is closest to their axes and therefor permit more RPM, as give us more twist per minute The negative is a limited size of the take-up bobbin
Stationary take-up spool + 3x pay-off spools rotating in orbit - each pay-off giving contra-turnAdvantage: A big stationary take-up as can receive cable from more pay-off spools changed out and spliced in prolongation
Allegation: A same great revolution, as the change from handling and delivery of ropes in coils to handling of bobbins, was more or less repeated hundred of years later with introduction of containers for rational packing and transport of general cargo.
Conclusion on the rope discussion
Historically the ropewalk moved the produced volumen from hand made braided to twisted machine made
modern industrial version, of what could be a braided Inca-rope
Now the machines offer production of braided ropes - or with wowen jacket