Inca's Balsa Log Raft
Natural local materials and technology
Around the Natural base for south American seafaring
Influence from handling and the execution of other arts of Work
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 was 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 way these handicrafts had their influence on the creation and construction of Balsa rafts. That we still don't know much about.
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.
Wooden materials for rafts
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 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 ware 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.
Mangle Wood,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 a good idea - because balsa traverses at least offer extra buoyancy, if the main trunks go down
As said: How the south americans cut down their trees and worked the material, that we still don't know.
Wood for Masts
An A-mast seems a common equipment to a Balsa raftAn 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. Omly 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 came 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.
Tar we use in Europafor 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.
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, that 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 - in around 4000 meters above sea level.
In Arabia is told, they use goat lard mixed with lime chalk, as protection against shipworm, but that 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? 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.
Guara, the mystical Inca Rudder
A rudder was absenton 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 - seems to come from a language nearer to Equator. 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 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 could 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 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).
Materials for Rigging
Sails of Cotton are obvious, 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 Africa, Asia and America 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 Manteño? - 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). But by the Incas - I haven't any idea what they did.
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.
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. Nevertheless 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. Therefor they have to let their haylyard pass over some stationary rounded pole or through a wooden eye in top of the mast, to heave up their sail, and that could be a fixed eye of shown type.
As user of ropes we know, that a twined = 2-stranded 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-stranded 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 on a stranded rope.
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 could be a shaped raw material for a useful turn-around and guiding for a halyard rope in the top of a A-mast. But still pure theory and nothing proved.
The only information we have around ropes, are some notes from the early Spaniards, saying that the South Americans in Manteña 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.
Fibers and yarns
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.
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.
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 3-braiding, because a spinning will not 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 braid 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.
Ropemaking in the time of the Incas
Ropes from inca-constructions:
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 stranded sisal ropes from China, if neither Sisal nor strand 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, 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 on their ocean sailing balsa rafts - and in no way Sisal, as didn't exist at that time.
Nothing of Sisal, Henequen, Hemp nor Manila
The descendants of the Incas living in the valleys still use those many plant fibers. For example are rafts and purlins (roof timbers) on houses still tied by cords of plant fiber or 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 rope-walks 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.
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 mantenance system. The Inca had charged the nearest villages to maintain and renew their bridge - and that they have done since as a collective task. (I am not aware that any other maintenance system has been able to work 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-chakahas had an interruption in nearly one generation, but has taken up the common task again before the know-how was lost.
PukaYaku-chakawas 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.
Rope-technology and rope-making
Two-, three- or four stranded - or braided? Nobody knows with certainty what they did 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 four-stranded ropes without ropewalk, but that is a harder labor and without cause. Why should the Incas make three-stranded ropes when braided could do it?
What we see on the two last surviving suspension bridges - verified in what we find in textiles - is that ropes are made with two strands or braided by three or more. Studying the suspension bridges, which is still maintained 500 years after the Inca empire collapsed, it seems as 3-braided mostly was used for heavy duty and 2-stranded for the lighter use.
But the reality for the problem by bridge-building was probably 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: 2-strandeded 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 rope by hands only is a clumsy way to work.
- in a second passing
Qeswa Chaka - the bridge of grass
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
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.
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 + is twinned in one process: Twist >>> change grip >>> and twist again. That technology can be studied in details on many videos as this, found in 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 3 of these bunchs. To join three twisted bunches exist theoretically two ways to do it: strand or 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-stranded rope in length of 40 meters without suspend it in fixed suspensions as on a rope-walk. 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 task-mannager on such a strand-job. Too complicated.
Sarhua Suspension bridge
Raw-material of withy rods - therefor another technologyThe Sarhua suspension bridge Tinkuq Chaka as in Quechua means 'the bridge over Tinku' - in Ayacucho, Peru is technically rather interesting. They don't strand 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 join 5 of these 3-braids in a final 5-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-braid can be made in several ways - but which one is employed by the Sarahuans is not quite clear.
Some variants of 5-braidingAn 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:
|1111 =||Over - under - Over - under|
|121 =||O - u - u - O|
|22 =||O - O - u - u|
|211 =||O - O - u - O|
|31 =||O - O - O - u|
|4 =||O - O - O - O (as is the same as a stranded rope)|
The notation: Over-Over-Over-Over signify a 5-STRAND, as not will be very form-stable without a filler in the middle
Which one of the 6 options for 5-braiding was used for Sarhua suspension bridge isn't known, but my guess is one of the SYMMETRICALs - with notation: '22 = OOuu' or '121 = OuuO' - being rather simple to command the braiding teams.
- they now seems to make 4-braided ropes
Pukayaku bridge over Yanamayo river in AncashThere 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 ropemakersis the use of fibers from the agave Penca Azul, whereas the technology employed for ropemaking seems more questionable around autenti city. They say for example that they had "trenzado las sogas" what directly means that they have "braided" their cords - but to our confusion the photo shows that they are stranded.
This rise so much doubt, because it is difficult to verify, but it seems as those "yarns" are 3-stranded, and that 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.
- with a wat of extracted fibre ready to be spun
Rope technology for Totora reed raft
Beside the lore of suspension bridges and their cables we 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
The anachronistic Ropewalk
yarn bunched and twisted into STRAND
strands twisted or plaited into ROPE
From then it is taken for granted, that naval ropes are three- or four-stranded and made on ropewalk. That is a so established interpretation, that even museums and replica-builders in Europa without shame use this anachronistic rope-walk-technology in their oldtimer exhibitions from the time before Middle Age, ignoring that rope-walks was invented 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.
3-stranded 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.
- to knitting: interlacing stitches on long yarns. (Naalbinding >>> knitting)
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 stranded 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.
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 mostly came as the consequence of production of steel- and electrical cables in the mid of 19 century. Of logical reasons the masters and workers in this new cable factories were recruited from the navy rope-walks 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
as are turning syncronized
The negative is a limited size of the take-up bobbin
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.