Sunday, September 16, 2018

Log Rafts on Ecuador’s Rio Napo

While investigating logboats in the Rio Napo drainage in Ecuador in June, I observed six log rafts within a few kilometers of each other – and no others elsewhere in the same drainage. I do not know if this clustering of rafts was particular to a limited area or if further investigation would reveal more widespread usage.  

According to my guide and one other informant – a woman on a raft with her children on the Rio Arajuno, a tributary of the Napo – the rafts serve four or five functions. When observed, the woman's raft was tied to the shore and she was using it as a stationary platform on which to do her family’s laundry, the river bank near her home being too steep and muddy to allow her to do it directly on the shore. She indicated that she also uses rafts to cross the river (the reason for which is unclear) and to deliver her farm’s produce downstream to the nearest road crossing, where it is picked up by a truck for transport and sale in the nearest market town. The downstream trip with produce is a one-way excursion, there being no practical method to bring the raft back upstream. At least some of the time, therefore, the raft itself may be sold for its logs at the end of the voyage. According to my guide, rafts are also built by some of the numerous "jungle lodges" in the area to give tourists the experience of rafting in the Amazon basin  quite a different experience, by the way, from the whitewater rafting that is popular in the foothills of the nearby Andes in inflatable rafts.

All the rafts observed exhibited strong similarities in their basic construction. Their main logs were all bound together by two crossbeams locked in place by pegs driven obliquely into the tops of the main logs, and the crossbeams were lashed to the pegs. All had at least some of their main logs cut to a point in plan view at the (presumed) bow end for hydrodynamic efficiency. According to my guide, the main logs are typically balsa wood, although to my untutored view, they did not all appear to be of the same wood. I observed a push-pole on one of the rafts and presume this is the common method of propulsion, no paddles or other propulsive devices being seen. 

Beyond these similarities, though, the rafts exhibited distinctive differences that seem to indicate that the technology, while useful and surely rooted in tradition, is not rigidly bound by it. For example: the rafts were built of 3, 4, 5 or 6 logs – quite a range of variation in just six examples; some of the rafts had additional crossbeams above the crossed locking pegs    others did not; some of the pegs and crossbeams were milled lumber    others were not; and the lashing materials varied widely. The photos and captions below explore these similarities and differences in designs and construction. 

log raft, Amazon Basin, Ecuador
The most archetypal of the six rafts has five logs, pointed at the bow end (left of photo) with two sets of cross-beams. (Click any image to enlarge.)
log raft, Amazon Basin, Ecuador
Each set of cross-beams consists of two beams, one atop the other, held in place and separated by pairs of pegs driven into the main logs in an X pattern. The beams and pegs are lashed together with what appear to be narrow palm leaves (possibly pandanus?).
log raft, Amazon Basin, Ecuador
The upper crossbeam is lashed indirectly to the lower one, and not to the pegs. Its purpose may be to spread the upper legs of the X'd pegs, locking them into the main logs.

log raft, Amazon Basin, Ecuador
Just forward of the forward crossbeam assembly is a pair of crossed pegs set in the top in the middle log. Their purpose is unknown: perhaps they were placed incorrectly and could not be easily removed.
family on log raft, Amazon Basin, Ecuador
The informant doing laundry with her children on a six-log raft. Most of the logs are tapered in plan view at the front. The boy wearing red shorts is sitting on a bench whose legs extend between the logs. The bench is not fastened to the raft and probably does not represent a permanent part of its furniture. 
log raft, Amazon Basin, Ecuador
Lashing and peg arrangement of the forward cross-beam assembly. The lower crossbeam appears to be let into the upper surface of the outboard log.
log raft, Amazon Basin, Ecuador
The cross-plank in front of the woman is nailed in to least one of the logs. It is unclear if the plank she is sitting on is fastened or loose. The lower aft crossbeam also appears to be let into the upper surface of the outboard main log. 
log raft, Amazon Basin, Ecuador
Unlike the previous rafts, the main logs on this 3-log raft are spaced away from each other, not adjacent. The outer logs are much larger in diameter than the central one and their bow ends are tapered both in plan view and from the bottom to the top for a true boat-bow shape. The smaller central log is only slightly tapered in plan view. 
log raft, Amazon Basin, Ecuador
The front crossbeam is a single beam. On the port log, it is secured by a single peg placed aft of it.
log raft, Amazon Basin, Ecuador
The aft crossbeam assembly consists of two crossbeams, the upper one being a piece of recycled milled lumber. The port (foreground) lashing is old fishnet. The starboard lashing is a piece of insulated electrical wire. There are no lashings at the middle log. Forward of this assembly (to the left) is a piece of milled lumber nailed into all three logs and serving as an additional crossbeam.
log raft, Amazon Basin, Ecuador
This four-log raft was found aground on a gravel bar in the middle of the Rio Napo, probably washed from its owner's shore front home by heavy rains a couple days previously. The logs are all adjacent, the outer ones being much larger in diameter than the inner ones and milled flat on their upper surfaces. The inner logs, however, extend somewhat further (but not equally so) than the outer ones. The ends of the outer logs are boat-shaped; the ends of the inner logs are square.
log raft, Amazon Basin, Ecuador
At the opposite end, however, one of the inner logs is tapered to a boat shape while the other remains square. Both outer logs have notches cut in the upper edges of their tapered sections, probably to hold ropes which are no longer in evidence. Perhaps the logs were previously used in another raft which was held together by lashing alone instead of the pegs-and-lashing method.
log raft, Amazon Basin, Ecuador
Next to one of the crossbeam assemblies are a pair of vertical rods that stick up more than half a meter from the upper surface of the outer logs. Their purpose is unknown. The crossbeam is a single piece of milled lumber
log raft, Amazon Basin, Ecuador
The other crossbeam, also a single piece of milled lumber (but of different dimensions) is lashed carelessly with old fishnet. One of the pairs of pegs in an outer log (left foreground) does not enclose the crossbeam, providing support to the notion that the outer logs previously belonged to a different raft.
End view of the same raft shows that the smaller, inner logs are set lower than the larger outer ones.


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