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.
|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.)
|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.
|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.
|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.
|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.
|The front crossbeam is a single beam. On the port log, it is secured by a single peg placed aft of it.
|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
|End view of the same raft shows that the smaller, inner logs are set lower than the larger outer ones.