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Saturday, February 25, 2012

Dugouts 8000 Years, 7000 Miles Apart

There's really no connection between these two stories, aside from the fact that they're both about dugouts.

Chinese Dugout, 8000 BP

First, we have one of the oldest dugout canoes ever discovered, at Kuahuqiao in south China. Dated to 8000 years BP (before present), it's firmly in the Neolithic period, coeval with the early domestication of animals and the earliest instances of agriculture. While far from complete, the canoe and related artifacts present intriguing glimpses into this extremely early example of timber boatbuilding.

Construction of the pine hull was probably done with a combination of stone adzes, which were found at the site, and fire, examples of charring being detected on the hull. Also found was piece of woven matting attached to frame of light timbers -- very likely a square sail and spars. It has been suggested that smaller timbers found near the hull might have been part of an outrigger assembly, but the upper parts of the hull, where outrigger booms would have been attached, are missing. So what was probably a sailing canoe might or might not have been supported by an outrigger.

Three paddles were found in the assemblage, two of them apparently unused and placed carefully beside the canoe. This would appear to be in keeping with the notion of a ritual interment, but the absence of other ritual items beside the hull makes this notion difficult to support.

Among remains of several game species at the site were those of dolphin, probably indicative that the people who built the canoe used it to hunt at sea.

Finland Dugout, 1936

Here's a great video with much to teach about expanded-and-extended dugout construction in the modern era. The canoes were used to gather marsh grass, presumably for fodder.



Items to notice:
  • Primary tools: axe, adze, hand-plane (often used by two men at once)
  • When hewing the sides, the workers tap them to test for thickness, apparently relying on the sound or feel of the wood as it's struck.
  • The interior of the hull is tarred, and the ends are bound with withies, before the process of expanding (spreading) the hull begins.
  • The hull is heated first over an open flame, then hot rocks are piled inside. The exterior is swabbed down with a mop, probably to prevent charring on the exterior, and also to prevent splitting.
  • At least nine frames are hewed partially to shape, then fitted to the hull, with some adjustment to the frames and some additional spreading of the hull.
  • The outer edge of the sheer is tarred, then caulking is stuck to it before the additional strake is added.
  • The top strake is mostly cut to shape, then bent on apparently cold, its shape being adjusted as needed.
  • When being paddled solo, the paddler sits in the bottom far in the stern, using a double-bladed paddle. The bow rises high out of the water.
  • One man would manage the canoe while another walked through the marsh gathering the grass. Note the latter's use of something very much like snowshoes to prevent sinking into the muddy bottom.
  • With the canoe weighted with a huge load of wet grass, paddling gives way to poling.

4 comments:

  1. Interesting that the Finnish logboat builders tapped the sides to deduce thickness. I have always wondered about the boring of holes and the insertion of wooden pegs in order to decide when the correct thickness was reached.

    While this was done very early, trenails using the same process are not accepted as coming into use until the Iron Age. Given the carpentry skills displayed even in the Mesolithic one has to wonder about this position.

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  2. Edwin - I agree that the trunnel is so much easier and quicker to use than the mortise-and-tenon fastening method used by the Bronze Age Greeks, that one would expect it to appear earlier in the record. However, the trunnel seems to imply frame-first construction, with relatively heavy frames, and this didn't occur until relatively late. The method through the Bronze Age was still shell-first construction, with frames added later for stiffening but not as primary structure.

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  3. I take the point Bob as trenails into frames through planks are going to be much more secure than trying to use them to fasten plank to plank. Thinking about it, until they deteriorate, stitches do provide a positiv hold. Interestingly the thwarts on the half-size ferriby boat reconstruction do seem to be held on by pegs.
    http://www.bbc.co.uk/ahistoryoftheworld/objects/o3jMHkrlTPiQCNd3TYy8EA

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  4. I listened to the sound track of the video. The name of these boats is haapio. That name comes from haapa, which is the name of the tree that the boat was made of (aspen). They used also term haaparuuhi (aspen punt).

    The soundtrack did not mention that the stones would have been hot. It said that the stones were used to improve the shape where it was not perfect after the heating and spreading process. They said that the wood is at its softest when the tar inside boils.

    They mentioned another alternative method of spreading the hull. The boat could be sunk in warm water (a warm bay). First steps in spreading the boat could be taken after 24 hours. The whole process would take several days with this method.

    They said that in addition to fishing the boat was used for making hay. They also mentioned hunting (in the wilderness) as a traditional use case. The boat was light, so it was easy to carry it from one small stream to another. They said that a skilled hunter could even make a boat (in the wilderness) for himself if needed.

    Thanks for the wonderful blog,
    Juho

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