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Tuesday, September 14, 2010

Basket Boats Worlds and Ages Apart

Woven or "basket" boats are among the less common and lesser-known types of indigenous boats. (I believe I've mentioned them only once since I began blogging more than two and a half years ago.) But woven boats have certain advantages over dugouts, skin-covered frame-built boats, bark boats, rafts and floats, which makes their apparent scarcity surprising.

Woven boats go back a long time. The Mesopotamians certainly had reed rafts and floats but, according to Paul Johnstone, "The availability of bitumen enabled the boat-builders of the Tigris and Euphrates to overcome one of the chief defects of the reed craft, the short-lived nature of its buoyancy." It seems likely that reed rafts were initially coated with bitumen as a preservative, but eventually it probably became clear that "a reed framework covered with bitumen produced a combination of a flexible shape and a smooth featureless exterior without lashings, sewing, planks, or cross-beam ends."

Silver boat model from Ur depicting a bitumen-covered woven boat. (Source: The Sea-Craft of Prehistory, Paul Johnstone)
Boats of this sort were still in use in Iraq as late of 1835. For the coating, the bitumen was heated over a fire, mixed with sand and earth, and applied with a roller.

Thousands of miles away and thousands of years later, similar construction methods are still in use. "Woven Boats of Vietnam," an article by Ken Preston in the current issue of WoodenBoat, describes woven boats of two general types: one small and canoe-like; the other larger and shaped somewhat like the surfboats of India's west coast that I've described previously.

The WoodenBoat article describes the building procedure of the smaller type:
1. The woven fabric is made of bamboo. Long lengths of bamboo are split into narrow strips with a machete, cut to length with a bow saw, then woven by hand on the bias in a simple basket-weave to create a flat piece of matting as wide and long as needed.
2. Stakes are pounded into the ground to define the boat's outline in plan view.
3. Bamboo is split in half lengthwise for gunwales. Half-round lengths are lashed to the inside of the stakes at the height desired, with the flat edge facing inward. This defines the sheer. (Very few boats start at, and are shaped by, the gunwales. The North American birchbark canoe is one example.)
4. The matting is rolled out over the gunwales. Then builder then steps atop the matting and forces it down between the gunwales until it attains a U-shape in cross-section.
5. The remaining half-round sections of long bamboo are lashed inside the hull to form inwales, sandwiching the upper edge of the matting between the two half-round wales.
6. The upper edge of the matting is trimmed flush with the wales, then thwarts and breasthooks are added.
7. The matting is covered with road tar to make it waterproof.

A canoe-style Vietnamese woven boat under construction. The woven matting has been shaped between the gunwales and clamped in place with inwales. The builder is using a bow-drill to bore fastening holes for thwarts. Note the stakes outboard of the gunwales, used to set the outline and height of the gunwales. (Source for this and next photo: "Woven Boats of Vietnam", Ken Preston, in WoodenBoat)
While the canoe-like boat described above has no backbone members and very little stiff wooden structure, the larger, surf-boat types have stem- and stern-posts that are lashed in place. (There appear to be no keels or keelsons to which the stem and sternposts attach.) Boats of this type may be from 17' to 20', and some of the largest ones have diesel engines, although all rely on oars to an extent. Even larger engined versions, from 24' to 30', have wooden upper strakes on top of their woven hulls, and these surely add a great deal of additional stiffness. Although not described in the article, one must assume that some rigid structure serves as an engine bed and keeps the engine aligned with the sternpost through which the shaft presumably passes.

Larger Vietnamese woven boat with wooden upper strakes and endposts. The crew (forward) and their womenfolk (aft) are spinning the boat to "walk" it up the beach.
The sternpost on these boats is hollowed to accept a post for a rudder that can be raised for surf landings. Both stem and sternpost have stout hooks carved on their outboard surfaces that are used to bring the boat up the beach in an interesting manner.

Once the boat lands through the surf, the crew takes a long pole and places it horizontally beneath the hook at the stern. With one or more men at each end of the pole, they lift that end of the boat and pivot it around a point somewhat forward of the boat's midpoint, until the stern is facing up the beach. This moves the boat about 4 feet up the beach. They then move the lifting pole to the bow and repeat the process, switching ends as many times as needed to move the boat beyond the reach of the waves. The process is reversed to launch the boat.

And the advantages  of woven boats? Aside from those cited in the Johnstone quotes above, they would appear to include: i) lighter weight compared to reed floats and dugouts; ii) ease of construction compared to dugouts; and iii) more readily available material in some locations (far less material needed than for floats). Depending upon the application, their flexibility may be either an advantage or a disadvantage compared to dugouts.

With all these advantages, why was the woven boat not more widely distributed? Perhaps it was because suitable waterproofing material was not available in many places. Certainly, natural bitumen is not be be found as readily as reeds, logs, or bark.

On the other hand, not all woven or basket boats rely on bitumen as a sealer. Other Vietnamese woven boats apparently use a dung-based mixture to cover the basketwork, and the Irish coracle was originally a kind of loosely-woven basket covered with skins (as was the Sioux bull boat). It seems possible that other skinboats might have begun their evolution as baskets before attaining the more substantial frameworks that we recognize as the distinguishing feature that separates "skinboats" from woven ones.

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