Sewn boat

A sewn boat is a type of wooden boat or ship which is clinker built and held together with tendons or flexible wood, such as roots and willow branches. Sewn boat construction techniques were used in many parts of the world prior to the development of metal fasteners, and continued to be used long after that time for small boats to reduce construction costs where metal fasteners were too expensive.

Name and similar techniques

Although well established, the "sewn boat" name is somewhat misleading since it suggests textile or leather skin construction, as often found in kayaks. Some have proposed to use "laced boats" (Ge. "geschnürte Boote") instead. A modern plywood construction method that resembles sewn boats is the stitch and glue method; in this technique plywood panels are stitched together, often with wire, and the seams are reinforced with fiberglass composite; the stitching may then be removed or may remain in place.

Construction

Sewn boats start with the construction of the "skin" of the boat, rather than the "frame", resulting in a monocoque type of structure. Carefully shaped planks are connected at the edges, usually in the clinker style, with overlapping sections which are sewn together. As the planks are placed together, the skin begins to bend into the desired shape. The resulting structure is highly flexible. Internal framing may be added to the planks after they are sewn in, providing additional rigidity.

While wooden pegs (often called "treenails") can be used to fasten thicker clinker planks, this technique only works if the planks are thick enough to hold the pegs. Because of this, large ships were often built using pegs, while smaller boats would use sewn planks.

History

The earliest example of a sewn boat comes from North Ferriby, where one sample (called "F2") carbon dates to 1930-1750 BC. Later finds include some early Greek ships. The oldest Nordic find is the Hjortspring boat in Denmark (c 300 BC). In Finland, Russia, Karelia and Estonia small sewn boats have been constructed more recently, until the 1920s in poor areas of Russia.

While European sewn boats are the best known, sewn boats existed in many areas, often as the next step from a dugout canoe [http://www.ferribyboats.co.uk/boathistory/index.html] . An example of a non-European sewn boat is the Micronesian proa. Sewn boats are important in the study of Viking Age longships, which use the basic architecture of sewn boats, although they make use of metal fasteners.

External links

* [http://home6.inet.tele.dk/hjortspr/ A full-scale replica of a Hjortspring Boat] , an early Viking sewn boat
* [http://www.foteviken.se/sewnboat/ Reconstruction] of sewing boatbuilding technique & building of a sewn boat replica at Fotevikens museum
* [http://anthropology.tamu.edu/abstracts/theses/adams.htm Abstract] of "Construction and Qualitative Analysis of a Sewn Boat of the Western Indian Ocean"
* [http://www.abc.se/~pa/uwa/glossary.htm Underwater Archaeology Glossary] definition of "sewn boat"
* [http://www.ferribyboats.co.uk/ Ferriby Boats] website, with information on archeological finds
* [http://links.jstor.org/sici?sici=0002-9114%28199107%2995%3A3%3C441%3AO5AHSC%3E2.0.CO%3B2-7&size=LARGE Odyssey 5.234-53 and Homeric Ship Construction: A Reappraisal] , an analysis of Iron Age Greek ship "laced boat" construction methods