The Kettuvallom or 'boat with knots' is so called because the entire boat is held together with coir knots only - not a single nail is used during the construction. The boat is made of huge planks of Jack wood (Artocarpus hirsuta) or
'Aanjili' and joined with coir. This is then coated with a caustic black resin made from boiled
A portion of the Kettuvallom is covered with a canopy made of the wood from the arecanut tree and bamboo mats and coir and served in the old days as a rest room and kitchen for the crews. Kettuvalloms were formerly used for the transport of goods like rice, spices and coir from the isolated villages of the interior to the towns.
A Kettuvallom, which measures from 20 - 25m in length and from 4m - 4.5m across, can hold up to 30 tons of cargo. Two men punting at each end with long bamboo poles moved these huge barges. With the advent of roads, bridges and modern transportation, these Kettuvallom gradually disappeared from use. There used to be an entire clan of artisans who were involved in Kettuvallom construction.