Lashed-lug boat
The planks are further stitched together edge-to-edge by sewing or using dowels ("treenails") unto a dugout keel and the solid carved wood pieces that form the caps for the prow and stern.
[1][2]: 297–302 [3][4] Lashed-lug construction has been used on a wide size range of vessels, from small craft, such as logboats that have had planks added to their sides to increase their freeboard, to large plank-built ships.
[3][6] The seams of the planks were commonly caulked with resin-based pastes made from various plants as well as tapa bark and fibers which would expand when wet, further tightening joints and making the hull watertight.
[3] Once the shell of the boat is completed, the ribs are then built and lashed to the lugs to further strengthen the structure of the ship, while still retaining the inherent flexibility of the outer hull.
[1]: 297 In archaeological remains that date from the beginning of the second millennium CE, the number of dowels used to join hull planking increased and stitching ceased to be used.
[1] Lashed-lug techniques are different enough from the shipbuilding methods of South Asia, the Middle East, and China to identify remains of ships found in this region as being Austronesian.
[10][11][12][13][14] The partial remains of the even earlier Pak Klong Kluay shipwreck (c. 2nd century CE) of Thailand also features lugs, although its planks are uniquely joined using pegged mortise and tenon joints, instead of dowels or sewing.
[11] Archaeological evidence of lashed-lug ships from 1500 BCE to 1300 CE remains negligible due to the perishable nature of wooden vessels in the tropics.
[16] The oldest evidence of the lashed-lug techniques, however, are found on boat-shaped log coffins recovered from Kuala Selinsing in Perak, Malaysia, dated to around the 1st to 2nd centuries CE.
However, the development of metallurgy in Maritime Southeast Asia in the last two thousand years resulted in the replacement of the sewing technique with internal dowels, as well as increasing use of metal nails.
An earlier example (400-300 BCE), the Hjortspring boat is based on a dugout log which is expanded with sewn clinker planks with integral cleats/lugs lashed to framing.
