Concept
Clinker built (also known as lapstrake) is a method of boat building in which the edges of hull planks overlap each other. Where necessary in larger craft, shorter planks can be joined end to end, creating a longer strake or hull plank. The technique originated in Scandinavia, and was successfully used by the Anglo-Saxons, Frisians, and Scandinavians, typically in the vessels known as cogs, employed by the Hanseatic League. Carvel construction, where plank edges are butted smoothly, seam to seam, supplanted clinker construction in large vessels as the demand for capacity surpassed the limits of clinker construction, such as in the larger hulks. (See Comparison between clinker and carvel below.). Examples of clinker-built boats that are directly descended from those of the early medieval period are seen in the traditional round-bottomed Thames skiffs, and the larger (originally) cargo-carrying Norfolk wherries of England. From clinch, or clench, a common Germanic word, meaning “to fasten together”. The technique of clinker developed in the Nordic shipbuilding tradition as distinct from the Mediterranean mortise and tenon planking technique which was introduced to the provinces of the north in the wake of Roman expansion. Although overlapping seems to already appear in the 4th-century BC Hjortspring boats, the oldest evidence for a clinker-built vessel, dendrochronologically dated to 190 AD, are boat fragments which were found in excavations at the site of the Nydam Boat. The Nydam Boat itself, built 320 AD, is the oldest preserved clinker-built boat. Clinker-built ships were a trademark of Northern European navigation throughout the Middle Ages, particularly of the longships of the Viking raiders and traders, as well as the trading cogs of the Hanseatic League. Clinker built vessels were constructed as far South as the Basque country. File:Nydamboat.2.jpg|Clinker hull of the [[Nydam Boat]] from [[Jutland]] File:Exhibition in Viking Ship Museum, Oslo 01.jpg|Clinkered prow of the Viking [[Oseberg ship]] File:Kogge stralsund.
