Practical Knowledge in the Viking Age: the use of mental templates in clinker shipbuilding

It has long been recognized that ships built according to the Nordic clinker tradition during the Viking Age were conceived and constructed simultaneously by eye, in a shell‐first manner, and using rules‐of‐thumb to control both the longitudinal and transversal shape of the hull. While a lot of attention has been paid to the conceptual definition of the keel and stems, far less research has explored how such rules would have worked while planking the hull. Two cargo‐ships, Skuldelev 3 and Skuldelev 1, are used to argue for pre‐design and the use of mental templates. This highlights a cognitive dimension of practical knowledge, in particular how it was accumulated, stored and transmitted.