A Parametric Model of the Portuguese Nau

Abstract

This interdisciplinary research project combines the fields of nautical archaeology and computer visualization in order to create an interactive virtual reconstruction of a Portuguese nau. Information about the shipbuilding process is gathered from 16th and 17th century treaties by Fernando Oliveira and Joao Batista Lavanha, as well as from Dr. Filipe Castro (Texas A&M Department of Anthropology). Eight registered tonnage formulas from the 15th to 17th century are used to estimate the cargo capacity of the nau. Using this information, I develop an algorithm that creates a parametric computer model of a nau hull and calculates its registered tonnage. This parametric model allows the user to choose between the Oliveira and Lavanha hull shapes, adjust parameters to fine tune the hull shape further, and save the information about the hull shape for future editing. The eight registered tonnage estimates are compared to the volume of the parametric hull model below a generic waterline.

The process I use to adapt the information provided by the two shipbuilding treatises into an algorithm determines the hull shape of a nau. This allows for projects in the future to introduce other shipbuilding approaches and information as it becomes available to this parametric model.