The Effect of Changing the Beam of an Ancient Ship’s Hull on Its Capacity, Stability, and Performance

Abstract

Wooden ships on the shipwreck sites are usually only partially preserved, and reconstructing the original hull lines requires considerable effort. The shape of the hull has a direct effect on the ship’s capacity to carry cargo, as well as on its speed and stability. When reconstructing the hull lines, the incomplete nature of the archaeological remains results in the interpretation of the available data. The outcome, therefore, depends on the assumptions and decisions associated with the reconstruction process. This paper examines how the variation in a single parameter, namely, the beam, affects the performance of the vessel. Considering the availability of the model, the Kyrenia ship from the fourth/third century BC is used as a case study. The scope of this paper is to demonstrate and quantify the effect of beam variation on ancient ship performance, namely, the ship cargo capacity, stability, and resistance. Kyrenia ship was used as a study case based on hull lines proposed by Steffy in 1985. The aim is not to modify Steffy’s original reconstruction but to demonstrate that small deviations could significantly affect the performance of the vessel. In addition, an increase in the height of the ship’s sides is proposed as a possible solution to increase the load capacity of the ship. The opportunity to explore a whole set of trials and reconstructive variations with naval engineering software can deepen our understanding of ship performance, allowing us to improve our approach to reconstruction, too.