A Roman Ship Scuttled near Salona in the Gulf of Kaštela, Croatia: Excavation, Reconstruction and Analysis

Abstract

Salona (near present-day Split, Croatia), originally an Illyrian city with Greek presence along the eastern Adriatic coast, was conquered by Republican Rome in 76 BCE. Based on its central location in Roman Dalmatia, coupled with a protected harbor in the eastern Gulf of Kaštela and a connection to the hinterlands through the mountain pass of Klis, Salona was the natural choice for the location of the provincial capital. In 2002, the recovery of a 1000-liter perforated dolium in the Trstenik section of Kaštel Sućurac, only three kilometres from the ancient city walls of Salona, attracted the attention of archaeologists to significant Roman remains submerged near shore. In 2006 the outline of a wooden ship was identified, scuttled alongside a submerged wooden wall. In 2015, the ship was uncovered, labelled, recorded using photogrammetry, extensively sampled, then reburied for preservation in situ.

Without completely excavating the wreck, obtaining detailed measurements of all its timbers and conserving the wood remains, the analysis of the wreck and the reconstruction of the hull would depend on its investigation using various computer methods. First, a 3-D model of the ship’s remains was generated using Agisoft PhotoScan. Based on this archaeological data, site plans were generated in ArcGIS to document the wreck. Analysis of the hull remains determined the ship to be a flat-floored, mortise-and-tenon constructed ship, dated to approximately the late 1st century CE and suitable for transport of heavy cargo, reflecting the apex of Imperial Rome’s influence on the eastern coast of the Adriatic Sea.

A reconstruction of the ship’s hull was undertaken in the Rhinoceros 3D modelling program by combining preserved hull curvatures, the full extent of wooden remains exposed on the seabed, and hypothetical hull height based on a review of contemporaneous ships. The Rhinoceros plug-in modules utilized to perform this reconstruction include an iterative draft and displacement calculator, which estimates the Trstenik ship displaced approximately 25 tons. This technique is suitable for extrapolation to other ancient wrecks recorded only by photogrammetry.