In 2025, during the excavation of a railway tunnel in Varberg, Sweden, workers stumbled upon an unexpected archaeological treasure: six shipwrecks buried under centuries of mud. The temporal diversity of the vessels, spanning from the Middle Ages to the 17th century, has captured the attention of the scientific community. For digital archaeology specialists, this find represents an ideal technical challenge for applying non-invasive documentation techniques.
Virtual reconstruction through photogrammetry and polygonal modeling 🛶
The team of archaeologists has deployed a workflow based on high-resolution photogrammetry to capture every fragment of wood without altering the sediment context. Hundreds of overlapping images are taken from multiple angles, which are then processed in Structure from Motion (SfM) software to generate point clouds and textured 3D meshes. Four of the ships, built with the clinker technique typical of Northern Europe, have been modeled separately to analyze their joints. A flat-bottomed ship, used in medieval trade, and another of Dutch tradition with advanced assemblies, allow for comparing construction evolutions. Fire marks detected on one hull have been digitally mapped to simulate the possible fire prior to sinking.
Mud as a time capsule for Swedish maritime heritage ⏳
This set of shipwrecks not only reveals the evolution of trade routes in the Baltic but also demonstrates how 3D technology allows preserving fragile heritage without extracting it. By generating digital twins of each vessel, researchers can virtually reconstruct their original appearance, study shipbuilding techniques, and map the strategic importance of the port of Varberg. The seabed has acted as a natural archive, and digital archaeology allows us to read its pages without getting them wet.
What was the greatest technical challenge in capturing detailed 3D models of the medieval shipwrecks under the water-saturated mud of the Varberg railway tunnel
(PS: If you dig at a site and find a USB drive, don't plug it in: it could be malware from the Romans.)