Medieval to 17th-Century Shipwrecks Uncovered During Swedish Railway Tunnel Project

A routine railway tunnel project in the Swedish coastal town of Varberg has turned into an unexpected archaeological event, after construction crews cut into a buried stretch of the town's medieval waterfront and uncovered the remains of six separate shipwrecks. The vessels range from the Middle Ages to the seventeenth century, with four dating to the medieval or late medieval period, one to the 1600s, and one that has so far resisted every attempt at dating. The find offers archaeologists a rare, layered snapshot of shipbuilding techniques and harbour life across several centuries, all preserved directly beneath what is now the centre of a modern Swedish city.

According to Arkeologerna, the archaeology and cultural heritage unit of Sweden's National Historical Museums, the investigations began in 2019 ahead of construction on the Varberg Tunnel, a major railway project run by the Swedish Transport Administration. The excavation site sits along what was once the town's original shoreline and harbour defence area, a stretch of land that today lies well inland but historically formed part of a busy coastal trading zone. Fieldwork on three of the six wrecks, designated Wrecks 2, 5 and 6, was carried out during the winter and spring of 2022, in partnership with marine archaeologists from Bohuslän Museum, Visuell Arkeologi and Kulturmiljö Halland.

Of the six, Wreck 2 stands out as the most complete and informative. According to Arkeologerna project leader Elisabet Schager, it was the best preserved of the three vessels studied in detail and the only one with a fully connected construction. The ship was built from oak sourced from the Halland and West Sweden region during the second half of the 1530s, using a clinker construction technique in which the hull planks overlap like fish scales, a shipbuilding method rooted in Viking-era tradition that remained common across northern Europe well into the Renaissance. Archaeologists recovered two connected sections of its starboard hull along with scattered timbers during the excavation.

One detail from Wreck 2 has drawn particular attention. Archaeologists identified a berghult, a reinforcing beam fitted to the outside of a ship's hull to protect it while docking, and found clear traces of fire on this component. Schager has described the discovery as especially interesting, since it raises the open question of whether the vessel was damaged by an accidental blaze or deliberately burned before it came to rest at the bottom of the old harbour, a detail that remains unresolved and open to further study.

Wreck 5, also built using the clinker method and dated to the seventeenth century, was recovered quickly due to construction timeline pressures and survived in far poorer condition than Wreck 2. According to Arkeologerna, it was likely built from locally felled oak and would have sailed between medieval Varberg and the nearby town of Ny Varberg, which was ultimately abandoned in the early 1600s. Wreck 6 tells a different story altogether, built using carvel construction, where planks are laid flush edge to edge rather than overlapping, a technique carrying influences from Dutch shipbuilding traditions and notable as the only vessel among the six to retain a preserved keel.

Schager has noted that preserved ship remains have become an increasingly common find along Sweden's west coast in recent years, a pattern she links directly to large-scale infrastructure projects that frequently cut through land that functioned as water and harbour zones during the medieval and early modern periods. As construction continues to expand into these once submerged spaces, similar discoveries are becoming a recognised, if still exciting, part of the process of building modern infrastructure in old coastal towns.

The six wrecks are not the only significant maritime discovery to emerge from the Varberg Tunnel project. In the same general excavation area, archaeologists previously uncovered two medieval cog ships, a distinctive vessel type strongly associated with the Hanseatic trading network, with timber analysis dating one to shortly after 1346 and sourced from timber felled in the Netherlands, Belgium or northeastern France, while the second was built from oak felled between 1355 and 1357 in northern Poland. According to Arkeologerna, only a handful of cog wrecks have ever been found in Sweden, making these earlier finds from the same site especially significant in their own right.

Taken together, the wrecks uncovered during the Varberg Tunnel project offer a rare, continuous record of maritime activity spanning several centuries in a single location, from Viking-influenced clinker construction through to later Dutch-style carvel building. Each vessel represents a different chapter in the town's relationship with the sea, and as excavation and analysis continue, researchers expect the detailed study of timber, construction technique and preservation condition to keep revealing new information about trade routes, shipbuilding practices and harbour life along Sweden's west coast centuries before the modern tunnel construction ever began.