Two unique medieval shipwrecks known as cogwheels have been discovered at the Varberg archaeological dig site in Sweden. The personal belongings of the crew recovered inside the wreck provide information about life at sea.
Wheelbarrows were sturdy, wide-beamed ships commonly used in Baltic and North Sea trade from the 12th to the 15th centuries. They were primarily used to transport goods such as grain, timber, and textiles over long distances.
Often seen as the successor to the Viking Age knarr, the paddle wheel was designed to maximize cargo space.
It shows that the wheels unearthed in Sweden were built outside of Scandinavia in the mid-14th century.
Archaeologist Elisabet Schager, project leader of the National Historical Museums of Sweden excavation, said: “These shipwrecks are a very special find, both in Sweden and abroad, so it was great to find them. Before these two shipwrecks were discovered, only 7 more cogs were known in Sweden, and only around 30 were known all over Europe.”
The first dendrochronological (tree ring dating) samples were analyzed. The results show that Varbergskoggen 1 was built with timber cut after 1346 in what is today the Netherlands, Belgium and northeastern France, while the smaller Varbergskoggen 2 (Varberg Cog 2) was oak cut between 1355 and 1357 in northern Poland. indicates that it was collected from the tree. These results show that both ships were lost in foreign waters, far from home, eventually under the waves.
During the excavation of the wrecks, various construction details were recorded, all of which are identifiable features by traditional gear construction. For example, the lower straps of the ships are built in the carvel style, while the sides are built in the more traditional clinker style. Also, the caulking between the straps is made with moss and fixed with lathes. The decks are supported by bulky beams attached to the sides of the hull.
Personal items reveal information about marine life
Archaeologists have also unearthed a wide variety of fascinating artifacts, including leather shoes and household items made of wood and ceramics. At Varbergskoggen 1 (Varberg Cog 1, the larger of the two), rare cache ship equipment and spares have been discovered, protected from wreck looters by a pile of ballast stone.
Stating that a wide variety of personal objects were found representing parts of the crew’s daily routines, such as wooden bowls and spoons, Schager said: “Among the wreckage, a number of barrel covers were also uncovered, some of which looked like traces of the maker. We’ve also collected and analyzed soil samples, hopefully we can identify food and/or cargo residues. We will even look for parasitic remains that can determine if animals were kept on board, and if so which species. We hope to be able to piece together where the cogs’ fateful journey originated and where they are going.”
More analyzes are being worked on to help add more precision to the dating of the shipwrecks, and even to understand how long they were used before their demise.
The reason for the sinking of the impellers is still not clear. “After clearing each timber of debris and critically analyzing it, I hope we can get to the bottom of the mystery. The information we could gather from the initial excavation was that the larger Varbergskoggen 1 rolled into the harbor side in shallow water while still rogue,” says Schager.