Medieval ship sank 600 years ago near Norway. Now some of its mysteries are uncovered

Around 600 years ago, a medium-sized merchant vessel went up in flames and sank off the coast of Norway.

Despite the passage of time, its wooden hull has remained extraordinarily well-preserved under about 3 feet of water near Avaldsnes, a village on the Norwegian island Karmøy.

Now, researchers equipped with sonar have analyzed its charred remains, unraveling some of the long-standing mysteries surrounding the medieval ship, according to a study published on Jan. 16 in the Journal of Maritime Archaeology.

Origins

The wreck, known as the Avaldsnes ship, has been known to researchers for decades, during which time multiple dives have been carried out to learn more about its origins and demise.

These explorations revealed that the ship was made from oak timber originating from modern-day Poland and was constructed between 1392 and 1410.

“Unlike most contemporary merchant ships, this was a fine vessel, built by highly skilled ship builders,” researchers said.

However, not long after it was launched, it plummeted to the seabed of the Avaldsnes port following a fire between 1399 and 1415.

The port was of great strategic importance at the time as it was used by the Hanseatic League, an organization of northern German merchant communities, researchers said.

Despite extensive explorations of the shallow-water site, key questions about the vessel remained unanswered — until now.

Sonar scans

By directing an unmanned catamaran with a sonar system over the wreck, researchers attained detailed measurements of the vessel.

“Operating an unmanned working platform allows for a very time-efficient, (non-invasive) study of the seafloor and the subsurface features by collecting high-resolution seismic data in a dense grid,” researchers said.

Through this method, they found that the vessel stretched 59 feet from bow to stern and had a width of 18 feet.

Using these measurements, they created three-dimensional images of the vessel. One of the images portrays a wooden vessel with a single mast topped with a cross, while another depicts the detailed structure of the hull.

During their sonar sweep, they also uncovered a previously unknown feature resting on the seabed near the wreck.

Buried under several feet of sediment was a mysterious object, likely part of the ship’s rudder or another object “of archaeological importance,” researchers said.

Other “large-scale” objects were picked up during the sonar scans. It’s possible that they are the foundations of a medieval dock, though traditional survey methods have yet to verify them.

Previously a number of artifacts, including ceramics, leather and animal bones were found nearby, providing further evidence for the port, researchers said.

The study suggests that, in the future, noninvasive techniques such as sonar scanning can be used to identify unknown shipwrecks.

This story was originally published January 29, 2024 at 12:21 PM with the headline "Medieval ship sank 600 years ago near Norway. Now some of its mysteries are uncovered."