They discover a medieval ship that could be up to 700 years old sunk in the largest lake in Norway

() — At the bottom of Lake Mjøsa, the largest in Norway, rests a shipwreck from hundreds of years ago in an almost perfect state, frozen in time.

The vessel, with its unique bow posts and overlapping planks, reveals a moment in the lake’s maritime history, estimated to date from between the 1300s and 1800s.

the researchers they discovered the shipwreck while conducting the Mission Mjøsa project, which aims to map the 363-square-kilometre lake bed using high-resolution sonar technology.

The Norwegian Defense Research Establishment He led the mission two years after conducting several remotely operated vehicle, or ROV, inspections of areas of the lake where large amounts of munitions had been dumped. The lake is a source of drinking water for about 100,000 people in Norway, according to the Norwegian University of Science and Technology, so the ammunition posed a health risk. The wreck was discovered during exploration of the lake.

The Mission Mjøsa project uses sonar to map the lake bed and locate dangerous munitions. Credit: Courtesy NTNU/FFI

“I expected that shipwrecks would also be discovered while mapping ammunition dumps, and they were,” explains Øyvind Ødegård, Principal Investigator for Marine Archeology at the Norwegian University of Science and Technology and Principal Investigator on the mission. “The statistical probability of finding well-preserved wrecks was simply considered to be quite high.”

possible medieval ship

The recently discovered wreck lies at a depth of about 411 meters and was captured on sonar images, a system that uses sound pulses to detect and measure the area under the surface of the water. The images revealed that the ship was 10 meters long.

The freshwater environment and lack of wave activity at that depth kept the ship in pristine condition, save for the corrosion of a few iron nails at each end of the ship. For Ødegård, the weathering of the metal is a dead giveaway that the wreck has been resting on the lake bed for quite some time, as corrosion would take hundreds of years to occur. Over time, the ship could lose its structure when all the nails disintegrate, she said.

In the stern section of the boat there are indications that there is a central rudder, an element used for steering, which does not usually appear before the end of the 13th century. Combining these two features, the archaeologists calculated that the ship was not before 1300 and not after 1850.

The ship seems to have been built using a Nordic technique, in which the planks of the body overlap each other. This method was used in the Viking Age to make the ship lighter and stronger, and is known as “clinker construction”.

As the wrecked ship was found in the middle of the lake, Ødegård believed that it had sunk due to bad weather. The ship most likely used square-shaped sails, he added, which were difficult for sailors caught in extreme wind conditions to navigate.

Norwegian history

The oldest vessel discovered in Norwegian waters to date is the rowing boat Sørum, found in the barriers of Bingen, on the Glomma river, and dated to 170 BC The wreck, almost 2,200 years old, was relatively well preserved for being thousands of years old.

“Wooden shipwrecks can be kept very well in freshwater, as they are devoid of the wood-eating organisms found, for example, in the ocean,” explains Ødegård. “I suppose if we are going to find intact Iron Age or medieval vehicles in Norway then (Lake Mjøsa) would be the place to look as it is large enough to have had its own distinct maritime history with a lot of shipping and Commerce”.

During the Viking Age, the lake served as a great trade route, although some details of before and during these times are not yet known, according to Ødegård. “Whatever the era, any find will help us better understand how the shipbuilding tradition on an inland lake developed, compared to the Nordic countries.”

more to explore

To map the bottom of the lake, the research team used a state-of-the-art autonomous underwater vehicle called Hugin, from Norwegian technology company Kongsberg Maritime. According to Ødegård, this is the first time such equipment has been used in a freshwater environment, and it has not seen much use in archaeology. He called Hugin’s use on this occasion an “unusual luxury.”

The Hugin autonomous underwater vehicle (pictured) is used for the first time in a freshwater environment to study the lakebed of Mjøsa in Norway. Courtesy NTNU/FFI

On the last day of the exploration, the researchers had sent an ROV to try to capture images of the wreck, but had to abort the mission due to bad weather. Ødegård plans to return next year to try again.

Meanwhile, the researchers continue to map the bottom of the lake. To date, they have only mapped 39 square kilometers and still have a long way to go. Ødegård said that he foresees more shipwrecks being discovered.

“We could find boats from the beginning of human activity in the area. They could be present and in good condition,” Ødegård said. “Nothing can be ruled out.”