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Secrets of Europe’s Deepest Lakes

By Fredrik Søreide



Map with the project's site locations.
In 2006, an international team engaged in a project to explore the deep lakes of Norway. The primary focus was to explore for cultural heritage remains and biological research. In the following years, several interesting discoveries were made.

The Telemark Waterway
The Norwegian way of life has always been shaped by the country’s maritime culture. Much has been said about seafaring and maritime culture along the coast, but less is known about the inland waterways, the most important being the Telemark waterway.

Transportation along the lakes and rivers of Telemark dates back to at least the Iron Age. Typical trade goods include whetstones, as well as timber and hides from the forests. Most particularly, whetstones come from quarries in Eidsborg and Lårdal, near the head of the waterway. Precambrian deposits of quartzite are characterized by a fine-veined form that is prone to splitting in two directions, which makes it ideal for use as a whetstone. Though some of the whetstone was transported west across Norway toward cities such as Stavanger and Bergen, most was carried down the Telemark waterway toward the Skagerrak strait and eventually to the rest of Europe where it has been found in archaeological investigations in several countries.

The Telemark waterway in its current form was initiated 150 years ago and was considered at the time to be an engineering marvel. The extensive waterway is 105 kilometers long and rises 72 meters from the sea to its headwaters in the interior. Eighteen locks enable ships to navigate.

Little is known about the trade along the waterway. Promare (Chester, Connecticut) therefore initiated a survey with the Norwegian Maritime Museum, and other research partners, to locate sunken vessels and other cultural remains on the lake floor. The main aim was to learn more about transportation and trade along the route that connected the interior settlements with those along the coast.

Between 2006 and 2009, the team used towed sidescan sonar from Marine Sonic Technology Ltd. (White Marsh, Virginia) and an ROV from Sperre AS (Notodden, Norway) to locate historic shipwrecks ranging from the 17th century to the mid-19th century. In 2010, a larger team from Promare, the Norwegian Maritime Museum, the Norwegian University of Science and Technology and Teledyne Hafmynd (Kópavogur, Iceland) used a Gavia AUV to locate nearly two-dozen well-preserved shipwrecks in Lakes Bandak and Kvitseid. The Gavia AUV proved to be an invaluable asset during the operation in Telemark due to the very steep walls of the virtually uncharted deep lakes. In 2012, the team returned with an ROV from Sperre AS to identify the sonar targets discovered in 2010.

Due to the cold freshwater of the Norwegian lakes, the shipwrecks located are in excellent condition. Though it is difficult to specifically date some of the targets without removing samples, we determined that there are a range of vessel types and sizes, including some very interesting cargo vessels. The oldest of the about 20 vessels discovered and documented during this work is a 17th-century whetstone barge, complete with whetstone cargo. Additional mounds of whetstone may hide even older craft. It seems as if the trade in whetstones has resulted in the construction of a very particular barge type.

From the appearance of the rest of the vessels, it is likely that they are not more than 200 to 300 years old. The team discovered two nearly identical 19th-century barges, one of which was still loaded with timber, indicating a standardization of goods transport in that century.

In addition, the Norwegian Maritime Museum discovered several shipwrecks at the mouth of the waterway close to Skien, including a 14th-century cargo vessel loaded with whetstones.


Hitler’s Sunken Secret
Hydroelectric power in Rjukan, Norway, was developed after Sam Eyde won approval for an idea of the industrial production of nitric using the so-called arc, which required large amounts of electricity. A byproduct of the production at Rjukan was heavy water. Heavy water was at one time an ideal reducing agent or moderator in nuclear reactors. While Americans focused on graphite as a moderator in its nuclear reactor experiments, the German experiments were based on heavy water as a moderator. Because the German occupation forces in Norway were interested in heavy water, Rjukan was an important goal for Norwegian and Allied saboteurs during World War II. Bomb attacks in the factory led to its closing. Heavy water equipment was dismantled and shipped to Germany. The remaining inventory of heavy water, about 50 barrels, was also transported to Germany. During transport, in February 1944, the ferry Hydro was sunk with the heavy water barrels, after three saboteurs had succeeded in placing an explosive on board. However, rumors persisted that the Germans had managed to replace the barrels on board, and that the barrels on board did not contain heavy water. To continue this article please click here.


Fredrik Søreide is the vice president of Promare and is responsible for its deepwater exploration initiative. He is also a professor of marine engineering at the Norwegian University of Science and Technology. He has been involved in numerous marine scientific and exploration projects around the world.




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