60 Years of the Cog Find: An Excavator Unlocks Hanseatic History

The Bremen Cog: sensational find - research object - milestone in shipping history. October 8, 2022 marks the 60th anniversary of its discovery. Celebrated today, almost overlooked then: The recovery of the world's best-preserved medieval merchant ship began with trouble at a construction site. The Kogge Fund anniversary is celebrated by the German Maritime Museum (DSM) / Leibniz Institute for Maritime History with the opening of the interactive shipyard model showing shipbuilding 4.0.

Wood, always hard, heavy wood clogs the so-called stone box of the Belgian suction hopper dredger "Arlesienne" on which Albert Baumann is on duty in the night of October 8-9, 1962. The deck crew from Belgium, Holland and Germany sweat, groan and swear because the pump is on strike. Baumann, 24, from Greetsiel, actually earns his money in fishing. In his home country, however, there is a lack of orders. In Bremen, business is booming at the Port of Europe and a new turning basin is needed quickly. So Baumann hires on as a deckhand on the suction dredger, working night shifts to drive the expansion forward. Where sand is supposed to be excavated, he now steadily fishes wood from the depths of the Weser. He drags the pieces of wood into a rowboat and throws them onto a sports field on the bank. "I immediately saw that it was oak wood. That it was an old ship, however, was not to be thought of. We couldn't recognize it at night." The next morning, the groundskeeper from the sports field has already disposed of the centuries-old frames. In the water of the Weser, the outline of a ship that has tipped over onto its side is suddenly visible. Despite the high time pressure, the deckhands stop work for the time being. Puzzled, they look at the wooden skeleton they have unearthed.

Sensational find - and still a research project

What kind of ship is it? Baumann has no idea that he and his colleagues have stumbled upon a cultural and historical treasure - the Bremen cog from 1380, the best preserved merchant ship of the Middle Ages and today the DSM's leading exhibit. Siegfried Fliedner, head of the shipping department at Bremen's Focke Museum, rushes to the site in the morning, examines the wreck and determines it to be a Cog.

After the salvage, the challenges are great: A puzzle of more than 2000 pieces wants to be put together. The interdisciplinary science team is spending a long time investigating how the centuries-old wooden structure can be permanently displayed. Weser silt has preserved the wreck perfectly so far. When exposed to air, the wood threatens to deform and crumble. Wood chemists find a method that paves the way for the preservation of other wooden ships, such as the Swedish Vasa. An important step in hardening the wood is the nearly 20-year bath in the artificial wax polyethylene glycol (PEG). It was not until 2000, 38 years after the find, that reconstruction and the highly complex conservation process were completed.

Even 60 years after its discovery, the cog remains in the focus of science: modern methods of preventive conservation such as photogrammetry are regularly used to determine whether the wood continues to work.

Later, when Albert Baumann stands in front of the reconstructed Cog at the DSM, he marvels at the 20-meter-long and eight-meter-wide wreck. The incomplete side makes him wonder: "Those were certainly the frames that we accidentally dredged back then," recalls the now 84-year-old man from Wahl Bremen. "We had no idea that we had stumbled upon a sensational find." Today, a small metal sculpture on the banks of the Weser commemorates the historic find in Bremen-Woltmershausen.
 
DSM celebrates the cog - shipbuilding past and present

On the 60th anniversary of the find, the DSM invites visitors to an exciting look at shipbuilding today. Right next to the medieval merchant ship, the interactive shipyard model offers insight into shipbuilding today. The special exhibition "Steel and Bytes - A Ship is Built" can be visited from 1 p.m. on Saturday, October 1.

Results of the latest research projects around the cog will soon be on display in exhibitions: "Ever onward - the Hanseatic League in the North Atlantic" opens in spring 2023. The show shows that Bremen and Hamburg merchants were already bringing goods to the northern Scottish Shetlands and Orkney in the days of the Hanseatic League.
For the project "Digital Materialities. Virtual and Analogue Forms of Exhibition" project, among other things, finds from the cog are being examined using the latest scanning technology. The objects and digital copies will be on display from fall 2023.