In the context of the simultaneous exhibition “8 Objects, 8 Museums” by the Leibniz research museums, the German Maritime Museum in Bremerhaven presents the salvage, preservation and presentation of the Bremen Cog.
Since the 19th century, the idealised cog has been considered the most successful type of ship of its time in the North and a symbol of the Hanseatic League. The Hanseatic League or Hansa (literally: troop) was formed in the 12th century initially as a loose association of merchants, and from the 14th century on, it also included cities and towns. Its purpose was to offer its members support, protection and political clout in foreign trading places.
As a provisional measure, the cog is now kept in shape with the help of metal supports and is under observation using 3D measuring methods. In order to develop a reliable monitoring system and a long-term concept for the cog’s presentation, the German Maritime Museum compares the collected data by means of data fusion.
Photogrammetry uses a large number of photographic images to create a 3D model. The problem: In order for the images to be truly meaningful, they must be shot from exactly the same position and under comparable lighting conditions.
In laser scanning, the object is captured by laser beams. The data are used to compute a three-dimensional, rotatable image of the ship that enables observation from different perspectives. The problem: Depending on the scanner’s angle, the object’s dimensions are not captured correctly and are represented with distortions.
In the total station measuring method, a certain number of points on the ship are scanned. They form the framework for constructing a 3D object. Since it concentrates on fixed points, the method is very precise. However, it is also problematic: a dense network of permanently installed measuring points restricts the view of the object.
The museum’s research focus is on historical questions - e.g., the history of sea ports and merchant shipping. A current research project explores the question how seafaring and trade were conducted between the North Atlantic islands and the Hanseatic cities when the battle for the stockfish trade errupted.
“8 Objects, 8 Museums” is a collaboration project between the Leibniz research museums and the Leibniz-Institut für Wissensmedien in Tübingen in the Leibniz Year 2016.
Research and exhibition project by the German Maritime Museum regarding the “Bremen Cog”
All documents and photos:
German Maritime Museum, Photos: Captair, Felix Clebowski, Per Hoffmann, Erik Hoops, Hans-Jörg Kröhnert, Egbert Laska, Günter Meierdierks, Frederic Theis, Annika Thöt, Daniela Wittenberg
Text and object selection: Ruth Schilling, Stephan Speicher, Frederic Theis
Collaboration: Marleen von Bargen, Amandine Colson, Sunhild Kleingärtner, Tobias Wulf
Translation: Hendrik Herlyn
Mike Belasus, Tradition und Wandel im neuzeitlichen Klinkerschiffbau der Ostsee am Beispiel der Schiffsfunde Poel 11 und Hiddensee 12 aus Mecklenburg-Vorpommern (Rostock 2014).
Jörgen Bracker (Hrsg.), Die Hanse. Lebenswirklichkeit und Mythos (Hamburg 1989).
Amandine Colson – Julien Guery – Massimiliano Ditta, „Bremen Cog“ – Long term monitoring of deformation process, in: Condition, conservation and digitalisation. Conference proceedings, Gdansk National Maritime Museum (Danzig 2015), 107-111.
Gabriele Hoffmann – Uwe Schnall (Hrsg.), Die Kogge. Sternstunde der deutschen Schiffsarchäologie, Schriften des Deutschen Schiffahrtsmuseums 60 (Hamburg 2003).
Natascha Mehler – Mark Gardiner, On the Verge of Colonialism: English and Hanseatic Trade in the North Atlantic Islands, in: Peter Pope – Shannon Lewis-Simpson (Hrsg.), Exploring Atlantic Transitions: Archaeologies of Permanence and Transience in New Found Lands. Society of Post-Medieval Archaeology Monograph 8 (Woodbrige 2013), 1–15.