Archeological artefacts from the shipwreck Gribshunden were CT scanned at the 3D Imaging Center in collaboration with Brendan Foley (Lund University) and Anne Moesgaard (National Museum of Denmark). Gribshunden was the flagship of Danish King Hans I. (1455-1513) and sunk on a diplomatic mission due to a fire onboard in 1495 off the coast of Blekinge (modern day Sweden).
The wreck had already been discovered in the 1970s but archeological investigations were not conducted until the early 2000s. The low salinity of the Baltic Sea has prevented the shipwreck from deteriorating quickly and so large number of well preserved artefacts could be recovered.
Two artefacts were of particular interest, the wooden tankard of King Hans I. and a concretion of silver coins. The tankard was scanned to learn more about the manufacturing process. The 3D rendering in the image clearly shows tool marks produced by the craftsman when shaping the wood.
Through the centuries in the water the silver coins had fused into a concretion which made it difficult for the archeologists to assess the origin of the coins. In the 3D rendering of the CT scan, the stack of coins is digitally cut open which allows to count and measure the coins. By rotating the data, it is actually possibly to read the faces on most of the coins and thus determine their age and the mint that produced them. The CT data will provide the archeologists with additional information to put the excavation site into the historical context and make further discoveries about Scandinavia during the period of the Kalmar Union.
More information about the Gribshunden shipwreck can be found on the website of Blekinge Museum: (www.blekingemuseum.se). The progress of the archeological excavation including the work conducted at the 3D Imaging Center were closely following by a film team from NOVA PBS. A documentary film based on the recorded material will be available in late 2020.