An ammunition box was found behind a sunken medieval ship (4 photos)
A thorough study of the sunken ship "Gripshunden" revealed many new finds: information about the combat platforms of warships and a unique weapons chest from the late Middle Ages. 
The research was carried out in collaboration with underwater archaeologists from Södertörn University and CEMAS/Institute of Archeology and Ancient Culture at Stockholm University.
The Gripshunden (also known as the Griffon or Griffon Hound) was the flagship of King Johann I of Denmark (1481–1513), ruler of the Kalmar Union. In 1495, the Danish warship Gripshunden sank off the coast of Sweden. The wreck was discovered in the 1970s by recreational divers, but was not known to researchers until 2000. 
Photo: Florian Huber
The last field work on the sunken ship was carried out in May last year.
The research team, led by Professor Johan Rönnby from Södertörn University and PhD candidate Rolf Warming from Stockholm University, used underwater cameras and 3D photogrammetric technologies to examine and document additional parts of the ship's remains.
Key findings include the discovery of a wooden weapons chest, analysis of chain mail, and a better understanding of the ship's superstructure. 
Ammunition box (Zeuglade in German) with contents. The solid line shows the elongated side of the box, the dotted lines show the approximate location of its sides. Contents: (1) lead plates, (2-3) molds, (4) elongated side of chest along with iron corrosion (from lock and fittings?), (5) cylindrical "cans" (possibly gunpowder containers) and (6) mold. Photo: Florian Huber, notes and notes by Rolf Warming
The exploration of the chest was one of the most significant discoveries made during the last dive. Taking high-resolution photographs, the researchers determined its contents. This is the Zeuglade, a box for storing and producing ammunition, which, as we know from illustrations of the time, often accompanied armies on the battlefield.
“The contents of the chest are heavily rusted, but appear to consist of several different items located within a large crust of rusted iron. The crust contains several sharp flint fragments which can be interpreted as part of canister shot ammunition... In the northern half of the remains two oblong pieces of lead plate with holes along the edge (presumably to facilitate the casting process) and at least three stone molds for lead can be identified bullets of different calibers. The molds were intended to make bullets for handguns such as pistols, as well as larger caliber firearms, perhaps arquebuses or small breech-loading guns,” the researchers write.
The chest and its contents likely belonged to German mercenaries who were on board when the Gripshunden sank. This is undoubtedly an important artifact of medieval military technology.
Researchers have identified a significant portion of the ship's superstructure that survived despite the logs being splintered and scattered across the seabed, mapping the logs at the wreck site. This can provide important clues about what the superstructure looked like and therefore the military capabilities of the ship. 
Decorative border of riveted brass rings for a chain mail (hauberk) analyzed in connection with diving. Chain mail of this quality could consist of 150,000 rings. Photo: Rolf Warming
In addition to diving work, a study of previously found fragments of chain mail was carried out. In collaboration with Professor Kerstin Lidén from the Archaeological Research Laboratory at Stockholm University, the researchers found that the chainmail weave had multiple threads and manufacturing methods, suggesting that it had been repaired several times. Such armor could hold up to 150,000 rings, judging by the size of the surviving rings.
Previous dives led by Professor Johan Rönnby had found medieval firearms and a drinking stein, and research suggests the ship was most likely built in the southern Netherlands.
