Timber for a medieval Cog – Wood studies of the Lootsi 8 wreck, Tallinn.

In April 2022, remains of a ship made of oak were found near the port of Tallinn, at Lootsi Street 8. The first dendrochronological analysis at that time indicated that the wreck was from the late 14 th century. The ship was lifted in four bulk sections, placed at the Estonian Maritime Museum, where a dedicated tent structure was built to protect the wreck, and to allow full excavation of the structure, away from the building site. For the study of the timber, used to build the ship, this has been an ideal solution. Not only has it allowed us ample time for detailed sampling for dendrochronology over two sampling seasons, it has also meant that cross-sections through the ship can be examined. This rare opportunity allowed us to choose good timbers for examination, where we could clearly see where sapwood and even bark edge was preserved, and we could choose timbers from all the ship’s structural contexts: hull planks, reinforcing planks, ceilings and other planking from upper ship structure, and in addition, floors, futtocks, beams, riders etc. Samples were also taken from several loose elements recovered during the in situ excavation in the immediate surroundings of the wreck. We observed, furthermore, that many of the timbers had so-called moon rings (included sapwood). The so-called Lootsi 8 wreck presented an ideal opportunity for us to study this phenomenon, to examine whether the moon rings were synchronous or randomly occurring, in the oaks used for the ship. Trees for the main structure were felled in winter 1370-71 and 1371-72. The upper structure and loose timbers utilised trees felled in winter 1373-74. The material indicates several groups of timbers, indicating the exploitation of several forest regions in coastal Lithuania and a small group of oaks from Estonia.