A preliminary assessment of the state of preservation of the wreck of the Belgica

Abstract

Introduction The raising of a wooden shipwreck is a large undertaking, both the practicalities of excavating and lifting, and the requisite long term commitment of funding and personnel to its subsequent conservation, exhibition and curation. In reality, although technically challenging, the actual raising of a wreck takes the shortest time in the whole process. The subsequent conservation can take many years, followed by continual curation. However, as attested by the finds of the Vasa6, Skuldelev ships7 and Mary Rose8, which were discovered and excavated between the 1950s and 1980s, shipwrecks provide an important insight into maritime history both academically and through their public presentation. Prior to attempting to raise a wreck it is important to carry out a pre-disturbance survey in situ, in order to obtain a better understanding of its state of preservation. This is useful both in terms of designing a lifting strategy and in terms of advance planning of the conservation process. For example, the integral strength of the remaining wood determines if it is responsible to raise the wreck as a complete unit, or if it requires disassembly and lifting in separate sections/pieces. Furthermore, knowledge of the state of preservation of the wood can help in construction of holding tanks for impregnation and designing the optimal processes in terms of impregnation materials and drying regimes. Such a pre-disturbance survey of the state of preservation of the wreck of the Belgica was carried out in connection with proposals to raise her. The aims of the assessment were fourfold: Ȇ To get an overall impression of the strength of the wood from the Belgica, through in situ measurements and on samples of wood taken from the site. Ȇ To assess the presence and on going activity of macro wood boring organisms (molluscs such as Teredo navalis (shipworm) and crustaceans, such as Limnoria tripunctata (gribble)). Ȇ To analyse the wood to see if inorganic compounds were present, these may affect the subsequent conservation of the wreck should it be raised. Ȇ To test the developed assessment methodology on a large wooden shipwreck lying out at sea and by doing so contributing to conservation issues in maritime archaeology.