Preserving the wreck of the Mary Rose, in: P
- A. M. Jones, M. H. Rule
- Hoffmann, Ed., Proceedings of the 4th ICOM Group…
Maximum moisture content (Umax) “profiles” were produced throughout cut cross-sections of waterlogged archaeological oak, poplar and pine timbers, and the distribution of values compared to visible degradation patterns. Attempts were then made to classify the degree of degradation in each timber. Where appropriate, comparisons were made with the established classification scheme of de Jong (1977), for waterlogged archaeological oak. Numerical classification schemes were investigated after statistically analysing Umax data ranges for each of the three species. Moisture content profiles from all timber sections reflected visible degradation patterns, supporting the use of Umax data as an indicator of preservation state. Incorporating numerical data in to a classification system presented potential problems, as large ranges of values were common within individual timbers. Numerical schemes were suggested however, by incorporating two ranges of Umax values, which separate well preserved and degraded regions respectively. Umax ranges were unique to the individual species studied and a generalised scheme was not possible. A generic classification system based on visual appearance or physical examination is proposed, by modifying de Jong’s scheme for European oak, which compares relative proportions of well preserved versus degraded material. Collectively, results provide reference data for assessing similar timbers, where large destructive samples cannot be taken.