A new insight into the sheathing of early 19th-century French warships: SEM-EDX and ICP-MS analyses of copper-based samples from the Lion (1809) and Robuste (1809)

Materials characterisation has largely been applied to the study of modern shipwrecks, providing valuable data for dating, provenance, and technological assessment. The comparison between vessels from the same period and origin, however, is less common. A comparative approach based on fine-grained data retrieved from intra-fleet warships, for instance, can help to identify their service histories and detect short-term technological or supply-related changes. In this article, we present the results of SEM-EDX and ICP-MS analyses of copper-based sheets and sheathing tacks retrieved from the Lion (1804–1809) and Robuste (1806–1809) shipwrecks. Based on microstructural and chemical composition data, we propose a preliminary assessment of their manufacture. Considering documentary evidence related to both vessels and previous archaeometric data from two other French shipwrecks, we discuss the copper-based materials used for hull protection in early 19th-century French shipbuilding. We also highlight how these early results help to refine hypotheses on wartime supply refitting practices and intra-fleet manufacturing variability.