The western spatial extent of the Claudius Harbour moles in Portus is well established after the collection and analysis of numerous sediment cores (Morelli et al., 2001) and geophysical surveys (Keay et al., 2009) conducted over the past fifteen years. Recent research focuses on determining whether ancient Roman harbour infrastructures were constructive, specifically the moles that were built to protect the harbour. The objective of this study is to provide a higher resolution sedimentological reconstruction of the western Claudian Northern Mole (NM) in order to ascertain the effectiveness of the structure and its impact on the regional coastal environment. This project will involve examining three sediment cores (CL32-10m, CL31-16m, and CL30-22m) collected around the NM (Figure). A combination of sedimentological analysis (e.g. grain size and mineralogical identification using Mid-Infrared Spectrometry [MIR]) and biostratigraphic analysis will be conducted as well as radiocarbon dating of macrofossils for age-depth modelling. This research is important for understanding the engineering complexities behind ancient Roman harbours and will provide further contextual background for archaeological research in Portus.