3D documentation and monitoring of the experimental cleaning operations in the underwater archaeological site of Baia (Italy)

The CoMAS project aims to develop new methodologies and tools for the restoration and conservation of submerged archaeological artefacts. One of the project goals is to study the cleaning operations that are intended to remove the living organisms (algae, sponges, molluscs, etc.). These organisms cause severe deteriorations of the artefacts and their removal is crucial for the subsequent phases of consolidation and protection. In particular, the Unit of Underwater Archaeology of the Istituto Superiore per la Conservazione ed il Restauro is experimenting and comparing different cleaning techniques and tools developed in the context of the CoMAS project. This comparison requires also a precise documentation of the test cases and a quantitative measurement of the effectiveness of the cleaning procedures. This paper describes the process that has been defined in order to document and monitor the results obtained through different cleaning experiments, conducted with different tools and utensils over various types of surfaces (marble, bricks, mortar, etc.) affected by several types of biological colonization. The process includes: 1) the 3D mapping of the experimental site; 2) the planning of the tests and the choice of the areas to be cleaned; 3) the 3D reconstruction of the selected areas; 4) the execution of cleaning operations; 5) the 3D acquisition of the cleaned areas; 6) the comparison of the 3D model of the areas before and after the cleaning; 7) the analysis of the data about the cleaning effectiveness. This process has been implemented during an experimentation carried out in the "Villa dei Pisoni", located within the underwater archaeological site of Baia near Naples.