The use of massive data capture techniques in architectural heritage has enhanced the development of new methodologies that have an important impact on their conservation and understanding. The research proposes the study of formal anomalies in the cloister of the Cathedral of Tarragona (c. 12th century). It is a relevant Gothic construction in Catalonia, with the special singularity that part of its structure is raised over an important pre-existing Roman wall. The investigation is based on a point cloud obtained with a terrestrial laser scanner (TLS) and the systematization of the 3D analysis methodology of the point cloud through different reference shapes. In general terms, the construction is in good condition, so the discrepancies between real construction and the shapes of reference are small, with some exceptions. Nevertheless, the different approximations used allowed us to identify some relevant features, such as the variability of the form of rib vaults, and the influence of the criteria used in the definition and location of reference forms.

Keywords: Terrestrial laser scanner, geometrical assessment, gothic, vaults, Cathedral of Tortosa The development of massive data captures techniques (MDC) in recent years, such as the Terrestrial laser Scanner (TLS), raises the possibility of developing new assessment procedures for architectural heritage. The 3D models that it is able to obtain is a great potential tool, both for conservation purposes and for historical and architectural studies. The paper proposes a simple, non-invasive methodology for the assessment of masonry vaults from point clouds which makes it possible to obtain relevant data about the formal anomalies. The methodology is tested in Tortosa’s Gothic Cathedral’s vaults, where the geometrical differences between vaults, a priori equal, are identified and related with the partially known construction phases. The procedure can be easily used on any other vaulted construction of any kind, but is especially useful to deal with the complex geometry of Gothic masonry vaults.