New SNSF project on medieval stone arch bridges

Following the significant research projects «Development of the wide-span timber roof truss in Northern and Central Switzerland 1600–1850» (2017–2021) and «The Basilica of Sant' Antonio at Padua - Deciphering the building history of a landmark pilgrimage church» (2019–2023), the Swiss National Science Funds (SNSF) has now granted funding for a third major project «The medieval masonry bridge: Towards a construction history of arch bridges built before 1550» (2022–2026), to professor Stefan M. Holzer (Chair of Building Archeology and Construction History, D-ARCH).

The new project is dedicated to Europe’s remaining medieval stone arch bridges. Surprisingly, this important corpus of medieval constructions has received very little attention by building archeology so far, although the complexity and importance of bridge projects was comparable to cathedral building, and bridges attract great interest by the general public. Establishing a permanent stone arch bridge posed a serious financial and technical challenge to medieval communities, tasks ranging from stone quarrying and stoneworking, laying the foundations in the riverbed, to the final easing of the centring under the completed arches. On-site building archeology is the most promising approach to untangle the bridges’ building and repair history, since archival sources (although abundant) typically provide very little technical detail. In the project, detailed geometrical surveys of the bridges will be created by means of advanced technologies like laser scanning, structure-from-motion photogrammetry employing drone-mounted or cable-car-suspended cameras, as well as automated feature extraction. Precise surveys permit to correlate findings and traces and to reconstruct details of the design and construction procedures. Contextualization of the individual monuments will be achieved by focusing on some particularly dense clusters of preserved bridges, notably, in Southwestern France and Central Italy.