The engineering design of the Tua rail track : evidence from the archives

Abstract

This paper intends to give a detailed overview of the different phases of the Tua line focused on the changes in the longitudinal and transversal outline and on the definition of the project of special structures (tunnels, bridges, aqueducts and stone walls). For this, a detailed investigation was carried on the archives of REFER, the company in charge of the management of the infrastructure of the national Portuguese railways. The Tua line fit the Nacional railways plan, defining the connection between the Douro region in Foz Tua and Mirandela in a first phase (1987) and Bragança in a second phase (1906). The construction of the Tua line aimed at flowing the products derived from the Douro region. Its construction was not an easy process, mainly in the first 20km due to the severe relief, composed of narrow valleys with impressive ravines, precipices and waterfalls. This difficulty was also associated to the lack of accessibilities and to the scarce technological resources, resulting in several accidents and human losses and to a huge physical effort. The first studies related with the Tua line date back to 1880 and the last ones are from 1883. However, due to changes imposed by the in situ geomorphological conditions, amendments to the project were made and presented in 1885. Several changes are identified between the previous studies, the project and rectified project.