Els túnels ferroviaris a la collada de Toses

Abstract

At the beginning of the 20th century, and within the train network connecting to France, there was a project to extend the train network Barcelona-Ripoll to Ribes de Freser and from there, crossing the Toses pass, to Puigcerdà in order to finally reach France. To overcome the Toses pass, two tunnels were excavated: a 1.057 m helicoidally tunnel and a 3.904 m rectilinear one. The tunnel of Toses presented significant difficulties, especially at heights ranging 1.700-1.800 m from the entry (at Ribes’ side). Further to the lining initially planned, the stresses generated were greater than the rock’s strength. Thus, to solve the difficulties it was necessary to modify the excavation method, initially the Belgium system, and to coat the tunnel by over excavating the gallery and using linings of up to 3 m wide. Drilling started in September 1911 and ended in February 1919.