Tunnel structure

The Ceneri Base Tunnel was excavated entirely by drilling and blasting between 2007 and the start of 2016. The maximum rock overburden is up to 900 metres, the least only a few metres.

Most of the excavation was performed simultaneously in both directions from the intermediate heading at Sigirino. From the portals at Vigana and Vezia, inward drives were excavated to minimise time and costs. Near the portals, only protective construction methods could be used, since work in these areas had to be performed in sensitive environments.

On March 17, 2015, around 400 metres away from the south portal at Vezia, more than 600 miners and project participants followed the first breakthrough of the Ceneri Base Tunnel. In the southbound west tube, breakthrough took place with great accuracy: at two centimetres horizontally and one centimetre vertically, the deviation was extremely small. The final breakthrough to the north took place in the west tube on January 21, 2016.