View from the Aare Bridge towards the south portal of the Hauenstein Base Tunnel

Tripolis, construction site and workers’ housing at the south portal of the Hauenstein Base Tunnel

Hauenstein tunnel, north portal, workers with concrete mixer

Workers in front of the south portal of the Hauenstein Base Tunnel

Workers in front of the south portal of the Hauenstein Base Tunnel

Triangular junction at Olten with the rail lines to Aarau, through the Hauenstein tunnel to Basel, over the old Hauenstein line to Sissach and into Olten station, 2010. In the centre the Wisenberg, Jura mountain range

Gotthard: Biaschina, Pianotondo Viaduct, lower entrance to the Travi spiral tunnel

In the Gotthard tunnel, safety doors must withstand air pressures of up to seven tonnes

In the Gotthard tunnel, safety doors must withstand air pressures of up to seven tonnes

The last of the 380,000 sleepers in the Gotthard Base Tunnel are coloured gold.