About this journey

Domodossola station, which became an international facility on 1 June 1906 with the opening of the Simplon Tunnel and the Brig–Domodossola railway, is also a break-of-gauge junction where standard-gauge lines to Milan, Brig and Novara meet a metre-gauge line to Locarno. At the station, the electrification system changes from Italy's 3,000 volts DC to the Swiss 15,000 volts AC 16.7 Hz, marking the boundary between two national railway standards before the train enters the Alps.

Northward from Domodossola, the route passes through nine tunnels before the Simplon Tunnel proper, among them the 2,966-metre Varzo Tunnel, which is built as a spiral to gain the necessary height. Train services on this cross-border section are jointly operated by BLS AG and Swiss Federal Railways, forming part of an international link between the Italian- and German-speaking parts of Switzerland. Beyond Brig the journey continues over the Lötschberg line toward Bern, with the BLS NINA and MIKA units handling the Swiss legs of the run.

Bern railway station, opened progressively between 1858 and 1860, is the terminus for BLS services arriving from Brig and Domodossola. The journey as a whole moves from an Alpine valley junction shaped by nineteenth-century Italian rail expansion to one of Switzerland's principal federal city stations, crossing a voltage boundary, a spiral tunnel, and the main ridge of the Alps along the way.