Ferrovia Alta Valtellina

In 1899 a company was established for the Alta Valtellina Railway (FAV) with the aim of connecting Sondrio with Tirano.

[2] On 1 July 1908, the Tirano-St.Moritz line was activated by the Swiss private company Berninabahn (now part of the Rhaetian Railway) which allowed the connection of the Upper Tellina Valley with the Swiss slopes of the region.

Numbers 1-3 were built by Costruzioni Elettro Meccaniche di Saronno (CEMSA).

In 1967, due to the declining popularity of three-phase traction, the line was de-electrified and operated by diesel-powered trains of type ALn 556 chartered from Ferrovie dello Stato Italiane (FS).

In the mid-1980s, the line was the subject of a larger programme to upgrade the route from Milan for a cost of about 100 billion lire, which involved the activation of Centralized Traffic Control (CTC) between Sondrio and Tirano, with a Central Manager in Colico.