across the Andes by train

The bridge over the Cacheuta, 40 km from Mendoza, Argentina

The Trans-Andine railway (Ferrocarril Trasandino) was a metre-gauge combined rack (Abt system) and adhesion railway which operated between Mendoza in Argentina across the Andes mountain range via the Uspallata Pass to Santa Rosa de Los Andes in Chile, a distance of 248 km. It completed a 1,408 km rail link between the Argentine capital of Buenos Aires with the Chilean port of Valparaiso, and provided the first rail route linking the southern Pacific and Atlantic Oceans.  At Las Cuevas there was the summit Cumbre Tunnel of 3.2 km (2 miles). The highest point of Los Caracoles (3,176 metres) was at the other end of this tunnel.

Passenger services from Buenos Aires to Valparaiso took about 36 hours in total, including changes of train in Mendoza and Los Andes, required because of the break-of-gauge at these points. Previously the 5,630 km journey by sea from Buenos Aires to Valparaiso, around Cape Horn, had taken eleven days. The Chilean Transandine railway was originally worked by Kitson-Meyer 0-8-6-0s rack and adhesion locomotives, two examples of which survive in Chile. The line was electrified in 1927 with Swiss-built electric locomotives, using 3 kV DC.

An electrically hauled freight train at Las Cuevas in 1973.

undated postcard of Los Caracoles, Chile

The railway has been out of service since 1984, and has been partly dismantled. In 2006, both the Argentine and Chilean governments agreed to refurbish the railway and make it functional by the the line's centennial in 2010, at an estimated total cost of US$460 million. But little progress has been made, although travellers in April 2008 saw some activity on the Chilean side, including ballast renewal at the Aconcagua power station and labourers in action at Santa Rosa de Los Andes.