The construction of the railway started in 1921, to connect the North of Argentina with Chile across the Andes, and to serve the borax mines of the area. The viaduct La Polvorilla, the highest of the line, was finished on. The Chilean track was inaugurated in 1947 and the complete railway on. The route was designed by American engineer Richard Fontaine Maury, after whom one of the stations has been named.
Origin of the name "Huaytiquina"
The word "Huaytiquina" is the nickname of the railway. It refers to an ancient Andeanmountain pass between Argentina and Chile, located just in north of Socompa and projected as line terminus. In 1923, after a Chilean request whose rail line arrived close to Socompa, the original project was abandoned and the Argentine route diverted to the current one.
Route
The line crosses the north-western side of Salta Province, serving the suburban towns around Salta of Cerrillos, Rosario de Lerma and Campo Quijano, following part of the course of the Lerma Valley. It counts two zig zags, at El Alisal and Chorrillos, and two spiral loops between Tacuara and Diego de Almagro. Entering the plateau of Meseta, the railway passes near Santa Rosa de Tastil and the Pre-Incaarchaeological site of Tastil. It serves the town of San Antonio de los Cobres, in the middle of the Puna de Atacama, nearby copper mines. After the viaduct La Polvorilla, highest point of the line, the railway runs on the borders of Jujuy Province at Olacapato and, between Tolar Grande and Caipe, it crosses in the middle a dry lake named Salar de Arizaro. The station of Socompa, named after the Andean vulcan, is a bi-national station located between the Argentinian-Chilean frontier line. Entering the Chilean territory, the rest of the line crosses the municipal territory of Antofagasta, located in the homonymous province and region. Varillas and Augusta Victoria have a short industrial rail branches, the one of Varillas serving Escondida mine. At Palestina station, the line crosses the junction railway Baquedano-Aguas Blancas, named FF.CC. Longitudinal, linking the lines Antofagasta-La Paz and Antofagasta-Copiapó. Descending the western slopes of the Andes and the Atacama Desert, the "Huayitquina" reaches the industrial complex and village of La Negra and, after 22 km, the Pacific Ocean in the port city of Antofagasta.
Train services
Due to a presence of mineral deposits in the Atacama area, most traffic on the line consists of freight trains transporting minerals such as lithium carbonate, borax, butane, pearlite, salt, ulexite, and brine. The most famous service is the sightseeing Tren a las Nubes, running between Salta and La Polvorilla. Nowadays, apart from some suburban trains running from Salta to Campo Quijano, the Tren a las Nubes is the only passenger train serving the line, after the cancellation of the Tren Mixto Salta-Socompa, that once linked Socompa with Tucumán and Buenos Aires, via Córdoba and Rosario. The Chilean part of the line, also served only by freight trains, was the site of a proposed commuter rail line on the route running through Antofagasta.
