The Argentine Tren A Las Nubes, in English: Train towards the clouds, ranks among the highest and most spectacular railway routes in the world. The route features numerous bridges, tunnels, kick turns and turning loops and is considered a masterpiece of engineering. The highest station is located at an altitude of 4,188 metres.
Argentina is the eighth largest state on earth and the second biggest state of South America. With an area of about 2,800,000 km² Argentina is bigger than the European states of Belgium, Germany, France, Greece, Great Britain, Italy, Luxemburg, The Netherlands, Norway, Austria, Portugal, Switzerland and Spain together. However, while Europe counts an average of 65 inhabitants per km², in Argentina there are just 15 inhabitants per km². In the northwestern province of Salta, where the railway route of the Tren A Las Nubes is located, there are even only eight inhabitants per km².
Salta is the capital of the eponymous province of Salta at the eastern promontories of the Andes, the longest mountain range in the world. It was founded in the 16th century by the Spanish conqueror Hernando De Lerma. Even today, many buildings in Salta are of Spanish architecture. In the course of time, more and more European immigrants settled there. Two important industry sectors thrived: agriculture and mining. The Andes hold huge amounts of raw materials such as silver and nitre, which have been mined for centuries. In order to be able to sell the agricultural products and the raw materials all over the world, a connection to a large port had to be established.
Antofagasta is a Chilean city near the Pacific Ocean, the port of which still is an important trans-shipment center for copper, steel and nitre. The construction works for the approximately 780 kilometres long railway route between the Argentine city of Salta and the Chilean port of Antofagasta started in 1922. An enormous task. After all, the trains were supposed to master huge differences in altitude. From Salta at an altitude of 1,200 metres, over La Polvorilla at an altitude of 4,200 metres to Antofagasta at sea level. After a construction time of 27 years, the route was finalised. In order to enable the trains to travel without gearwheel technology, 44 bridges, 21 tunnels, two kick turns and two turning loops were built.
The railway traffic experienced a real heyday throughout Argentina until the 1950s. At that time, the railway network of the South American country was well established. Since the 1960s, more and more railway lines have been decommissioned for the benefit of road traffic. The once modern routes decayed slowly. In this way, also the railway route between Salta and Antofagasta lost their economic importance. What is left is the beauty of the mountain landscape along the route. And that should by no means be withheld from the tourists.
In 1970, the tourist train Tren A Las Nubes commenced operations. The original route led from the General Belgrano train station in Salta over the small city of San Antonio de los Cobres to the La Polvorilla viaduct and back to Salta. The La Polvorilla viaduct was built at an altitude of 4,188 metres using 1,600 tonnes of steel. It covers a length of 224 metres and features a height of 63 metres. In the way from Salta to the viaduct, the Tren A Las Nubes crossed 29 bridges, 21 tunnels, 13 viaducts, two turning loops, two kick turns and 21 railway stations. The train took about 17 hours for the trip from Salta to La Polvorilla and back, which had a total distance of 434 kilometres. Since the average speed was 25 kph, the passengers could well observe the beautiful landscape. Green meadow valleys, wild cactus landscapes, the arid Puna highlands and glaciers with altitudes of slightly below 6,000 metres.
After several operator changes and the gradual deterioration because of lacking maintenance due to the decreasing importance of the route, the technical breakdowns became more frequent. The worst incident took place in 2005. The train stopped on the Polvorilla viaduct and the passengers had to be evacuated at sub-zero temperatures. It is for this reason that the former operator was withdrawn the license and that the operations were stopped for years. Despite some repairs, the train derailed again in the following years so that the operations were stopped over and over again. Until 2016.
Today, the Tren A Las Nubes only travels between the city of San Antonio de los Cobres and the La Polvorilla viaduct. The distance measures 21 kilometres. The train spans two passenger wagons, one buffet car, one dining car and one serve wagon for 170 passengers. This ensemble is pulled by a diesel electric locomotive with around 2,500 hp. The passengers travel the rest of the original route from the provincial capital of Salta to the small city of San Antonio de los Cobres in coaches. Compared with Central European conditions, the special equipment of the trains is rather unusual. There is always medical staff and a compartment with a small infirmary on board. No wonder, since many passengers are not used to such altitudes and the very thin mountain air. Therefore, they often need oxygen and other medication against the symptoms that occur in high altitudes. Once they arrive at the top, everything is okay again. The imposing view over the summits of the Andes definitely compensates for any inconvenience!