Typical of the Central Andino, here is a double switchback. The engine stays coupled and pushes or retains its train backwards on the intermediate level. Thus this train is going away from the photographer, going down the grade.
It might seem that passing the entire double switchback is slow, and indeed it takes a bit of time. But in reality, given the amount of work required and the precautions, it goes quite fast. Systematic implementation of a careful procedure has entirely removed the risks of derailing. The FCCA employees are truly impressive when implementing it. They are the “switchback experts”. It is fascinating to look them doing their work.
Now that derailing accidents is almost a thing of the past, the other types of incidents that are now the most frequent ones are the rock slides. They happen quite often during the rainy season (January-March). The FCCA remains “the most difficult railroad in the world” according to Brian Fawcett's classic book “Railroads of the Andes".