Cumbre pass horseshoe curve. The Cumbre Pass is a by pass line (that avoids going through Antofagasta city) and connection between large copper mining (Chuquicamata, Codelco Calama, Radomiro Tomic, Spence BHP, Sierra Gorda SCM, others) and port of Mejillones, in the Atacama desert, second region of Chile. The line is characterized by the difficulty of their route, it must reach a great height in a few kilometers for which the train travels through multiple curves and steep inclines of ascent and descent.