Built by General Electric (April 1927) in Schenectady, New York, the legendarys GE BoxCab of the nitrate railways, are detainees with trainload in Reverso passing loop, in the background the bay of Tocopilla (244 meters from the position of the photographer to the sea level). 7 locomotives were constructed (601-607), of which do not exist anymore the 602 and 605. Each locomotive was assigned a female name, in honor of wives of the managers of the former nitrate company. The leading locomotive is No. 601, named "Andrea". The second machine is No. 603, called "Mario Beroiza", this is the exception because the locomotive was christened with that name in honor of a railway worker who died in a train accident.