Two GE Boxcab electric locomotive with Soquimich nitrate train from Maria Elena - Barriles, downhill to SQM private seaport in Tocopilla circulating throughout the Barriles gorge with maximum slope - gradeability of 4.1% in Quillagua. The legendary GE BoxCab of the nitrate railways built by General Electric (April 1927) in Schenectady, New York. 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 locomotive 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.