An old lady still at work: this unit and its 4 sisters are the only GE Box Cab survivors in regular service today. Built in the mid and late 1920's they are among the oldest electric engines still in service in the world. The unit 604 aka "Viviana" was built in 1926. It works on the 27km-long 1067mm gauge (3'6") Tocopilla - Barriles section as the electrics only run on the 4.1% grade between sea level and the plateau. In Barriles, at the altitude of 995m, diesels take care of the trains up to the Maria Elena mine and back. The trains are empty when climbing, and full of nitrate when going down. The GE Box Cabs will soon be replaced by brand new electrics currently under construction in Chile. The first new unit is already in service. The picture shows a train during the ascent from Tocopilla. The city, its harbour and the Pacific Ocean can be seen in the background.