Archivo:El. Teniente smelter and Sewell townsite, Chile ... Text Appearing After Image: Sewell (El Teniente Copper Mines) near Rancagua. MINING 179 way line to Rancagua, at a spot where the junction ofthe Coya and a canal from the Cachapoal River formsa waterfall of 422 feet, yielding hydraulic power suffi-cient for the generation of 40,cxx5 H.P.