ALCo traction x 4, train loaded with various chemicals #50.553, and empty freight train (timber) #50.093 both of FEPASA from Nueva Aldea and Talcahuano, bordering the Pacific Ocean with destination Horcones, in Arauco city. The area of picture is known as "twins tunnels" ("Túneles Gemelos") as there are 2 tunnels exactly alike and separated by a few meters (behind the photographer in the picture). See this picture, train in the opposite direction: http://www.railpictures.net/photo/515208