206 x 148 mm. A view looking down on a curving section of track climbing the side of a steep hill on the Laurenco Marques line near Waterval Onder. The tunnel in the sheer cliff face can be seen in the background. The line here features a central rack meshed into cogs on the underside of the locomotive to provide purchase on the steep gradient. The only rack railway in South Africa, it became obsolete with the advent of more powerful engines.