Gravity railroad

A gravity railroad (American English) or gravity railway (British English) is a railroad on a slope that allow cars carrying minerals or passengers to coast down the slope by the force of gravity alone. The speed of the cars is controlled by a braking mechanism on one or more cars on the train. The cars are then hauled back up the slope using animal power or a stationary engine and a cable, a chain or one or more wide, flat iron bands. A much later example in California used standard gauge steam engines to pull gravity cars back to the summit of Mt. Tamalpais.