Clifton Rocks Railway in Bristol, England, in 1904 and now

The Clifton Rocks Railway was an underground 137 metre (450 ft) long funicular linking Clifton at the top to Hotwells and Bristol Harbour at the bottom of the Avon Gorge in a tunnel cut through the limestone cliffs.

The gradient was about 45% Propulsion was by the water-balance method, in which the cars of each pair were connected by a cable running around a pulley at the upper station; a large tank on each car was filled with water at the top and the extra weight provided the motive power.

It operated from 1893 to 1934.

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