S U S T A I N A B L E     T E C H N O L O G Y     E D U C A T I O N     P R O J E C T
home  |  about Practical Action  |  contact us  |  site map  | 
The materials on this site are no longer being updated. For Practical Action's main school site go to www.practicalaction.org/schools

Designing a water-balanced railway

The computer-controlled system

A computer process controlled by the railway operator helps to ensure that the cliff railway is safe and efficient.

The computer compares the weight of the top and bottom carriages and calculates how much water needs to be added to the tank under the top carriage to make it heavier than the bottom carriage. If there are a lot more passengers going down than up, only a little water is needed.

Once the amount of water has been calculated, a valve opens to release water into the top tank from a lake behind the top station. When enough water has flowed through, the valve closes. The railway operator releases the braking system and the top carriage moves down.

The carriage speed is controlled by the speed at which the cable drum turns. As it turns, it operates a pump. If the carriage moves too fast (more than 0.7 metres per second!), the pump automatically slows it down.



print this page back to top
Practical Action - Technology challenging povertyEuropean Commission - Department for International Development

S U S T A I N A B L E     T E C H N O L O G Y     E D U C A T I O N     P R O J E C T