The underside of bridges are mostly neglected forgotten dark spaces. Train bridge traffic produces useful vibration. This vibration can be used to create a fluid light installation.

working title :

Good Vibrations

project description :

Off the Grid sustainable public light work .


Trains that run on an overhead rail track produce vibrations that can be used to trigger low energy hi-power LED lamps.

By placing at regular intervals small vibration sensors I intend to make a light installation that follows the path of a train on the underside of the bridge as the train moves along the rail track.

Simple efficient wind & solar techniques will supply Good Vibrations with all its power. The wind generators will be placed so that they can harvest the wind created by passing trains as well as naturally occuring wind.

During the day harvested energy is stored in batteries. As dusk falls photosensors and timers switch power to LED/piezo vibration units.

Sensors and LED/piezo vibration units will be placed every 2mtrs, solar wind harvestors every 100mtrs

The final budget plan is dependent on the length of bridge used and also the type of bridge used.

Budget will vary depending on site location. Local lighting conditions will have to be considered.

Install time depending on site and accessibilty between 5 and 7 days.

For this example a distance of 100mtrs was considered and shows material costs only.

vibration sensors per unit 20 € x 50 pcs for 100mtr
1000 €
solar power 200w x 1
wind power 200w x 1
LED 10w lamps per unit 25 € x 50 pcs
1250 €
total per 100mtrs


  animated mock up of proposal  

proofs of concept -- 10 units with 1w LED followed by 2 units with 10w LED

for the temporary proof of concept installation vibration/LED units were fixed with strong magnets. Units were not tuned to bridge vibration due to lack accessibility. Tuning vibration sensors will make ON/OFF timing more precise. On site tests were done with10units with 1w LEDs and then 2 units with much brighter 10w LEDs.Tests proved very successful.

     acknowledgement to Forrest M. Mims for Vibration Circuit.
  1w LED units  
  10w LED unit  

conclusions :

this project is adaptable and can be realised with basic install techniques to proposed structures with co-operation from local authorities. Recent tests on another Off the Grid project, Island, have shown that the Off the Grid techniques employed are reliable and effective. The installation will be tuned specifically to its site location and time of year. Using neodynium magnets it is possible to install LED/vibration units quickly and safely with minumum intrusion to exisiting structure. Small safety cables can easily be clamped to structure for added security.