Anyone familiar with Sydney’s Circular Quay has heard the trains rolling in and out of the elevated Circular Quay Station. From underneath the track, the trains cannot be seen but they can be heard; the noise and vibration can be felt.

During this month’s Vivid Sydney Light Festival the Sydney’s Arup Lighting team produced the work (B)right On Time, designed to replicate the movement of trains into and out of Circular Quay Station with the use of light.

We used the overhead train line at Circular Quay as the location for the installation to visualise the rail network as one of the interwoven arteries of the City of Sydney – with each train representing the blood flowing through the veins, and the lighting pulsing as a heartbeat that can be felt, thus giving sight to the beat of the life of the city.

The site incorporates approximately 100 metres of public thoroughfare, commencing at George Street and running parallel to Alfred Street to the station precinct of Circular Quay Station.

We designed the lighting system to be synchronous with the trains as they enter and leave the station via sensors mounted to the tracks above. There are many types of sensors available but a laser beam was the most simple and reliable sensor that we tested and therefore we chose go with this method. With RailCorp’s help we located a laser beam break sensor at each end of the platforms. These were mounted on existing structures on the bridge at a height to register when the train passed through, breaking the beam and sending a signal to the dry contact terminals in the control system. This in turn set off the pre-programmed light show.

RailCorp operate a train at approximately every 2-3mins in peak hour, so the frequency of light operation was regular and fairly consistent during these times. As well as being synchronised to suit the trains as they enter and leave the station, the lighting colour changed to reflect the train lines, orange lighting for the Bankstown Line,

purple lighting for the Inner West Line,

green for the Airport and East Hills line

and blue for the South Line.

We had great fun producing this project. Thanks to Vivid and the City of Sydney as well as RailCorp for access, and Inlite and Traxon for supplying the fittings.