Light Bridge Unveiling by ETC: Illuminating Vision Realized
In the heart of Portland, Oregon, the Tilikum Crossing, Bridge of the People, has become a beacon of modern engineering and design. Opened in 2015, this cable-stayed bridge is unique as it carries light rail, buses, streetcars, cyclists, and pedestrians, but not private cars[1]. One of its most striking features is its dynamic lighting system, which responds to the conditions of the Willamette River and enhances the bridge's aesthetic appeal.
The lighting system, designed by Anna Murch and Reyes Engineering of Portland, is powered by LED technology and programmable control[2]. While it does not directly sense river flow or temperature, its programming can be set to reflect data from river gauges or seasonal trends[3]. For instance, the lighting might shift its colours and intensity based on the time of year, weather conditions, or community events, rather than being triggered by specific, immediate changes in the river.
The system includes 178 ETC Selador Desire D40 XTIs and numerous DMX opto-splitters in outdoor housings[4]. During the construction phase, the D40 spotlights on the bridge were focused using a telescope during the day, as night-time construction work was prohibited[5]. The telescope targeted each spotlight at specific points on the bridge, ensuring a uniform and captivating illumination.
A secondary colour pattern on the towers and suspension cables of the bridge represents the water level[6]. The base colour of the lighting is determined by the water temperature, and the timing of colour and intensity changes is influenced by the strength of the current[7]. This dynamic response to the river conditions, combined with the secondary colour pattern, creates a visually engaging spectacle both day and night.
More than 4.5km of cabling was used to wire together the lighting system for the bridge[8]. The data for the lighting system comes from the US Geological Survey[9]. The bridge, standing at 55 meters tall, is designed by San Francisco architects Donald McDonald[10].
In conclusion, the dynamic lighting system on Tilikum Crossing is designed to foster a sense of connection with the Willamette River and the cityscape, but its response to river conditions is largely symbolic and scheduled rather than directly tied to real-time river data[3]. Despite this, the system's innovative design and responsive lighting make it a standout feature of Portland's skyline.
References: 1. [Tilikum Crossing, Bridge of the People](https://en.wikipedia.org/wiki/Tilikum_Crossing,_Bridge_of_the_People) 2. [Reyes Engineering](https://reyesengineering.com/) 3. [Tilikum Crossing Lighting Design](https://theurbanist.org/2015/09/21/tilikum-crossing-bridge-of-the-people-lighting-design/) 4. [HL Stears Inc](http://www.hlstears.com/) 5. [ETC Selador Desire](https://www.etcconnect.com/products/led/selador-desire/spot-lights/d40-xti) 6. [Tilikum Crossing Lighting Patterns](https://www.portlandoregon.gov/transportation/69833) 7. [Tilikum Crossing Lighting Control](https://www.portlandoregon.gov/transportation/article/69832) 8. [Tilikum Crossing Lighting Installation](https://www.portlandoregon.gov/transportation/article/69831) 9. [US Geological Survey](https://www.usgs.gov/) 10. [Donald McDonald Architects](https://www.dmac.com/)
The dynamic lighting system, powered by LED technology and programmable control, highlights the Tilikum Crossing Bridge of the People, decorated with smart-home devices such as the ETC Selador Desire gadgets and DMX opto-splitters. This system, designed by Anna Murch and Reyes Engineering, symbolically responds to river conditions, making it a unique and technologically advanced addition to Portland's urban landscape.
