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Hidden Agenda

May 27, 2021

This bridge doesn’t just transport people from point A to point B. It also aids in the movement of what’s above

By Samantha Schwirck

It’s true. Beauty really is only skin deep. And lighting design is no exception. Designed by HLB Lighting Design (New York City), the new Samuel De Champlain Bridge in Montreal shows how architectural bridge lighting can also serve a hidden purpose by protecting native wildlife and building community during trying times.

As part of a design/build team, HLB spent more than four years developing the lighting plan for the bridge, which opened to traffic in the summer of 2019. Spanning almost 3.4 kilometers (2.1 miles) across the St. Lawrence River, the design utilizes more than 7,000 luminaires and 45 universes of DMX control to realize a lighting display that reflects the thriving city of Montreal and its diverse population, while also respecting the area’s native wildlife.

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“The goal was to give Montreal a world-class cable-stayed bridge with a dynamic nighttime presence,” says Kenneth Douglas of HLB, who worked with colleague Elizabeth Johnson to carry out the RFP supplied by the Government of Canada, the project owner. “The lighting system allows the movement of light along the structure’s entire length and up the inner faces of the cable stay tower, all while restricting uplight and limiting skyglow around the structure.”

The design team—which included engineer T.Y. Lin International and Donald McDonald Architects—also had to accommodate one particularly sensitive end user: bird “traffic” overhead. The mission was to protect the bird migration route along the waterway by strategically using colors least likely to distract the wildlife. “Using research [indicating that] the birds are using the moon to navigate, we specified a set of wavelengths that are not as disruptive to them,” Johnson explains.

The project satisfied the need for both a vibrant yet wildlife-friendly design concept using just one fixture family, with the majority of the 7,000 luminaires being Lumenbeam fixtures by Lumenpulse. “The fixtures that create the ribbon of light are hidden behind the structural beam in each bay. The Extra Large version [of the fixture] is up on the tower recessed in niches of the inner face,” Douglas says. “The optics vary over the length of the tower to get the most even light coverage, and all are color changing using RGB LED.”

The luminaires located along the edge girder are mounted close to a structural support beam to conceal them from view, Johnson adds. “They use alternating mounting angles to evenly illuminate the edge girder from top to bottom. The aiming angles and beam spreads are different on the north and south sides of the bridge because the mounting distance from the edge girder differs. Care was taken to accommodate special conditions like drainpipes and expansion joints so although the mounting conditions change the ribbon of light looks consistent along the full length.”

The scale of the project—and mid-project technology developments—added complexity to the design process. “Providing a lighting system that stretched continuously over 3 kilometers and consistently performs the programmed scenes required a robust control system network design,” Johnson explains. “The system started out using traditional DMX distribution connected to a fiber network, but the temperature requirements drove us to try to remove the DMX gateways which were not meeting the minimum temperature required, and instead use network cables to deliver the control signal.

“We were fortunate to have the change in DMX control network technology happening in the middle of our control system design process. With the collaboration of the luminaire manufacturer and the lighting control systems integrator [Barbizon NYC], we were able to design a control system with fewer components that could provide a more reliable control signal in the structure’s environment.”

At the same time, the lighting concept is an ambassador of sorts for Canada, Quebec and Montreal. The initial scenes for the bridge acknowledge their place in the world, with red and white Canadian scenes referencing the nation’s flag, as well as scenes celebrating Quebec using its signature blue and white colors. The Canadian government has also used the bridge as a canvas, illuminating the span in rainbow colors to reflect a message of unity and gratitude for healthcare professionals and other essential workers during the coronavirus pandemic.

At night, the lighting scenes bring the structure to life across the St. Lawrence. “The nighttime image of the bridge has become an icon for Montreal showing up on community and social media posts,” Douglas says. “The bridge has quickly become a landmark and the dynamic lighting allows the Government of Canada to use lighting scenes to create a connection back to the community.”