A designer revisits her roots to create a new identity for a memorable bridge

By Samantha Schwirck

Ken Burns Bridge

The Ken Burns Bridge between Worcester and Shrewsbury can be viewed by motorists, boaters, swimmers and residents around the lake. Photos by Matthew Houston

As a Worcester, MA, native, Faith Baum, now a principal at New Jersey-based Illumination Arts, is well acquainted with the Kenneth F. Burns Memorial Bridge. Named for a police chief who founded and coached the crew program at a local high school, the structure connects Baum’s hometown with Shrewsbury, MA, over a bustling lake known for its rowing and sailing regattas. Baum recalls crossing the span countless times—to take a boat ride at White City Amusement Park at age five, to see a film at the cinema that replaced the amusement park, and eventually to work her first job at a music and dance venue.

While Baum’s local savvy came in handy for creating a lighting plan that reflects the community’s character, it wasn’t the reason Illumination Arts was chosen for the job. “It was a coincidence,” says Baum, who brought decades of experience illuminating bridges around the country to a project with multiple stakeholders, including officials and citizens from Shrewsbury and Worcester, the Massachusetts Department of Transportation, and a design team consisting of architect Bridgescape, bridge engineer Tran-Systems, contractor The Middlesex Corporation, and engineering firms T.Y. Lin International and Fay Spofford Thorndike (now Stantec).

When Bridgescape invited Illumination Arts to collaborate on the replacement bridge in 2011, public discussions about the structural design were complete. Elegant, curved arches would recall the original bridge’s aesthetic, while four 50-ft tall sail-like structures, two on each end of the bridge, would serve as gateways to each town and nighttime icons for the site.

Discussions about the lighting design, however, were just beginning. In fact, it would be another year before the final design phase would commence, during which time Illumination Arts abandoned its original proposal, consisting of simple lines of light tracing the arches and overlook supports, and static blue and green in-grade uplights illuminating the sail structures. “As we moved into the details of the final design, we discovered that there was little concealed space for the wiring and drivers needed for the selected solutions. The owner also expressed a desire to include color-changing lighting, first just at the sails and eventually along the entire structure,” Baum explains. “This change in mindset was our biggest challenge—we needed to let go of the design we’d embraced to explore a more dynamic and visible design solution.”

 

Ken Burns Bridge

To ensure lighting reveals the overall form of each sail, designers determined location, size and spacing of the spanning cables.

FRESH START
Letting the original design go, albeit reluctantly, made way for the color-changing solution that debuted in 2015. Color-changing was just one of the considerations for the new lighting—weather, vibration, light pollution and driver needs were additional factors in fixture selection and placement.

For the massive sails at each end of the bridge, Illumination Arts was also responsible for the location, size and spacing of their stainless-steel spanning cables, which work in tandem with lighting so the structures look transparent during the day but are visible from all angles at night. “The sails had been designed structurally, but the specifics of the cable dimensions and spacing had not,” Baum explains. “We strongly recommended a mock-up be built, but neither time nor money was available to do that. In the end, we ran calculations in AGI32, looking at the spacing and diameter of cables to figure out what would work best.”

Eleven linear 4-ft long RGB LED fixtures mounted vertically along each sail’s “mast”—for a total of 44 fixtures across all four sails—transform the structures into the dynamic welcome signs the towns envisioned. Aiming angles for each fixture were predetermined to ensure uniform light distribution that reveals the overall form of each sail.

Color-changing fixtures also illuminate the bridge’s underside, visible from lakefront homes, beaches and boats. To ensure the arches are evenly lit, designers selected RGB LED floodlights with precise optics and calculated the aiming angles to be used by the contractor when installing the fixtures. The floodlights are mounted at the base of each arch and include steel fins for protection from boats and vandals.

A custom user interface and pre-programmed scenes enable the owner to change the arch and sail lighting for holidays or special events. “The structure is painted bright blue so we anticipated some colors wouldn’t look as good as others,” Baum adds, “but we were pleasantly surprised to see that all colors are equally vibrant.”

Still, Baum might have tweaked the design if more advanced products had been available. “By the time a bridge project, or any project, is completed, a generation or more of LED products has come and gone,” she says. “If I had it to do differently, I’d use RGBW or RGBA LED fixtures with a tighter beam spread to try to concentrate more of the light on the undersides of the arches.”

Ken Burns Bridge

Color changing floodlights enable static or kinetic programs for holidays and occasions.

Fast Facts

  • Transparent sail structures at each end of the bridge become colorful gateways at night.
  • Steel fins on arch floodlights protect against boats and vandals.
  • The pedestrian walkway is clearly defined by 4000K linear LEDs that contrast HPS roadway lighting.

LOCAL LOVE
The color-changing fixtures are complemented by white, linear LED handrail lighting along the pedestrian walkway, designed to encourage foot traffic and sightseeing along the bridge. The fixtures do not obstruct views from overlooks and benches, and a color temperature of 4000K clearly delineates the path by cutting through the orange-yellow of the high-pressure sodium roadway lighting. Late at night, the lights are dimmed to reduce energy consumption and minimize visual disruptions to lakeside residents.

Despite one scrapped design, zero mock-ups, unpredictable paint colors and the introduction of new technology, the final iteration exceeded expectations and received a positive response from the community—of which Baum remains a proud member, even if from afar: “It’s fun to have the personal connection to Worcester and see friends of friends on Facebook post photos with glowing remarks about how beautiful it is and how much fun it is to photograph.”

Contributor(s)

Samantha Schwirck

Samantha Schwirck

Samantha Schwirck is senior associate editor for... Continue Reading »