The drive to West Seattle looks a little brighter this winter now that City Light has completed the upgrade of the streetlights on the high bridge from high pressure sodium luminaries to energy-efficient LED fixtures.
City Light’s contractor Potelco replaced 145 light fixtures on the bridge between Dec. 4 and 5, with a little help from traffic controllers from the Seattle Department of Transportation. The work was done without closing the bridge, though one lane was closed to make room for the service vehicles.
Workers replaced the existing high pressure sodium lights, which draw 290 watts, with light-emitting diode luminaires. The LED fixtures use only 135 watts, or an energy savings of almost 50 percent. The solid-state LEDs won’t need to be replaced for 15 years. By comparison, the sodium fixtures need replacement every 12 to 18 months, partly because the vibration from cars on the bridge can damage them.
Stephen Crume, Joint Use & Streetlight Engineering manager at City Light, said City Light took advantage of a lane closure already planned by SDOT to schedule the streetlight work.
“We used their traffic control to make space, and finished the east-bound side of the bridge in one day,” Crume said. “We paid their traffic control folks for the following day, and managed to finish the project with minimal impact on drivers.”
On Dec. 15, 90 LED fixtures were installed on the exit and entrance ramps to the bridge, completing the West Seattle Bridge conversion project.
The project is the most visible part so far of the effort to upgrade all the streetlights on arterial roads with LEDs. Work was recently completed in the White Center business district, the Cascade neighborhood and Meridian Avenue North in Shoreline. Currently crews are working along streets between Denny Way and 65th Street.
This fall, City Light completed the conversion of 41,000 residential streetlights to LEDs. The conversion is expected to save the City of Seattle up $2.4 million in annual energy and maintenance costs.