Traffic Q&A: Are the sound-absorbing panels on the new Tacoma Narrows bridge gone?

Q: Whatever happened to those sound-dampening panels the state installed on the new Tacoma Narrows bridge to reduce the noise made by cars driving over the expansion joints? It looks like they’re all gone. — Karen P., Gig Harbor

A: She’s right, and we’re not saying that just because Karen P. is our boss, Executive Editor Karen Peterson.

The panels are, in the immortal words of the Violent Femmes, gone, daddy, gone.

So what happened to them?

We went to Claudia Bingham Baker for answers. She’s the queen of communications for the state Department of Transportation’s Olympic Region.

Said Bingham Baker: “We’ve had trouble keeping them affixed to the walls, so the decision was made to proactively remove them so they would not fall into traffic and become a hazard.

“At present, we have no plans to replace them.”

Thus ends eight years of futility.

Some of you might recall that people who live near the bridge complained not long after it opened in 2007 about an annoying noise issuing from the expansion joints at either end of the span each time a car drove across them.

It variously was described as a “clunk” or a “zipper noise.”

Some folks said it was ruining their quality of life.

The state responded in 2008 by erecting walls near the joints and covering those walls with panels made of a material called SoundSorb. The special aerated concrete was supposed to blunt the noise.

The project cost about $878,000, according to a 41-page report produced by Transportation Department in 2011 titled, “Expansion Joint Noise Reduction on the New Tacoma Narrows Bridge.”

Trouble was that the adhesive attaching the panels to the walls kept failing.

The state tried various fixes over the years, including reattaching 50 new tiles in 2014 with epoxy and rods.

No dice.

It finally decided to pull the plug completely about six months ago, according to neighbors, although the walls remain.

Larry Bielstein, who lives near the bridge on the Gig Harbor side, said he didn’t really notice a difference in the noise with or without the tiles. It’s always been bad, he told us last month.

“We very seldom even use our deck anymore,” Bielstein said.

The state’s analysis found that overall noise was not reduced but back the the panels were in place “comparisons of measurements by frequency suggest that the project effectively reduced low frequency noise from the expansion joint in many locations.

“Again, the low-frequency noise was the source of complaints. The measured results also show a reduction of the high-frequency sound that may have also contributed to public annoyance.”

We asked Bingham Baker whether anybody’s complained since the SoundSorb panels were taken down once and for all.

“Nope,” she said, “but I expect they will start if you write about it.”


Adam Lynn: 253-597-8644, @TNTAdam