An eerie whistle loud enough to be heard from up to five miles away has been rolling off of the Golden Gate Bridge for over a year now, disquieting San Francisco residents every time a strong breeze blew through the newly installed sidewalk railings along the bike path. Now, the sound, a hollow hum that’s been described from “pleasant” all the way up to “deafening” (especially if you’re on the bridge at the time), will finally be fixed.
Videos of the ethereal noise from confused Californians went viral in June of 2020, but after some digging, it was discovered that the noise was intentional—or at least not unknown to engineers before the railings’ installation.
“The Golden Gate Bridge has started to sing,” Paolo Cosulich-Schwartz, public affairs manager at the Golden Gate Bridge, told KQED. “The new musical tones coming from the bridge are a known and inevitable phenomenon that stem from our wind retrofit during very high winds.”
The new railings are integral to making the bridge more aerodynamic and reducing wind-induced strain on the western side, but the noise apparently isn’t required. The Golden Gate Bridge, Highway and Transportation District, a special district that manages the bridge itself and Golden Gate Transit and Golden Gate Ferry, has announced a design fix it plans to implement in 2022.
The solution is quite simple, if seemingly labor-intensive—affixing 1/16”-thick aluminum clips to the top and bottom of each of the 12,000 affected slats, with a length of 1/16”-thick vibration dampening rubber tubing between them. The clips will then be painted orange to minimize their visual impact. By altering the profile of each slat so that air can’t pass through them uninterrupted, it’s estimated the volume of the ghostly whistling will be cut down by 75 percent, a huge relief to the surrounding neighborhoods.
Intended to be cost-effective while not compromising the bridge’s ability to withstand sustained winds of over 100-miles-per-hour, the fix will cost $450,000 and will be completed sometime in late 2022. The plan was brought before the Bridge District’s Board of Directors on December 17 and approved in a unanimous vote.