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A quest to solve the mysterious “creepy” ham of the Golden Gate Bridge | San Francisco

SSomewhere in the wind tunnel southwest of Ontario, a group of world-leading bridge aerodynamics and acoustics experts are confused by a full-scale model of the Golden Gate Bridge railing.

Experts have been contracted for the past year to solve the mysterious problem of strange humming sounds that emanates from San Francisco’s famous bridge and drives nearby residents into a state of madness.

Sounds that can only be heard on windy days are “ghostly harmonica,” “monk chanting,” and “Wheezing Kazoo“.

The strange cry soon became a legendary piece of San Francisco’s auditory landscape.Amateur detective has Walked around the hills of the city An electronic music producer who tracks the sound source and claims to have mixed it Existential horror soundtrack.

Some fans called it the bridge’s “soothing” song. Others dubbed it as “creepy” or “unbearable.” One woman simply blamed it on “aliens.”

“It sounded like the noise that prison officers could imagine using to torture prisoners,” said an uneasy resident of the social media app Next Door.

However, according to a spokesperson for the bridge, sometime this summer, engineers will announce plans to stop the sound.

Immediately after city residents began complaining about Ham in June 2020, embarrassed bridge officials conducted an investigation. They tracked the sound and used an instrument to measure the vibration of the hum and found that it often emitted a frequency of 440 hertz, which coincided with note A.

As one poster at Nextdoor points out, you can use it to “tune the oboe”.

Ultimately, experts say that the breeze of the city is a set of newly installed bridge railing slats from a slightly off-quilter angle, either slightly north or slightly south of the normal wind from the west. I decided that humming would occur when I hit.

“After a thorough investigation of this phenomenon, we determined that the sound came from a new, more aerodynamic railing on the western sidewalk,” said bridge spokesman Paolo Cosulich-Schwartz. .. “This was part of a modification of the Golden Gate Bridge designed to protect the bridge for future generations by allowing it to withstand sustained strong winds up to 100mph.”

The bridge was temporarily closed three times during its 84-year history due to gusts of 69 to 75 mph. Photo: Jeff Chiu / AP

He said new, thinner railing slats were installed to prevent the bridge from fitting at the same end as Washington’s unlucky Tacomana Rows Bridge, which collapsed in 1940 as the bridge began to vibrate violently in the wind. .. It was built. Nicknamed “Gallopin’Gertie”, the span has become a classic. Engineering class In a way that doesn’t build a bridge.

“So this was a project we had to do,” said Cosulich-Schwartz of the Golden Gate Bridge, a windproof highway and traffic district last year. “Climate change impacts lead to more serious meteorological phenomena, making it even more urgent to complete them as soon as possible.”

According to a 2013 survey by authorities, the maximum sustained wind speed built to withstand the bridge was 69.34 mph. Already, in 1951, 1982 and 1983, gusts blew from 69mph to 75mph and were temporarily closed three times in 84 years of history. However, there was no damage.

As a result, bridge engineers believed that the new thin slats would allow the bridge to withstand a sustained 100 mph wind. This is estimated by research to occur only every 10,000 years. They did not predict that slats would produce such a dissonance in a normal year.

Warren Briar, a veteran science director at the National Weather Service, said 100 mph of sustained winds can only occur in tornadoes, hurricanes, or tropical cyclone conditions. And it’s unknown or unpredictable to hit near San Francisco.

The sound from the bridge, which can only be heard on windy days, is compared to a
The sound from the bridge, which can only be heard on windy days, is compared to a “ghostly harmonica.” Photo: John G Mabanglo / EPA

“It seems very unlikely to me,” said Blier, who admitted that his job was usually to predict the weather seven days in advance, rather than the next 10,000 years. “Hurricane has never hit the coast of Northern California in the history of the state.”

Meanwhile, the bridge engineer is determined to come up with a ham fix.

RWDI, an engineering company one hour west of Toronto, has a full-size model of the 12-foot section of the new railing. A wind tunnel about the size of a conference room in a convention center.. Engineers are exposed to blast waves of varying wind speeds and are testing changes to see if the hum can be muted.Tested by the same company Model of the entire bridge In the early stages, no one seemed to realize that humming would be such a problem.

“We will share more information about possible solutions this summer,” said Cosulich-Schwartz. “We understand that some people who live near the bridge tend to find the bridge painful. We want to be good neighbors. So hopefully we The solution will calm your neighbor’s ears. “

But in this famous city of opinion, not everyone wants to see ham disappear.One local blogger Golden Gate Bridge Ambient Sound Playlist To help listeners on sleepless nights when the sound is missing.

“I like sound,” said Brian Howell, who lives in western San Francisco. Video featuring Humming Bridge One of her regular walks along the coastline. “When something creepy happens, it reminds me of the creepy sound of the movie. I think it’s a bit sad to get rid of it.”



A quest to solve the mysterious “creepy” ham of the Golden Gate Bridge | San Francisco

Source link A quest to solve the mysterious “creepy” ham of the Golden Gate Bridge | San Francisco

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