Why the strange sound of a “monk singing” emitted by the Golden Gate Bridge in San Francisco

What became clear over time is that it originated from the famous bridge Golden Gate, which is not only the most photographed man-made structure in the United States and the most visited bridge in the world, but also one of the most recurrent places for suicide on the planet.

But no one had a clue what the sound was about.

Several scientists began studying it at universities in the US and Canada, while the phenomenon continued to cause fascination or irritation among residents and visitors.

Videos and sound recordings have gone viral on social media in the last year and a half.

One detail they found after initial measurements was that it often had a frequency of 440 hertz, a sound similar to that of the musical note Do.

They also noticed that it got sharper when the wind blew stronger in a north or south direction.

Now, authorities not only know why the buzzing occurs, they have also come up with a plan to eliminate it.

According to the project approved this month, it will cost almost half a million dollars to make the necessary repairs to reduce noise by up to 75%, which it has been heard up to five kilometers away from the bridge.

Work will begin in the new year and are expected to continue through much of 2022.

After months of study among several universities and with some of the best experts in bridge aerodynamics and acoustics in the world, the authorities in charge of the Golden Gate announced that the sound was due to the impact of the wind against a new railing that they had installed in the sidewalk. West.

As they explained, the structure, more aerodynamic, was added as part of the renovations that were implemented in the bridge and that were destined to help it withstand winds of more than 160 kilometers per hour.

The $ 12 million restoration involved, among other things, replacing the original railing slats with thinner ones.

The authorities indicated then that the renovation was done due to the fear that, as a result of climate change, the winds will become stronger in the coming years and the Golden Gate runs the risk of having the same end as the bridge Tacoma Narrows, in Washington, which began to sway violently in the wind and collapsed in 1940, shortly after it was built.

And is that a study carried out in 2013 showed that the maximum sustained wind speed for which the bridge was built was about 112 km / h. But in its 84-year history, the Golden Gate has had to be closed three times already because stronger winds were reported.

Authorities insisted that the restoration was necessary, but what the engineers did not take into account was the sound that could emanate from the vibrations of the new balusters in the wind.

The headache did not end with finding the cause.

The experts then had to determine how to eliminate the noise that has led many residents to file complaints against the city.

The project, presented this December, will require placing aluminum clips containing a rubber sleeve on each of the 12,000 vertical slats of the west railing.

The Golden Gate District estimates that the cost of making the loops will be $ 450,000.

The bridge was inaugurated in 1937 and is considered one of the wonders of world engineering.

It owes its name to the Strait of Golden Gate, the entrance to the San Francisco Bay from the Pacific Ocean.

Millions of vehicles and people cross its 2.7 kilometers each year and it is one of the main tourist sites in the city.

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