If you live in the Bay Area, a foggy day can be a good excuse for some guilt-free time indoors. If you live near the water, days like that bring something else: foghorns.

That’s the topic of a question we got at Bay Curious.

San Francisco residents Andy MacKinnon and Jen Liu live in the Sunset District near Ocean Beach.

From their apartment, MacKinnon says, “We can see the fog rolling in off the ocean and creeping up the street until our house is completely engulfed by fog. And shortly after that happens, we start hearing foghorns.”

Jen Liu and Andy MacKinnon. This pair is bay curious about fog horns.
Jen Liu and Andy MacKinnon. This pair is curious about foghorns. (Courtesy Andy MacKinnon)

Sometimes they can hear three foghorns all at once, and it’s hard to figure out where they’re coming from.

MacKinnon and Liu have a boatload of questions about the sounds that help vessels navigate safely through the water. They want to know:

  1. Where are these foghorns?
  2. How many of them are there?
  3. Why do we still use them despite technologies like radar and GPS?
  4. Who or what turns them on?

Let’s find some answers.

Where are the foghorns and how many are there? 

We start on Yerba Buena Island, right in the middle of the Bay Bridge, with U.S. Coast Guard Petty Officer John Sherwood of the Aids to Navigation Team San Francisco. One aspect of his job is maintaining foghorns, lights and other signals that are essentially the road signs of the water.

U.S. Coast Guard Petty Officer John Sherwood poses with a map of sound signals across the San Francisco Bay.
U.S. Coast Guard Petty Officer John Sherwood poses with a map of sound signals across the San Francisco Bay. (Laura Klivans/KQED)

Sherwood shows me a map listing these aids to navigation — things like buoys, signs and foghorns. Sherwood counts 11 foghorns that the Coast Guard operates in the bay, and roughly 20 more operated by other entities.

“We have horns located at Point Bonita, Yerba Buena Island, Alcatraz Island, Angel Island,” he says. They’re not only on islands, but also at bridges and lighthouses.

Each foghorn has a distinct sound and plays at a different interval, which is intentional. Sherwood says that in low visibility it’s possible to figure out which point of land is closest if you learn the sounds of each foghorn well enough.

Sherwood also shows me around a Coast Guard parking lot. It looks like an island of misfit toys, with several 20-foot-long metal buoys on their sides.

A buoy with a bell on it awaits repair in this "buoy depot" next to a U.S. Coast Guard building on Yerba Buena Island.
A buoy with a bell on it awaits repair in this ‘buoy depot’ next to a U.S. Coast Guard building on Yerba Buena Island. (Laura Klivans/KQED)

Sherwood calls this area a “buoy depot.” Here, the Coast Guard repairs buoys to put them back out in the water. The buoys are important instruments in the orchestra of the sea. Foghorns make music, but buoys do as well.

Sherwood says some buoys have huge bells that sound off when swayed by rough waves. Others have gongs — made of stacks of metal plates. And there are also whistles.

Sherwood says that if we think we’ve never heard these before, it’s more likely that we don’t recognize them or know to listen for them. Some of these noises could be making their way to MacKinnon’s and Liu’s apartment, too.

Why do we still use foghorns if we now have sophisticated navigational systems?

To answer this one, I go to Vallejo, right by the Carquinez Bridge, to the California State University Maritime Academy. It’s an institution that teaches students the ways of the sea.

Training Ship Golden Bear's Captain Harry Bolton looks out from the ship's bridge.
Training Ship Golden Bear Capt. Harry Bolton looks out from the ship’s bridge. (Laura Klivans/KQED)

Harry Bolton is the captain of the United States Training Ship Golden Bear. He shows me two large computers in the ship’s bridge, which is like a command center.

Bolton says the ship’s radar and electronic navigation systems use the latest technology. But not all boats are equipped with it. Smaller vessels especially may still need foghorns to guide them.

“We sound the fog signals, so that if they don’t have this equipment they can avoid hitting us,” Bolton says.

He says all these sounds, including the simpler technologies, are redundant, and together they make the bay a safer place.

The smoke stack of the Training Ship Golden Bear is adorned with a foghorn and a golden grizzly bear. The over 10,000-ton ship serves as a training vessel for students attending California State University Maritime Academy.
The smokestack of the Training Ship Golden Bear is adorned with a foghorn and a golden grizzly bear. The over 10,000-ton ship serves as a training vessel for students attending California State University Maritime Academy. (Laura Klivans/KQED)

So when it seems to MacKinnon and Liu that a foghorn is like a moving target, it’s because it might actually be a horn coming from a ship.

Who or what turns on the foghorns?

These days, a lot of foghorns are automatic. Angel Island, for example, has a sensor that detects particulates in the air. When there are enough particles, the foghorn goes off.

But some foghorns, even some very important ones, require a human to flip a switch or press a button.

This brings us to our final stop: the Golden Gate Bridge. Our guide is operating engineer Mario Territo with the Golden Gate Bridge, Highway & Transportation District.

When the bridge opened in the 1930s, he says, there were a lot of complaints from people who lived in San Francisco  because they were being kept awake by the foghorns.

“They run 149 decibels,” Territo says. That’s nine decibels louder than the point at which a person starts to feel pain.

So, Territo says they redirected the foghorns more toward the center of the bay.

“And then the Alcatraz prisoners were complaining that it was interrupting their sleep,” he says. Those complaints were largely ignored, however, and the foghorns stayed that way.

I meet Territo with the goal of seeing the Golden Gate Bridge foghorns. They’re frequent favorites with some nautical experts because of their design: The horns run on compressed air, while more modern ones are electric. I also want to get a sense of just how loud these are, and find out who turns them on.

To get to two out of the five foghorns on the bridge, we have to go down 240 feet through a secret door that, if you’ve ever walked across the Golden Gate Bridge, you have passed and likely not noticed. Then we squeeze into a phone booth-size elevator inside the South Tower of the bridge.

When we scramble out onto a concrete platform, we’re just 40 feet above the bay waves.

A rare view of the Golden Gate Bridge from the concrete base of its South Tower.
A rare view of the Golden Gate Bridge from the concrete base of its South Tower. (Brittany Hosea-Small/KQED)

“As you can see, we’re on the South Tower Pier,” Territo says.

He points to two orange tanks on the concrete platform. They are each about the size of a four-door car.

“We had an original air tank for the foghorns that was put in here in 1937 and it rusted out about a year ago,” he says. They’ve replaced both.

The foghorns work by pushing compressed air through the noisemakers. This air is pumped to the tanks from a building right by the bridge toll booths.

At one end of the platform where we stand, there, in all of its international-orange glory, is a 4-foot-long foghorn.

Mario Territo, operating engineer for the Golden Gate Bridge Highway & Transportation District, shows off this international-orange foghorn.
Mario Territo, operating engineer for the Golden Gate Bridge, Highway & Transportation District, shows off this international-orange foghorn. (Brittany Hosea-Small/KQED)

We shove neon earplugs into our ears. Territo radios engineers to blow the foghorns. The way they operate something very old is through something very new: a touch-screen monitor. While it’s not foggy in the slightest, they do it. For me. For you. For Andy MacKinnon and Jen Liu.

Territo summarizes the feeling best.

“If you’re standing next to it,” he says, “it vibrates your bones.”

Foghorns: Who Presses The Play Button? 20 January,2017Laura Klivans

  • michaelshag

    Thank you! Great story. One of the great reasons to live in San Francisco

  • Jordon Wing

    Heads up – the Google Play version of this is messed up. It’s only 6 seconds long. 🙁

    • Olivia Allen-Price

      Thanks for taking the time to alert us Jordon. We had a technical issue with our podcast deployment Thursday morning, but you should be seeing a fixed episode in your queue shortly. Hope you can listen!

  • Meander Awn

Author

Laura Klivans

Laura Klivans is a community health reporter at KQED. In addition to KQED, her work can be heard on NPR, Here & Now, and PRI. Before getting hooked on all things audio, she worked in education, leading groups of students abroad. One of her favorite jobs was teaching on the Thai-Burmese border, working with immigrants and refugees.

Laura won the 2016 North Gate Award for Excellence in Audio Reporting and Production and the Gobind Behari Lal Award for Excellence in Reporting on a Science or Health Story for a radio documentary about adults with imaginary friends. She’s done many fellowships, including UC Berkeley’s Human Rights Fellowship and the Coro Fellowship in Public Affairs. Laura has a master’s in journalism from U.C. Berkeley and a master’s in education from Harvard.

She likes to eat chocolate. For breakfast.

lklivans@kqed.org, twitter: @lauraklivans, www.lauraklivans.com

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