Wind, Water & Steel: The New Bay Bridge
SAN FRANCISCO (KPIX 5) — For 24 years, it’s the icon the Bay Area has been waiting for: the new Bay Bridge.
Say goodbye to the dreaded S-curve. It will be gone faster than you can say “Labor Day.” May it Rest In Pieces. People will have to learn how to drive in a straight line again.
“I think the most surprising thing is just how wide it is,” said bridge spokesman Andrew Gordon. “Just like the original bridge, this will be able to accommodate five lanes of traffic in both directions. But there’s also going to be 10-foot wide shoulders on both sides of both decks. So if there’s an accident, if the highway patrol needs to pull somebody over, if there’s maintenance going on, they don’t need to take one of the existing lanes of traffic. They just move off to the shoulders and traffic can continue to flow.”
At night, the road will be evenly illuminated and glare-free thanks to 48,000 individually-aimed LED bulbs. Lead architect Donald MacDonald says he tried many designs before he was satisfied.
“We did about 10 different cable systems,” said MacDonald. “We ran the cables perpendicular, we ran down rows, and singular, and all that stuff. And I said, ‘We need like a veil of light.’ So when you go from the tunnel, and you come out, you go through this lighted veil of these cables. And it’s just going to be spectacular because each cable will be lit.”
In daytime, cars headed east will be treated to wide-open views of the East Bay cities and hills. Bicycles and pedestrians will get the same vistas.
It’s been a long time coming for residents who felt their hometowns got short shrift compared to the sweeping views of San Francisco drivers get from the Western span.
More than a little consideration went into the very “experience” of this bridge. The Bay Area is considered by many to be the region that ignited a worldwide movement to protect the natural world around us — the concept we now know as Environmentalism. So what happens when you want to add two miles of concrete and steel to a slice of nature like San Francisco Bay? Page after page of permits from the Bay Conservation and Development Commission (BCDC) and other regulatory agencies detail strict requirements Caltrans has had to meet to build the new span in a sensitive space.
It hasn’t always been this way. The gold rush brought people to the Bay Area who wanted to use nature, not protect it. Hydraulic mining washed tons of mercury into the bay. Settlers chopped down the oak groves that gave Oakland its name. Small islands in the bay were dynamited to make way for ships. Then came the bridge — and urban sprawl.
“Changing agricultural land over to suburbs,” historian Louise Pubols said. As senior curator of the Oakland Museum, she’s directing the newest exhibit, exploring how people interact with the bay.
“If you look at how the Old Bridge was built in the 1930s,” Pubols said, “that’s a particular moment where Americans felt very optimistic about building huge infrastructure projects that they believed would improve on nature.”
That was certainly the case with the Golden Gate Bridge, where drivers are surrounded by beauty even as they rush along. But there’s no embrace from Mother Nature in the steel trusses of the Eastern span.
“The Old Bay Bridge they weren’t really thinking about creating those vistas for you,” Pubols said. “It’s kind of got the personality of Oakland. It’s got this working class, get it done, workhorse sensibility. It moves a lot more traffic than the Golden Gate Bridge.”
She says the new Eastern span strives for better balance with the environment.
“I think it puts you back in touch in a certain way with where you are. And it kind of grounds you in that place, even though you’re flying above it. It does remind you that you are living in a particular place that has a lot of natural beauty. And that is a certain type of relationship that people have with nature.”
BRIDGE VS. ELEMENTS
Ask most Bay Area residents what they think about our weather and they respond with words like “pleasant,” “quiet,” or “nice.” Ask engineers building the new bridge the same question and they use terms like “corrosive,” “humid,” and “stormy.” It’s the battle between cool Pacific air and hot valley air, and the first weapon of choice is Wind.
“Wind is probably the biggest thing on my mind when I think about adjustments we might need to make,” said Caltrans Chief Engineer Brian Maroney, citing the challenges of building a bridge exposed to the elements every minute of every day. For example, the pentagon-shaped light poles look nice, but they’re not round, so they absorb more of the wind’s energy.
“These things move,” Maroney said. Everything that sticks up in the wind moves. So it is moving, but I need the base of this (light pole) to perform such that it can hold it well so it will perform for a long, long, long, long time.”
Maroney points to the famous Tacoma Narrows bridge that failed dramatically back in 1940. “Galloping Gertie,” as the suspension span came to be known, until it was ripped apart.
“When the wind blows across the top and down below…all bridge structures have the potential to start moving up and down. The question is how much? Some is fine. Too much is not okay.”
The new Bay Bridge uses so-called “vortex shutters” – metal flaps beneath the suspension span that disrupts wind flow to minimize its impact on the bridge.
But when you’re talking weather, it’s not just the wind. It’s also what the wind carries with it: humidity and salt. Not a good thing. Because when you combine salt, water and steel, you get corrosion and rust. It can happen quickly. When Caltrans scraped off some paint from the old Bay Bridge to see how quickly the steel would oxidize, it took one day for new rust to show up.
So the goal is easy: keep humidity and salt as far away from the steel as possible. Given the bridge’s location, that’s easier said than done. It’s kind of like going to the beach — sand gets everywhere. Out in the bay, water and salt gets everywhere.
First up: Water. The relative humidity hits 100-percent most days. So engineers are using a fancy, bigger version of something you may have at home: a de-humidifier.
“Dehumidifying is an engineering term for air conditioning,” explained T.Y. Lin engineer Marwan Nader, chief designer of the new bridge. “Basically we are taking the insides of the box girders and inside of the cables and we are taking the humidity out.”
They also use layers of special paint to protect the steel. The trick is to apply the paint under typically bad conditions – high humidity and salt. The crews use special tarps to create tiny dry areas so the coatings will stick.
Before Ikea and the Emeryville Mall, before The Maze of freeways, the East Bay shoreline was very different. A non-profit Oakland company called CyArk has produced a unique video showing how the area looked hundreds of years ago. The natural bends of Temescal Creek. The Tule huts of Native American settlements. And the biggest and most revered man-made monuments of their time: the Emeryville Shellmounds.
“We thought it would be a great idea and really cool for the public to experience something virtually, be able to walk around something that doesn’t exist,” said CyArk project manager Scott Lee.
CyArk technicians usually travel the globe, using lasers and computers to create digital models of world heritage sites like Mount Rushmore or Machu Pichu. Scans can be used to digitally preserve sensitive sites against the ravages of time, natural disasters, or human destruction.
The Shell Mounds were destroyed by developers in the 1920s.
“I think some people don’t understand what you have until it’s gone,” said CyArk vice president Elizabeth Lee. “That site wasn’t preserved, it’s been lost. So what we were able to do is use technology to share the story of that site and help communicate the importance of these places.”
CyArk poured over old Spanish maps, early photos and documents, and even the oral histories of the Muwekma Ohlone tribe to pinpoint the location and size of the mounds. They were about 60 feet high, made up of dirt and millions of clam, oyster and mussel shells from Native American meals. But they also contained the burial grounds of the tribe’s most prominent members.
“The site before Ikea and before Bay Street was an important cultural heritage site,” Scott Lee said. “We document sites that everyone knows, the pyramids, Mt. Rushmore, monumental sites. But sites like the Shellmound is just as important as those sites.”
With help from the San Francisco Estuary Institute to portray the correct ecology, the project takes on a 3-D perspective not seen since before Europeans arrived at the bay. Elizabeth Lee told us, “Through this tech we help tell that story so people can recognize this was a place of cultural significance, this was the equivalent of their Great Pyramid of Giza.”
The video was produced for the Oakland Museum of California. The video will be projected on a 22-foot high screen as part of a new museum exhibit called “Above and Below: Stories From Our Changing Bay.” This and other displays will explore how the convergence of human engineering and natural forces have shaped and reshaped the land and bay.
The exhibit runs from August 31 to February 23, 2014. The Oakland Museum is at 1000 Oak Street.
Engineers took every care during construction of the new Bay Bridge to protect wildlife. To protect fish and marine life from the sound of pile driving, they used a curtain of bubbles to help keep animals away and muffle the sound waves.
“As they hammer on the steel piles, it’s like ringing a bell underwater,” biologist Lauren Bingham told us. “By creating this wall of air, it’s attenuating the sound waves coming off the pile. It lessens the noise impact to the bay and it protects fish and marine mammals.” Bingham says the bubble curtains don’t just save the lives of these animals, but reduce stress the sounds may cause.
And it’s not just animals in the water. There’s a big effort to save a colony of double-crested cormorants nesting on the old span. They’ve made it their home since the 1980s – nesting in the girders below the roadbed, dropping down to snack in the bay, or just hanging out.
“We have nests spanning at least a mile of the old bridge,” Bingham said.
But when the old bridge gets torn down, their homes will go too. Caltrans’ solution is to move the colony to the new bridge – except the new bridge is not quite as bird friendly.
“Very streamlined,” pointed out Bingham. “There wasn’t any kind of nooks and crannies like on the old bridge for the cormorants to nest on.”
So Caltrans spent half a million dollars to build “cormorant condos” – stainless steel platforms underneath the new bridge that can accommodate a thousand birds.
To attract the flock, loudspeakers blast out cormorant breeding calls. And biologists have stocked the platforms with nests made from old Christmas wreaths, along with dozens of plastic decoy birds.
“It’s supposed to create a sense of safety,” Bingham said. “Because it’s showing that other birds are congregating in the area, and that this place is safe.”
There are even mirrors to get their attention and make them think they’re seeing another bird.
But as everyone knows, moving is a pain. So far, the cormorants haven’t budged from the old bridge.
“We’re trying to get into the mind of a bird here,” Bingham explained. “You can only do so much.”
Eventually Caltrans will have to block off the old nests and force the birds to choose: fly away or move next door. Bingham is betting on the cormorant condos.
“You can’t take a bird, pick it up, put it on a platform and tell it to stay. So we hope that they will utilize the platforms.”
DISMANTLING THE OLD BRIDGE
You might think the easiest way to get rid of the old Eastern span is to simply blow it up. But can’t happen in San Francisco Bay.
“That’s not exactly environmentally sensitive, right,” said chief bridge engineer Brian Maroney. “So we’re looking for better ways to do that, especially because this [bridge] is covered with lead.”
Brad McCrea with the Bay Conservation and Development Commission (BCDC) is in full agreement. “Blowing up the Bay Bridge would result in lead paint in the water. Would result in degradation of water quality. Would harm fish.”
It took three years to build the old bridge. It could take twice as long to take it down – piece by piece.
“We need to carefully think about which part do we take apart next,” Maroney said. “The sequence that we follow to deconstruct this structure is very important. You pull out the wrong member first? It’s a bad ending.”
The goal is to avoid anything resembling what happened in the Loma Prieta earthquake. And agencies like BCDC will be monitoring the work to make sure the bay is protected from any fallout.
“Even the smallest item that falls off the bridge has to be removed from the bay,” McCrea said – even something as small as a wrench. “Its considered at that point debris. and it’s not really about a wrench falling in the bay. it’s about what it means.” What it means is zero tolerance for polluting the bay.
Work to get ready to take the old bridge down started six months ago. The moment the new span opens, crews will begin stripping off the roadway, then cutting through the exact center of the cantilever section. Crews will then begin dismantling the bridge in the reverse order of how it was built. Within months it will have an expanding gap, looking much like it did during construction in the 1930s. It will take two years and $10-million just to take apart the cantilever span. After that, other tresses will come down piece by piece.
The final phase involves taking down the steel towers to 10 feet below the mud at the bottom of the bay. The Coast Guard will be watching to making sure there’s nothing left to present a navigational hazard.
Adding a rail system to the new bay bridge was a consideration early in the planning process. So in case the Bay Area ever wants that system, the span has been built strong enough to carry it. But it wouldn’t be the first rail line on the bay bridge.
The original design for the Bay Bridge was for two-way auto traffic on the upper deck – buses, trucks and trains on the lower deck. Those trains were electric – clean public transit decades before environmentalism.
The “Key System”, as it was called, ran throughout the East Bay and across the bridge, taking up half of the lower deck.
“It was exciting to take the train across the bridge,” said John Holt of the Western Railway Museum near Rio Vista. “The goal was to ride on the train more than go to San Francisco. And you could look out, see the City, you could see the ferry boats at that time, and you were up high – much higher than a car – so you could see all these things.”
“Public transit ruled the day up until pretty much through World War II,” said museum director Phil Kohlmetz. “There was definitely competition from cars in the 1930s even though it was the Depression, but the war effort really kind of heightened the reliance on public transit and the importance of public transit.”
The Western Railway Museum has two Key Trains in its collection, and engineers still take Car 187 out for short runs – a rolling reminder of times when you could help stop Hitler by buying War Bonds; and doctors touted Lucky Strike cigarettes for protection against throat irritation.
Each car had seats for 124 people, dozens more standing. It could get stuffy because the windows didn’t open. But they did have some creature comforts. Match strikers next to the seat made it easy to light up. And so-called “walkover” seats could be reversed, allowing passengers to face each other and both enjoy a smoke.
But things changed quickly after World War II.
General Motors, Firestone Tire, and Phillips Petroleum took over the Key Trains and began dismantling the system — as they did in Los Angeles and elsewhere – to push more people into using automobiles.
“Ridership for the Key system is declining,” Kohlmetz explained. “Demand for cars is going up and up and up, and public demand for auto transportation on the bridge finally necessitated them ripping out the tracks on the bottom deck.”
The last train crossed from San Francisco to Oakland in 1958.
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