Last week, we posted about some of the information our engineers gathered during their tour of the new San Francisco – Oakland Bay Bridge. Here is part two of our post, with more stories about the construction process.

Great care has been taken to help protect the environment in the planning and construction of the bridge. When driving up to the Yerba Buena Transition structure, there was a section of water near the island that was blocked off by buoys. These buoys designated a zone with eelgrass, a protected marine plant that provides food and shelter to many fish and other local species.  This shows just part of the great effort being made to conserve the environment around the bay bridge, even during construction.

The bay bridge is also home to the largest colony of double-crested Cormorants; these birds make their nests in the underside of the old east span. This means, that along with all of the other construction, special platforms have been added to the underside of the new bridge, so that the birds can make a new home once the old bridge has been taken down. These “cormorant condos” are an effort to protect this species of special concern, and cost around $550,000 to implement. You can read more about these structures and birds in this San Francisco Chronicle article.

The thin platforms along the underside of the skyway are the “Cormorant Condos”.

As a final step in environmental protection, the old east span will be demolished in a different way. There will be no explosions or collapsing bridges, because the original east span was not only built with asbestos, but much of the paint contains lead, and it would be very damaging for those materials to end up in the water. So the old bridge will be cut down piece-by-piece, to ensure that it is disposed of properly, and to keep the environment safe.

One of the many challenges that the design faced was its proximity to historical landmarks and sites on Yerba Buena Island. For example, a torpedo warehouse from World War II is located under the transition structure, and the workers must take extra precautions when working there, being extra careful not to drop any tools, bolts etc. In order to help them remember, the falsework under the bridge is painted grey in that section. However, a real challenge came when it was discovered that the designed bridge would cast a shadow over Nimitz mansion, which belonged to respected admiral Chester W. Nimitz. This was considered disrespectful to the admiral and the historic site, and the Yerba Buena transition had to be shifted so that the mansion would remain always in the sun during the day.

Falsework is painted grey overtop of a historical torpedo warehouse.

While touring the new bridge, there was also ample opportunity to examine the old east span as well. As part of the tour, a “secret” protective troll that is welded onto the bridge was pointed out. It stands on the replacement section of the upper deck; the original section fell during the 1989 Loma Prieta Earthquake. This troll was created by local artist Bill Roan and then welded by ironworkers, without permission, onto the replacement deck. Trolls are commonly known as protectors of bridges, and the industrial troll seems to have done its part since then to protect the east span. It is unclear what will happen to the troll after the demolition of the old east span.

Image courtesy of Wikipedia.

We look forward to the opening of the Bay Bridge in the fall of 2013!

Click here to learn more about the San Francisco – Oakland Bay Bridge. 

On July 24,  a few of our engineers attended an informational session and boat tour of the new east span of the San Francisco – Oakland Bay Bridge, hosted by CalTrans. The east span of the new Bay Bridge includes the Oakland touchdown, the skyway, the self-anchored suspension span and the Yerba Buena transition structure, and it is currently slated to open Labor Day weekend, 2013. Here are some of the facts and stories that stood out.

Our engineers, in front of the self-anchored suspension span.

The self-anchored suspension main cable is quite extraordinary. The cable is 2.6 feet in diameter, and stretches nearly 1-mile long. The cable is made up of 137 bundled “strands”, which are 2.5 inches in diameter. These strands are each comprised of 127 5mm wires, with more than 17,000 single, mile-long wires making up the entire main cable. Each of the 5mm wires is strong enough to hold a military-grade Hummer. Now that’s impressive.

The sample cross section of the main suspension cable highlights the large number of strands by using different colors

Completing the deck of the suspension portion was a feat in itself. The deck is made out of 28 pre-fabricated sections that were brought to the site through the Panama canal. In order to then lift these sections up the “Left Coast Lifter”, a custom crane, was built and is the largest of its kind on the West Coast; the 1,900 ton shear leg crane holds a 328-foot boom, and it supported by a 400×100 foot barge.

The “Left Coast Lifter” moored in Oakland.

The bridge will also be a model for seismic safety innovation. The new span not only has a 150-year expected life, but it is designed for a 1500-year earthquake, making it one of the safest places to be in the event of another major earthquake in the Bay Area. The main tower is comprised of four legs that are connected by shear link beams, which allow all four legs to move independently. The shear link beams can bend and shift, keeping the structure upright and undamaged during an earthquake. There are also hinge pipe beams installed within the deck, which allow for six feet of lateral movement of the bridge (which is a phenomenal upgrade from the old bridge, which only allowed for four inches of movement). A final measure taken to withstand earthquakes is the battered piles under the skyway, which extend 300 feet into the ground for superior stability.

Check out a video simulation of the seismic innovations by clicking here.

Here are some very notable numbers that describe the new bridge:

• 150,000 people have worked on the bridge thus far, from the engineers to the painters.
• 270,000 cars cross the bridge daily, emphasizing the importance of the side-by-side construction of the new bridge, and the coordination required for the Oakland touchdown and the Yerba Buena transition structure.
• The skyway, which makes up 1.2 miles of the 2.2 mile bridge, not only has 2 parallel viaducts that separate the 5-lane east and west-bound traffic, but each deck also includes 10 foot shoulders, that will help keep traffic moving in the event of an accident.
• Combined, all of the skyway elements contain approximately 450,000 cubic yards of concrete, 120 million pounds of reinforcing steel and 200 million pounds of structural steel. The deck sections are the largest of their kind of that have ever been cast, and were made in Stockton, CA.

Stay tuned for our next post, about more interesting features of the new east span.

Click here to learn more about the San Francisco – Oakland Bay Bridge.

We are pleased to announce that Sherwood is moving to a beautiful new office at 58 Maiden Lane, San Francisco CA 94108 effective Monday, February 13. The new space is much larger and allows us to facilitate the interdisciplinary collaborations that are key to Sherwood’s practice, all in a LEED Gold space.

Our new studio is organized around a hub for idea exchange as well as the co-location and expanded headquarters of the Sherwood Institute. It will be a place where architects and clients will be welcome to come for discussions and presentations around the evolving frontier of our professional practice.

To celebrate our new office, we will be having an open house event on April 5, 2012. We’ll send more details about the party soon, as well as photos of our gorgeous new space. So stay tuned, update your address books (please note that our main phone and fax remain the same) and get ready to come visit our new space in the heart of downtown San Francisco on Thursday, April 5!

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Before and after a car-free Broadway

Mayor Bloomberg announced yesterday that starting Memorial Day, Broadway will turn car-free in two heavily congested sections of the avenue, through Times Square and Herald Square.  I will walk out of my way to avoid Times Square due to the pedestrian congestion on the sidewalks, so this measure might actually make me more willing to undertake that feat.

What amazes me the most is that all the reactions I’ve heard are positive, including numerous traffic specialists who say this is a win-win situation, since pedestrians will have more room on a safer road, and that cars will move more smoothly as well since Broadway cutting diagonally across major avenues causes lots of  accidents and slows traffic down significantly.

The car-free Broadway experiment will continue through the end of 2008, and if it runs positively, will be implemented permenantly at that time.

A high tech parking meter for the new parking scheme in downtown San Fransicso

• Drip irrigation may not save water overall, because almost all of the water that is withdrawn from a water source is taken up by the plants, leaving nothing for to replenish the aquifer. So less water may be withdrawn from a source, but since none of it is being returned, its a net loss for the aquifer, especially since subsidies promote the use of drip irrigation, leading to more planting.
• PacifiCorp is planning to endorse a plan to remove four aging hydroelectric dams from the Klamath River in Oregon.
• The Clean Water Act may be used to sue the EPA for not making stricter standards in light of climate change data.
• Pretty much every tree, or living object for that matter, that is over 54 years old will have a spike in carbon-14 levels due to the atomic bomb testing that was occurring.
• California is taking global warming and a rising sea level into account in all their long-term planning, especially when deciding to invest in infrastructure projects that may be under water in 20 years.
• Sustainably designed affordable housing is not expected to suffer significantly from the economic downturn, since there is always a market for affordable housing in NYC. The Tapestry, in Harlem, is one example, that just secured funding recently.
• The Take Back The Filter campaign against Brita has succeeded and Brita will now recycle their filters, via mail or at select Whole Foods locations starting early next year.
• San Francisco is going to go ahead with parking reforms that allow for the Municipal Transportation Agency to fluctuate rates between 25 cents and $6/hr in order to reach a target vacancy rate of curbside parking between 10% and 35%, reducing the need for circling to look for a parking space and increase incentive to not use your car.
• A federal appeals court has banned Royal Dutch Shell from drilling oil wells off the coast of Alaska.
• Can’t say it too many times, electric cars are only as good as their batteries.  And if we start building up electric cars, then we may trade our dependence on foreign oil with dependence on foreign car parts.
• The New York Times runs through a bunch of water saving design features that seem like they are all the rage these days.
• If the federal government agrees to bail out the big three automakers, they should put at least three preconditions the loan – stop resisting environmental regulations, allow for more competition, and make a greater commitment to hybrid cars.

Vaquita Mother and Child from vaquita.org

• A judge blocked New York City’s law to require all new cabs to have a fuel efficiency of 30 mph or greater, a fundamental part of the city’s PlaNYC 2030.
• Boeing is looking at using biofuels as jet fuel within 3 years, but they don’t address the issue of supply – a whole lot of land would be needed to supply that much biofuel.
• Google may make their money in internet ads, but they are investing heavily in renewable energy.
• The vaquita, a type of dolphin in the Gulf of California off the coast of Mexico, is severely endangered with probably no more than 150 left. The Mexican government has been paying fisherman to stop using gill nets or stop fishing all together in an attempt to save the species before its too late. The World Wildlife Fund has been developing alternative nets that are safe for vaquitas.
• Thoreau’s Walden offers a good glimpse as to what the habitat was like outside of Boston 150 years ago and how its changed since then.
• The weed killer atrazine may be responsible for the decline in frog populations across the US, but not for harming the reproduction system, as initially suspected but never proven definitively.  A new study shows it may be due to an increased number of flatworm parasites that infect the frogs, which are rising due to a complex reaction of atrazine killing off algae on the top of ponds, leading to an increase in algae on the bottom of ponds due to more sunlight.  This leads to higher more food for snails, so higher snail populations, which carry the flatworms.
• Solar panels may need more subsidies and government assistance regulations to be successful.

Auto-Free NY’s Plan for Improving the City through Better Transit

Come hear how it works this week.
Tuesday, Oct 28. 6-8pm
Auto-Free NY presents an open forum on key transportation issues. Moderated by Jeffrey Gold, Vice-President, Institute for Rational Urban Mobility.

More info on Sustainable Streets in New York City in SF this week from SPUR:
Wednesday, Oct 29. 12:30 – 1:30pm. SPUR Office, 312 Sutter St. (at Grant), 5th Floor. Close to the Powell St. BART station and several Muni lines. Feel free to bring a lunch. SPUR Forums are open to the public, free for members and $5 for non-members.

New York’s Department of Transportation has transformed in recent years into one of the country’s leading advocates for sustainable streets. Jon Orcutt, the agency’s Director of Policy, will discuss the agency’s strategic plan, released in April 2008, and the variety of projects and initiatives designed to align the department with the goals and challenges of Mayor Michael Bloomberg’s PlaNYC 2030 sustainability initiative

What’s “Humanure”??
Thursday, Oct 30. 7:30 – 9:00pm. 6th Street Community Center
638 East 6th St (btw Aves B and C), in Manhattan

Permaculture Solutions Lecture Series presents: “Humanure” Humanure – the odorous excretions of human beings – can be recycled using natural processes without creating environmental pollution. And it can be done in your own backyard. Joseph Jenkins will cover this topic at least a couple inches deep. Joseph Jenkins, a businessman, organic gardener and author of three books, is perhaps best known for the award-winning Humanure Handbook – A Guide to Composting Human Manure, which is making its way to various United Nations and international development networks, and has been translated into Korean, Hebrew, Spanish, Norwegian and Mongolian.  From the Green NYC Events calendar.

Have a Great Week!

Sheep being led back to the ranch.

• Downtown Houston converts an above ground parking lot into a below grade parking lot with a park on top, creating open space downtown.
• Bike sharing programs are becoming more popular on college campuses, and getting more technologically advanced at the same time.
• The economic crisis and the decrease in gasoline and fuel costs may cause the renewable energy trend to stall.
• California’s energy efficient policies have created close 1.5 million jobs over the last 30 years, while losing less than 25,000. Since consumers were spending less on energy, they spent more on other areas, creating jobs.
• Google has created a Halloween themed energy savings calculator for greening your home.
• Charging your phone or ipod while you walk may become a reality.
• Corn ethanol uses a lot of water – 36 gal of water per mile driven by a typical car on the fuel.
• Some people are taking living green a bit too far, leading people to make a new term for them – energy anorexics or carborexics.
• A device called the Blade can attach on to the tail pipe of almost any car out there and filter particulate matter from the tail pipes. The device costs $199 and the filters that come with it are good for two years.
• Hybrid buses, produced by a local company, are under-performing in Toronto, despite successes in San Francisco and New York. It may be because they are used primarily on suburban routes, where stop and go traffic, where hybrids perform best, aren’t as regular occurrences.
• A car that runs off of compressed air is currently in development.  It can reach top speeds of 40 mph, with a range of greater than 130 miles and can seat three.  Prototypes are expected to be available in Europe next year, hitting the US in 2010.
• Both of the candidates have plans involving plug-in and alternative energy vehicles.  Obama’s plan involves converting the White House fleet to plug-ins while McCain’s plan focuses on a $300 million prize to develop more a economical battery.
• Working towards its goal of becoming carbon neutral by 2010, the Port Authority of New York and New Jersey will start a program to allow commuters to purchase carbon offsets.
• For the first time in over 30 years, a nuclear power plant might be constructed in the US.  34 nuclear power reactors are planning on seeking permission to build from the Nuclear Regulatory Commission in the next year, the majority of which will be built in the south.  This boom is bringing a lot of construction to the south as well, some of which is for export.
• Using sheep to graze away the weeds on large swaths of land is a growth industry.  Its a low fossil fuel endeavor, has aesthetic appeal, and produces wool and meat as byproducts.

Wired has an interesting article up, “Note to Next President: Modern-Day WPA Will Save the Economy”

“The state of America’s infrastructure — roads, bridges, drinking water, even schools and transit systems — couldn’t be much worse. A report card issued three years ago by the American Society of Civil Engineers gives it all a D. The society says we’ve got to spend about $1.6 trillion just to bring things up to a B-”

Is the economic meltdown an ideal opportunity to invest in long-term infrastructure projects, create jobs, and modernize our rails and roads? Or is it a government boondoggle that will undercut private industry and prolong our economic recession? Is the labor-intensive model of the WPA an accurate comparison for today’s hi-tech projects that require highly-skilled workers?

The writer says:

“The candidates can talk all they want about shoveling money into alternative fuels, electric cars and high-speed rail, but none of that will mean much if our roads, bridges and rails can’t support them. The next president must commit to fixing our infrastructure. Such an investment will create jobs, strengthen our economy and make America more competitive.”

Should wind-power, large-scale solar, and a new smart energy grid be part of the next president’s agenda? What about high-speed rail in California?

What do you think?

We’d love to hear!

A vegetable oil powered car won the race from the Bay Area to Las Vegas. (New York Times)

• A race from San Francisco to Las Vegas has a twist – all cars start with just one gallon of a fuel of their choice and they must scavange for the rest of their fuel on their home made vehicles.  A vegetable oil fueled car won the race, where the only other finisher (only 5 vehicles started) was a wood burning car.
• The New York City Parks Department, which managed Shea Stadium, is removing bathroom and lighting fixtures for use at other Parks Department facilities, among other items, prior to demolition of the stadium. (via greenbuildingsNYC)
• Toyota won a fuel efficiency challenge last week in a race in the UK, with its Yaris 1.4D-4D (diesel) car achieving 70.49 MPG for the 400 mile race. The best gasoline car mileage was the Toyota Aygo with 68.6 MPG. Too bad neither of the vehicles are available here in the US.
• Global warming is creating a negative feedback loop by reducing the amount of water in peat bogs, leading them to dry out and decompose, which thereby releases more carbon to the air.
• Check out the solar potential for your home easily with this map (if you’re in North America that is…)
• After the energy crisis in the 1970s, a lot of money was invested finding new fossil fuel resources, but just a few million were granted to a research group in Berkeley to reduce energy demands. They realized widows were a big energy sink and basically created the market for low-emissivity windows, paving the way for the glass towers of today.
• The UK announced an employment program that will train workers to insulate attics, in a new program called the Conservation Corps.
• Michael Pollan writes an open letter to the next President about how to reform food laws so that Americans gain a healthier diet, reduced dependence on foreign oil, and greater national security.
• The Vietnamese catfish has been having a huge impact on the American catfish industry.  But are they on the same playing field from an environmental and food safety standpoint?
• A vast natural gas reserve is located below New York, Pennsylvania and West Virginia, but accessing it may cause contamination of the water supply.
• Traffic could be impacting our health in one way not many of us would suspect. A study done in San Francisco showed that 1 in 6 residents of San Francisco may be suffering from higher stress rates from the increased noise levels due to traffic, and that puts them at risk for heart disease, high blood pressure and other stress-related illnesses.
• Gainsville, Florida, may adopt feed-in tariffs, which would guarantee to buy all power produced by solar PV systems at a set price for the next 20 years, creating a more stable market for solar power.  This program is an alternative to a net metering program, which is more expensive to administer.