For more information on the Central Subway Project, please see our website.

Tunnel boring machine Big Alma, shown here on the right, began tunneling under 4th Street. On the left is the entrance to the parallel tunnel being built by TBM Mom Chung.

There are now two 350-foot-long, 750-ton tunnel boring machines mining under 4th Street to construct the Central Subway’s pair of parallel tunnels. Our second TBM, named Big Alma, recently launched. She’s building the tunnel that northbound T Third Line trains will use when the Central Subway opens in 2019.

Over the coming months, Big Alma will travel north under 4th Street and Stockton Street, building tunnel at an average pace of 40 feet per day. Her tunnel will be just east of the tunnel that her twin, named Mom Chung, began building in July. Big Alma will move more slowly during the first 500 feet of tunneling, as Central Subway crews test the TBM and calibrate its many functions.

Big Alma is named for “Big Alma” de Bretteville Spreckels, a 19th century socialite and philanthropist who, among her many accomplishments, persuaded her first husband, sugar magnate Adolph B. Spreckels, to fund the design and construction of the California Palace of the Legion of Honor, at Land’s End in San Francisco. A model in her youth, Spreckels was the inspiration for the “Victory” statue atop the Dewey Monument in the center of Union Square.

The photos below show Big Alma the TBM during her assembly and launch. To learn more about Big Alma and her underground journey to build San Francisco’s first new subway line in decades, check out this press release from the SFMTA. You can also follow the machine on Twitter. She’s @BigAlmatheTBM.

This section of Big Alma’s “shield,” the portion of the machine that puts in place the tunnel segments, was among the first to be lowered into the launch box.

Known as the “cutter head,” this part is on the front of the machine, attached to the shield. It excavates the earth to make room for the new tunnel.

The cutter head is lifted by a crane and lowered into the launch box.

Underground, crews connect the cutter head to the shield.

A welder welds together two sections of Big Alma’s shield.

After the shield and cutter head were assembled, crews moved them to the northern end of the launch box, where tunneling begins.

Crews work in the launch box, preparing to move Big Alma forward.

In the launch box, Mom Chung is on the left, tunneling, and Big Alma is on the right, being assembled.

Crews assemble the trailing gear of Big Alma. This 300-foot train of tunnel-building mechanisms performs a variety of important functions.

Once assembled, the trailing gear stretches almost the full length of the launch box.

A welder works on Big Alma’s shield in the weeks before launch.

Tunnel segments are lowered into the launch box for installation by the TBMs.

After Big Alma’s launch, a tunneling crewman walks out the back of the machine. We thank our crews for their hard work as they build San Francisco a new subway line.

San Francisco Mayor Edwin M. Lee takes a look at tunnel boring machine Mom Chung in the excavation under 4th Street where tunneling will begin.

Yesterday, Mayor Edwin M. Lee paid a visit to the construction site where tunneling will begin and saw Mom Chung, the 350-foot-long tunnel boring machine currently being assembled underground.

Speaking to reporters in front of the digging cutter head of Mom Chung, Mayor Lee said he was excited about the Central Subway, calling the T Third Line extension “one of the most important projects for the future of San Francisco.”

SFMTA Board Chairman Tom Nolan, SFMTA Director of Transportation Edward D. Reiskin, Central Subway Program Director John Funghi, key city officials and members of Central Subway team accompanied Mayor Lee under 4th Street to show him the major excavation where tunneling will begin. Check out the photos below for more on the Mayor’s visit to this important construction site.

The tour group heads down the ramp near 4th and Bryant and into the excavation beneath the roadway.

The tour group makes its way through the excavation and toward Mom Chung. From left to right: Director Reiskin, Mayor Lee, John Funghi, tunnel contract Resident Engineer Sarah Wilson.

Sarah Wilson, the engineer overseeing construction of the Central Subway tunnels, explains the details of the tunneling process to Mayor Lee. From left to right: SFPUC Assistant General Manager Emilio Cruz, SFPUC General Manager Harlan Kelly, Jr., Mayor Lee, the Mayor’s Chief of Staff Steve Kawa, John Funghi, Sarah Wilson.

Mayor Lee responds to questions from reporters. From left to right: Director Reiskin, Chairman Nolan, Mayor Lee, John Funghi, SFMTA Board Vice Chairman Cheryl Brinkman, Sarah Wilson.

The tour group gathers around the front of Mom Chung. Called the cutter head, this spinning excavator will dig through the earth under 4th Street, Stockton Street and Columbus Avenue.

Representatives of tunnel construction contractor Barnard Impregilo Healy meet Mayor Lee and Director Reiskin. From left to right: Assistant Project Superintendent Andy Granger, Mayor Lee, Project Manager Ben Campbell, Director Reiskin.

Read more about the Mayor’s visit in today’s San Francisco Chronicle. Tunneling is slated to begin in June.

School kids, community members and the Central Subway team show their support for the T Third Line extension.

San Francisco needs the Central Subway, said the San Francisco Examiner’s editorial board in a column published this weekend.

With major federal funding for the project now approved, this essential public transit investment will “tie together some of the fastest-growing neighborhoods in San Francisco with the densest community on the West Coast” and “help The City more effectively handle the growth that is projected over the next few decades.” These important advantages, the Examiner argues, make the project “beneficial to all of The City and people who live and work here.”

The Central Subway will extend Muni’s T Third Line through central San Francisco.

In today’s San Francisco Examiner, the editorial board strongly endorses the Central Subway project, saying the extension of the T Third Line through SoMa, Union Square and Chinatown “will be a major asset to San Francisco”:

“It is time for everyone to get onboard with the Central Subway project — the largest Muni project in recent years.”

The editorial board writes that the 1.7-mile Central Subway will enhance the city’s transportation network by connecting SoMa and Chinatown – “one of the fastest-growing sections of The City with one of the densest neighborhoods in the nation” – while extending the T Third Line, “a 5.1-mile light-rail line that has done much good by connecting downtown with the southeastern neighborhoods of The City.”

The T Third Line is projected to become Muni’s most heavily used line soon after the completion of the Central Subway. It will connect transit customers with vibrant neighborhoods, crucial job centers, premier commercial districts and world-renowned tourist destinations, making it a worthy and needed investment in public transportation in San Francisco.

Read the entire editorial at sfexaminer.com.

“A worthy and crucial investment in San Francisco’s transportation infrastructure.” That’s how Tom Nolan, chairman of the San Francisco Municipal Transportation Agency (SFMTA) Board of Directors, described the Central Subway in a recent editorial to the Wall Street Journal.

Responding to an opinion piece by the paper’s editorial board, Nolan noted that the Central Subway will provide a rapid transit option through San Francisco’s vibrant urban core, cutting peak-hour travel times by more than half along the project alignment:

We are building the new subway to address pressing transportation needs in these densely populated neighborhoods. Currently, crowded buses crawl through this corridor at about three miles per hour, moving even more slowly during rush hour. With traffic congestion only expected to get worse, surface transportation solutions will provide an inadequate fix. The Central Subway, in bypassing crowded city streets, will cut peak-hour travel times by more than half.

For these reasons and more, the project continues to enjoy strong support from local business, labor and merchant communities, and the federal government, as a part of its rigorous review process, has consistently given the project strong positive ratings.

Check out the rest of Nolan’s editorial here, on the Wall Street Journal’s website.

Mayor Lee spoke about the benefits of the Central Subway today at a press conference in Chinatown.

The Central Subway will improve public transportation in San Francisco, create thousands of jobs and enhance the quality of life of residents and visitors alike. That’s what Mayor Edwin M. Lee and other local leaders and community members said at a press conference today at the site of the future Chinatown Station, hailing the Central Subway as an essential and much-needed investment in the city’s infrastructure and economic future.

“Once the Central Subway is built, this new light-rail extension will be an engine for job creation and economic growth in our city, connecting our vital neighborhoods and diverse communities,” said Mayor Lee. “This important investment in our city’s infrastructure will improve transportation options, reduce emissions and enhance the quality of life of residents and visitors.”

Mayor Lee, San Francisco Municipal Transportation Agency (SFMTA) Board of Directors Chairman Tom Nolan, San Francisco Board of Supervisors President David Chiu and others gathered to unveil a decorative vinyl wrap installed at the site of the future Chinatown Station. The wrap, which features renderings of the station design, a mural provided by the Chinese Historical Society of America and artwork by students from the Chinatown YMCA, will protect and enhance the appearance of the now-vacant building at 933 to 949 Stockton Street until it is demolished later this year.

The building has been acquired by the SFMTA, and, with SFMTA assistance, all residential and commercial tenants have successfully relocated.

Top: 933-949 Stockton Street with the artistic wrap. Bottom: The building before the wrap was installed.

The station, a subway station to be constructed at the southwest corner of Stockton and Washington streets, will feature an open, contemporary aesthetic that emphasizes transparency and simplicity. Light-colored and reflective surfaces will maximize lighting efficiency and create a bright, welcoming atmosphere even when customers are below ground. Artwork selected through the San Francisco Arts Commission’s Public Art Program will adorn the station and provide insight into local culture and history.

These renderings depict the design of the Central Subway Chinatown Station.

The Central Subway Project has achieved major milestones in recent months, and more progress is on the horizon this year:

• The contract for the Chinatown Station has been advertised. Bids on the estimated $235 million contract are due May 8.
• Contracts for the other three Central Subway stations are on track for advertisement this spring and summer.
• Work to prepare the project alignment for the construction of a 1.6-mile tunnel is on track to commence this spring.
• In his budget proposal for fiscal year 2013, President Obama included a recommendation for $150 million in funding for the Central Subway Project.
• For the fifth consecutive year, the project received a strong positive rating from the Federal Transit Administration in its annual New Starts review. This indicates that a Full Funding Grant Agreement for nearly $1 billion in New Starts funding may be forthcoming.

To find out more about the Chinatown Station and recent progress on the Central Subway Project, check out this press release (PDF) from Mayor Lee’s office.

Please click the thumbnail image below to view the PDF.

Central Subway Poll Results

SFMTA Director Ed Reiskin and Central Subway Program Director John Funghi lead the press conference

MTA director Ed Reiskin joined Central Subway Program Director John Funghi and Central Subway supporters, including David Nadelman, president of the Union Square Business District, and Jim Lazarus, senior vice president of the San Francisco Chamber of Commerce, to highlight progress made on the project and to announce $20 million in New Starts funds from the federal government.  Several articles have been published by local media about the announcement which are linked below, and a Press Release from the SFMTA is available as well.

SF Gate: Defending the Central Subway

CBS San Francisco: Influx Of Money To San Francisco Central Subway Project

SF Appeal: Transit Officials, Business Leaders Say Central Subway Is On Track To Secure Final Federal Funding