Central Subway Project Manager John Funghi leads Mayor Edwin Lee on a tour of the completed tunnels

Congratulations to the Central Subway Team for achieving an Award of Merit for best transportation project of 2015 from Engineering News record, a weekly magazine highlighting the construction industry. The award was given for the completion of the Central Subway Tunnel. The Central Subway Tunnel Project was cited for completing an intricate project on time and within the approved budget.

A method called deep tunneling was used to build the tunnels. Two tunnel boring machines, named for San Francisco Legends Alma Spreckels and Dr. Margaret “Mom” Chung, were used in the construction. Use of these machines enabled the work to be finished with less surface disruptions and reduced utility relocations.

The Central Subway Tunnel completion was a major milestone for the project. When the Central Subway is completed, T Third Line trains will travel mostly underground in the 2 mile tunnels from 4th Street to Chinatown, bypassing heavy traffic on congested 4th and Stockton Streets. Our team is very proud to have been recognized by ENR for this achievement.

The Central Subway Team looks forward to more success in 2016. We wish San Francisco a very happy and healthy holiday season.

For more information on this honor see http://www.enr.com/articles/38039-airporttransit-award-of-merit-central-subway-tunnel.

Below are some photos of the project.

Former Mayor Gavin Newsom and former District 3 Supervisor David Chiu join other local dignitaries at the Central Subway groundbreaking ceremony in February, 2010

Two workers install utility conduits following the completion of new section of tunnel

The cutterheads of both tunnel boring machines can be seen following the completion of the twin tunnels of the Central Subway

The twin tunnels are made up of precast concrete rings comprised of six segments, which are bolted together underground.  Next steps for the Project include installation of track and systems to get revenue service ready by 2019.

Local and network media participated in a news conference earlier this week to see the completed tunnels firsthand.

Read here for more about the event.

Their trek was commemorated in different ways:

San Francisco Mayor Ed Lee toured the beginnings of the tunneling project.

The Mayor signed Tunnel Boring Machine Mom Chung at the onset of her 1.7 mile journey across San Francisco.

Last year, the two TBMs completed their journey under the streets of San Francisco.  Staff poses at the completed end point known as the retrieval shaft.

View of the tunnel portal ramp from 4th and Stillman during construction of the portal walls, which will separate automobile traffic from light rail vehicles.

Workers put up temporary bracing while they pour concrete for the tunnel portal walls at 4th and Perry Alley.

The video shows TBM Mom Chung breaking into the water-filled retrieval shaft last June. The water is drained from the shaft for the arrival of TBM Big Alma. The departure of the machines comes next as workers remove both TBMs, piece by piece, over several months. The retrieval shaft site was restored and vacated in January 2015.

A metal cover was installed as the final step in restoring the site.

For more information about the project and construction progress, follow us on Facebook, Twitter, Flickr, YouTube and check out our project website.

This rendering shows what the portal may look like upon completion.

The portal will bring the light rail vehicles to the surface and vice-versa, thereby connecting the north and south quadrants of the city. The construction of the portal includes building walls, a floor/ramp and back filling the area. The walls and floor are being strengthened by inserting metal re-bar into the structure.

The floor of the portal is gradually being built into a ramp.

The portal walls are being reinforced with re-bar.

 Metal bracing is being installed to support the walls.

Visible surface construction activity for the portal will be seen in December. The portal is estimated to be completed by the 2nd quarter of 2015.

The cutter head of tunnel boring machine (TBM) Mom Chung can be seen in the background as workers disassemble the shield of TBM Big Alma.

During the next 10 days, Central Subway work continues at sites in SoMa, Union Square, Chinatown and North Beach. This section contains brief updates about what is happening in each neighborhood. For more detailed information click here or on the links below. You can also find construction, traffic detour, and Muni impact information on our project Google Map. For safety reasons, we encourage the public to follow all traffic and pedestrian notifications posted at the work sites.

Southern SoMa (Harrison to King/Berry): Potholing for utilities continues next week on 4th Street between Bryant and King. On Brannan between 4th and 5th Streets, work on utilities continues. Temporary walkways are in place around the construction zones.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This includes construction of the station walls within the work site and water line replacement at the intersection of 4th and Folsom. Until Monday, July 28, 4th Street from Howard to Folsom streets will have one traffic lane. This area will continue to have a lane reduction overnight from 7 p.m. to 5 a.m.

Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic to allow for construction of the Union Square/Market Street Station. Work is underway for pile installation to construct the station walls. For the month of July, Stockton Street between Post and Geary will be closed to vehicular traffic. Please use alternate routes and follow construction signs.

Pile installation takes place at the southwest intersection of Stockton and O’Farrell streets until August 18. One lane of travel will be open. Expect delays and please use alternative routes.

Muni service impact:
Until August 1, the bus stop at Geary and Stockton will be temporarily discontinued. Please board bus at Geary and Powell. Please check back on our weekly Construction Update for the most current information on the re-opening of this stop.

Chinatown:  The contractor started station wall construction at the future station site and on the adjacent section of Washington Street. Work to replace high pressure water pipeline and install new fire hydrant on Washington is ongoing. A section of the sidewalk at the northeast corner of the Washington and Stockton intersection will be demolished in order to install a new fire hydrant.

North Beach: Work continues at 1731-1741 Powell. Sustainable Streets is constructing bulbs on Columbus Avenue between Filbert and Union streets, and widening the sidewalk on both sides of the street for this block. Street restoration work is expected to be completed by the end of August. More information is available in this notice.

We thank the businesses, residents, shoppers, and commuters of San Francisco for their continued engagement with this significant investment in the extension of our public transportation system.

The entrances to both subway tunnels can be seen here in the TBM launch box under 4th Street, near Harrison.

During the next 10 days, Central Subway work will continue at sites in SoMa, Union Square, Chinatown and North Beach. This post contains brief updates about what is happening in each neighborhood. For more detailed information, click here or on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Southern SoMa (Harrison to King/Berry): Potholing for utilities will continue next week on 4th Street between Bryant and King. Hydrant relocation work to occur at 4th and Bryant. A temporary walkway is in place around the construction zones. Street sweeping on June 23rd  (6am to 10am) on 4th Street from Bryant to Brannan along the west side of 4th Street and at the corner of Brannan.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This includes construction of the station walls within the work site, water line replacement at the intersection of 4th and Folsom, and soil borings along 4th between Howard and Folsom.

Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic and partial closure to vehicular traffic between Geary to Post to allow for construction of the Union Square/Market Street Station. Work is underway for pile installation to construct the station walls. Construction hours will be Monday to Saturday from 7 a.m. to 11 p.m. Beginning May 30 to July 25, the bus stop at Geary and Stockton will be temporarily closed every Friday at 10 p.m. through the weekend. Service will resume every Monday at 4 a.m. One lane of traffic on O’Farrell Street at Stockton will start on Monday June 23rd. All travel lanes will be reopened by 4 a.m. on Wednesday, June 25th.

Chinatown:  The contractor has started station wall construction within the future station site and on the adjacent section of Washington Street.

North Beach: Work will continue at 1455 Stockton and 1731-1741 Powell. Sustainable Streets is constructing bulbs on Columbus Avenue between Filbert and Union Streets, and widening the sidewalk on both sides of the street for this block. Street restoration work is expected to be completed by the 3rd Quarter of 2014. More information is available in this notice.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.

On Wednesday, June 11, tunnel boring machine Big Alma joined her sister TBM Mom Chung to break through the concrete wall of the North Beach retrieval shaft.

During the next 10 days, Central Subway work will continue at sites in SoMa, Union Square, Chinatown and North Beach. This section contains brief updates about what is happening in each neighborhood. For more detailed information, click here or on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Southern SoMa (Harrison to King/Berry): Potholing for utilities will continue next week on 4th Street between Bryant and King. A temporary walkway is in place around the construction zone.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This will include construction of the station walls within the work site and water line replacement at the intersection Fourth and Folsom. Night work is planned for these activities.

Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic and partial closure to vehicular traffic between Geary to Post to allow for construction of the Union Square/Market Street Station. Work is underway for pile installation to construct the station walls. Construction hours will be Monday to Saturday from 7 a.m. to 11 p.m. Beginning May 30 to July 25, the bus stop at Geary and Stockton will be temporarily be closed every Friday at 10 p.m. through the weekend. Service will resume every Monday at 4a.m. Muni service for this location will temporarily stop Mondays through Thursdays from 8 p.m. to 4 a.m.

Chinatown:  The contractor has started station wall construction within the future station site and on the adjacent section of Washington Street.

North Beach: Work will continue at 1455 Stockton and 1731-1741 Powell. Roadway and sidewalk restoration on Columbus and Union will continue and is expected to be completed by the 3^rd quarter of 2014.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.

-The Central Subway Team