Construction Update
October 5-14, 2013
During the next 10 days, tunneling and tunneling preparatory work will continue in SoMa, Union Square and North Beach. Work to prepare for station construction is continuing in Chinatown and northern SoMa.
For descriptions of construction impacts in each neighborhood, scroll down or click on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.
Construction impacts are planned to change at these locations by October 14:
- Northern SoMa (Market to Harrison): All lanes are now open to traffic on 4th Street between Market and Stevenson. On 4th Street between Folsom and Harrison, the parking lane and one lane of traffic on the east side of the street will remain closed to allow for ground improvement work. On 4th Street between Howard and Folsom, one lane will remain closed to traffic south of Clementina. Demolition of the 76 gas station in progress.
- Chinatown: In Chinatown, work to prepare for station construction will continue. The turn lane from Stockton Street onto Washington Street may be closed for one day next week. Several parking spaces will be closed near the intersection of Stockton and Washington and adjacent to the future Chinatown Station site 9933-949 Stockton). The sidewalk adjacent to the building will remain closed to pedestrians.
At these locations, current construction impacts are planned to continue until
October 14:
- Southern SoMa (Harrison to King/Berry): 4th Street between Harrison and Bryant may fully close some evenings and weekends to allow for the installation of tunneling components and piping. Two lanes of traffic will remain open at all other times. Contact us at central.subway@sfmta.com if you have questions about the closure schedule. On Bryant Street at 5th Street, the left lane and several parking spaces will remain closed. One lane of the I-80 off ramp at 4th and Bryant may be closed at times to allow for utility work.
- Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
- North Beach: Construction of a retrieval shaft, to be used to remove two tunnel boring machines, is commencing at the Pagoda Palace site. Crews are installing monitoring instruments and building a sound wall that will buffer construction noise. Construction hours are Monday to Saturday, 7 a.m. to 7 p.m. All local roadways will remain open. Parking and walkways may be impacted in front of the Pagoda Palace property.
We appreciate your patience and support while we build this essential upgrade to San Francisco's public transportation system.
-The Central Subway Team 
The back of TBM Big Alma, called the trailing gear, is now assembled. Crews are now testing the machine and preparing it for launch. Southern SoMa
4th Street from Harrison to King/Berry
On 4th Street between Harrison and Bryant streets, the contractor has constructed a major excavation known as a launch box at the site where the Central Subway tunnel begins. After assembly of a tunnel boring machine (TBM) underground, tunneling started this summer. Assembly of a second TBM (Big Alma) is now in progress.
Planned construction:
- Construct tunnel for southbound trains (TBM Mom Chung)
- Test and commission TBM Big Alma
Traffic and pedestrian impacts:
- The two lanes on the east side of the street (left lanes for southbound traffic) will remain open to vehicle traffic except as described below.
- The block may close to traffic from 8 p.m. to 5:30 a.m. on weeknights and all day Saturday and Sunday.
- The sidewalk on the west side of the block will remain closed; the sidewalk on the east side of the block will remain open.
- On Bryant Street at 5th Street, the left lane and several parking spaces will be closed.
- One lane of the I-80 off ramp at 4th and Bryant may be closed to allow for utility work.
Traffic and pedestrian controls are in place. For more information on construction impacts at this site, check out this blog post.
Work has recommenced on 4th Street at Harrison. We will improve ground conditions here to protect the area when the tunnel boring machines pass beneath.
Northern SoMa
4th Street from Market to Harrison
On 4th Street between Howard and Folsom streets, preparatory work to construct the Yerba Buena/Moscone Station is now in progress at the corner of 4th and Folsom, within the site of the old 76 gas station.
The contractor completed ground improvement work (installation of compensation grout tubes) on 4th Street between Market and Stevenson. Work will resume when the tunnel boring machines pass through this area, approximately late October.
On 4th Street between Folsom and Harrison, the contractor will perform ground improvements while the tunnel boring machines pass beneath the roadway.
Planned construction (Market to Stevenson):
- No work planned
- Construction will resume when the tunnel boring machines pass beneath this area (approx. late October)
Traffic and pedestrian impacts (Market to Stevenson):
- None planned
Planned construction (Howard to Folsom):
- Abate hazardous materials at 260-266 4th Street (former 76 gas station site)
- The contractor may begin demolishing the 76 gas station
Traffic and pedestrian impacts (Howard to Folsom):
- South of Clementina, one lane of traffic will be closed on the east side of the roadway, next to the turning lane
Planned construction (Folsom to Harrison):
- Set up ground improvement equipment
- Inject grout to improve ground conditions
Traffic and pedestrian impacts (Folsom to Harrison):
- The parking lane and one lane of traffic on the eastern side of the street (in front of Whole Foods) will be closed
Work continues on Stockton Street, the site of the future Union Square/Market Street Station. Union Square
Stockton Street from Market to Post
On Stockton Street between Geary and Ellis streets, the contractor is installing below-ground walls called headwalls at the site of the future Union Square/Market Street Station. In addition, ground improvement is underway on Ellis Street between Stockton and Powell streets.
Planned construction:
- Stockton between Ellis and O'Farrell: The current phase of construction is complete on this block. Restoration is expected to start by the end of October.
- Stockton between O'Farrell and Geary: Install headwalls
- Ellis between Stockton and Powell: Perform ground improvements from inside the Ellis Street shaft
- On Stockton Street, the contractor will continue working two shifts on weekdays, from 6 a.m. to 12:30 a.m. On Saturdays, work hours will be 6 a.m. to 12:30 a.m.
- On Ellis Street, the contractor will work 24 hours a day on weekdays
Traffic, transit and pedestrian impacts:
- Stockton Street between Geary and Ellis is closed to all vehicles except emergency vehicles
- Ellis Street between Stockton and the Ellis-O'Farrell Garage (between Stockton and Powell) is closed to westbound traffic
- The 38/38L Geary may experience delays around Union Square
- Sidewalks on Stockton Street between Ellis and Geary will remain open, but they may be narrowed to facilitate construction
More information about construction at this site is available in this construction notice and this press release. 
At a recent community meeting, Central Subway team members answer questions about Chinatown Station construction. Chinatown
Stockton Street from Sacramento to Broadway
To prepare to build the Chinatown Station, contractor Tutor Perini will demolish the existing building at 933-949 Stockton Street. Preparatory construction is now underway.
Planned construction:
- Remove hazardous materials
- Install instruments
- Cap utility lines (some work in street)
- Pothole for utilities. This work will take place Oct. 8-11. On Stockton Street, work hours are from 9 a.m. to 3 p.m. On other streets, work will start at 7 a.m., ending at 3 p.m.
Traffic, transit and pedestrian impacts:
- Several parking spaces may be closed near the intersection of Stockton and Washington, on both streets
- The sidewalks in front of the building on Stockton and Washington streets will remain closed
- The turn lane from Stockton Street onto Washington Street may be closed
This wall, called a sound wall, will buffer construction noise during the next phase of work at the Pagoda Palace in North Beach. North Beach
Powell Street from Union to Columbus
On private property at 1731-1741 Powell Street, the contractor is preparing to construct a walled excavation known as a retrieval shaft at the site where tunneling will end. The two tunnel boring machines will be removed from the ground at this location.
Demolition of the Pagoda Palace is now complete. The second phase of construction is to construct the retrieval shaft.
Planned construction:
- Install monitoring instruments
- Construct sound wall to mitigate construction noise
- Prepare site for retrieval shaft construction
- Construction hours for the retrieval shaft are Monday to Saturday, 7 a.m. to 7 p.m.
Traffic, transit and pedestrian impacts:
- Several parking spaces may be closed in front of the property during construction hours.
- The sidewalk in front of the property may be closed. A temporary walkway will be in place around the construction zone when the sidewalk is closed.
Central Subway Construction Fast Facts
Project Alignment: 4th Street between Berry and Market streets; Stockton Street between Market Street and Columbus Avenue; Powell Street between Union Street and Columbus Avenue; Columbus Avenue between Powell and Filbert streets.
Transit Reroutes: The southbound 8X/8AX/8BX Bayshore Express, 30 Stockton, 45 Union/Stockton and 91 Owl Muni bus routes have been rerouted to accommodate construction in Union Square and SoMa. These reroutes will remain in effect throughout the duration of Central Subway construction. More information is available online here.
Contact Us: Should you have questions about construction or the Central Subway Project, don't hesitate to contact our team. You can reach us at central.subway@sfmta.com or by phone at 415-701-4371.
For More Information: The Central Subway team posts frequent project updates on a variety of social media outlets. To find out more about the project and construction progress, follow us on Facebook, Twitter, Instagram or Flickr, and check out our blog.
Construction schedules are subject to change.