Original news was published on 27 June, 2014

Central Subway project on time for 2019 opening

The digging is over at San Francisco’s first new subway in nearly 50 years. Tunnel boring machines Mom Chung and Big Alma have completed tunnelling for the US$1.6 billion Central Subway project in San Francisco, Calif.

“Building these subway tunnels under a city that’s been well established since the “Gold Rush” of the 1800s has meant confronting plenty of structural and historical challenges underground in addition to the soft ground and hard rock soil conditions,” Barnard Construction said in a statement. Barnard, based in Montana, formed a joint venture with Italy’s Impregilo and S. A. Healy Company and won the construction contract in 2012 from the S.F. Municipal Transportation Agency.

The TBMs each tunnelled 2.6 kilometers to build two new subway tunnels connecting SoMa (south of Market Street), Union Square and Chinatown. Mom Chung completed its tunnel in 11 months; Alma in just 8-½ months. Both machines were built by Robinson Company.

To minimize disruption to city traffic and businesses, the TBM launch box was built under an I-80 overpass and potentially disruptive work was scheduled at night. The TBMs will now be removed and refurbished for future jobs.

The Central Subway will open in 2019.


*NEWS SOURCE