Rail

San Francisco tunnel boring continues progress

Posted on January 29, 2014

The San Francisco Municipal Transportation Agency (SFMTA) announced the Central Subway’s second tunnel boring machine (TBM) will soon pass beneath existing Bay Area Rapid Transit District (BART) and Muni Metro tunnels, while passing under Market Street from SoMa into Union Square.

When the Central Subway opens, the new tunnels will allow T Third Line trains to cut travel times by more than half along this busy corridor.

The SFMTA has worked in close coordination with BART and an independent panel of top tunneling experts to plan and carry out this key phase of tunnel construction. To pass beneath Market Street and the existing transit tunnels, TBM Big Alma will turn slightly left beneath 4th Street just south of Market Street. The machine will then veer right to head north under Market Street and then Stockton Street. The new T Third Line tunnels will be about 10 feet below the existing BART tunnels.

Beginning Tuesday, Big Alma was set to be in operation 24 hours a day to build the approximately 425 feet of new tunnel beneath the Market Street tunnels. Late last year the first TBM, called Mom Chung, safely and successfully completed the same undercrossing, using the same techniques and interagency coordination. Mom Chung is now beginning to tunnel under Nob Hill, heading toward Chinatown.

Including both tunnels, tunneling contractor Barnard Impregilo Healy (BIH) has constructed more than 6,900 feet of tunnel under 4th Street and Stockton Street so far.

The crossing under BART may last up to six days, with the tunneling also possibly causing BART to run at slower speeds in the area.

View comments or post a comment on this story. (0 Comments)

More News

Back doors of MUNI trains to remain closed until investigation complete

A woman got her hand stuck in a closed door of one of the new MUNI light rail vehicles before falling down onto the track.

Amtrak service rolls out cleaner Siemens diesel-electric locomotives

The new Charger is the first passenger locomotive to receive the stringent Tier IV emissions certification from the EPA.

Shuttered NJ TRANSIT rail services to be restored before target

The new date is nearly two weeks ahead of the agency’s target date.

NHTSA, FRA launch rail crossing safety campaign

In 2018 alone, 270 people were killed at railroad crossings.

San Diego MTS unveils 5000-series Siemens Trolley cars

The new vehicles represent the third generation of modern, low-floor vehicles, which have been in operation since 2005.

See More News

Post a Comment

Post Comment

Comments (0)

More From The World's Largest Fleet Publisher

Automotive Fleet

The Car and truck fleet and leasing management magazine

Business Fleet

managing 10-50 company vehicles

Fleet Financials

Executive vehicle management

Government Fleet

managing public sector vehicles & equipment

TruckingInfo.com

THE COMMERCIAL TRUCK INDUSTRY’S MOST IN-DEPTH INFORMATION SOURCE

Work Truck Magazine

The number 1 resource for vocational truck fleets

Schoolbus Fleet

Serving school transportation professionals in the U.S. and Canada

LCT Magazine

Global Resource For Limousine and Bus Transportation