From BART General Manager Grace Crunican
On December 1, the San Francisco Bay Area Rapid Transit District (BART) Board of Directors authorized me to award a $267 million contract for the BART Earthquake Safety Program (ESP) Transbay Tube (TBT) Internal Retrofit.
The TBT is one of BART’s most critical assets. Although the tube is structurally sound, in a very large and very rare earthquake event, the outer shell and concrete liner are predicted to crack, causing leakage. The retrofit would address concerns of flooding in the event of a 1,000 year earthquake through the installation of internal lining to portions of the TBT, as well as construction of a new pumping system.
Beginning in July 2018, work will be performed at night, Sunday through Thursday; and early mornings, Monday through Friday. In order to extend the current available work window by 20%, BART plans to open the entire system one hour later on weekdays, changing from a 4:00 am to a 5:00 am opening time for a period of up to 2.5 years.
Five proposed early morning mitigation concepts were presented to the BART Board of Directors, and in the coming months, BART staff will develop an outreach plan to seek public input. Once the outreach and impact analysis are completed, the BART Board will review then officially adopt a mitigation plan, determining any service changes to go into effect July 2018.