As reported in September, beginning Monday BART will start service an hour later in the morning—rolling out at 5 a.m. instead of 4 a.m.—and put trains on a slower, single-track schedule after 9 p.m.
The schedule changes are part of a four-year, $313-million plan to strengthen the Transbay Tube against the possibility of flooding during a catastrophic earthquake.
BART gave some details in an email to riders Thursday:
We are preparing for a rare and devastating earthquake- defined as a 1,000 year event- something that happens once every thousand years. In an event this large, the tube [...] could crack and leak.
The retrofit we are about to carry out will install [...] an upgraded pumping system to allow larger quantities of water to be removed quickly from the tube.
A plate handling machine will maneuver sections of curved steel plates to form archways inside the tube. Once put in place they will be welded together and bolted into place. Grout will then be used to adhere the steel plates to the concrete walls.
The later 5 a.m. start times mean the first East Bay trains will arrive in San Francisco at around 5:30 a.m.
BART also warns of a number of other potential schedule squeezes, including:
- On weeknights after 9 p.m., trains will run every 24 minutes instead of every 20 minutes. The delay is on account of single-tracking through the tube.
- “The first train from Daly City (5:03 am) to Antioch will skip from MacArthur directly to Pittsburg/Bay Point. The train will not pick up or drop off passengers between these stations.”
- On Sundays, “For the most part only one line (the Antioch/Yellow Line) will provide service through the Transbay Tube.”
- Also on Sundays, “Dublin/Pleasanton/Blue Line service will operate [only] between Dublin/Pleasanton and MacArthur.”
Saturday is the only day of the week with no planned schedule changes.
Under the current time line, Shimmick Construction (the same company that worked on the near disastrous Twin Peaks Tunnel retrofit, although BART hired the company years before those incidents) will finish the tube work in 2023.