Tunnel Project FAQs

What is the Tunnel Project?

There are four tunnels between Caltrain's San Francisco terminal and Bayshore station. Although the tunnels have withstood some of the Bay Area's most fierce quakes and tremors, they were built in 1906 and require reinforcement as the system changes and modernizes. Each of Caltrain's some 500 weekly trains must pass through all tunnels making it critical that the tunnels be seismically sound. Caltrain construction crews are doing just that by reinforcing the Tunnels with 3,400 cubic yards of shotcrete, a mixture of cement, sand, and steel fiber. In addition, the ceiling of one of the four tunnels is being treated with grout, a mixture of sand and cement to be inserted into 1,200 newly drilled holes.

What is the project schedule?

Work on the two southern tunnels, located near Caltrain's Paul Avenue and Bayshore stations, began in August 2004 and is scheduled to finish by February 2005. Work on the two northern tunnels, located between 18th and 25th streets in San Francisco, is scheduled to take place between February and June 2005.

What are the project's hours?

Construction crews work Tuesdays through Sundays 8:30 p.m. to 4:30 a.m. Crews had been working Wednesdays through Sundays, but recently an additional day was added to keep the project on schedule.

Why does the work take place at night?

In order to avoid significant impacts to Caltrain's passengers, Caltrain work crews must complete their work when the train schedule is at its lightest and overnight when there is no passenger service.

Where does the work take place?

The majority of the work takes place at the tunnels. The two southern tunnels are located between Caltrain's Paul Avenue and Bayshore stations. The two northern tunnels are located between 18th and 25th streets in San Francisco. Because the project requires lots of heavy equipment and materials, construction crews must have a location to mobilize and perform preparatory work. For work on the Bayshore tunnel, crews are mobilizing near the Brisbane Fire station. For work on all other tunnels, crews are mobilizing in San Francisco on Carroll Avenue and Third Street.

What has been making so much noise?

Caltrain is using track mobiles to move heavy equipment and materials up and down the tracks. Heavy loads add strain to the track mobile's motor, causing some noise while it is making a move. One track mobile operates between the Brisbane fire station and the Bayshore Caltrain Station to the north. The other track mobile operates in San Francisco between Carroll and Third streets and the Paul Street station. When work begins in February on the two northern tunnels, the track mobiles will move between Carroll Avenue and Third Street and 18th Street in San Francisco.

What has Caltrain done to lessen the noise?

In response to concerns from our Brisbane neighbors, Caltrain added mufflers to both track mobiles in early December.