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Workers buzzed in a hive of activity last Friday night in the tunnel underground the 16th St./Mission BART Station as crews reached a major milestone in an important infrastructure improvement: large-scale installation of modern and robust high-voltage cables to reliably run trains.

When it’s all done, BART riders can expect a more resilient electrical power system to handle more frequent trains and support the growing number of Fleet of the Future trains.

The operation involved pulling three large cables through a conduit using a mechanical cable puller, part of an upgrade funded by the Measure RR bond that voters approved in 2016. The existing electrical system is from when BART was built in the 1960s.
 

Cable rail truck with 3,000 feet of cable being transported

The first task in a cable replacement project is to install new 6-inch phenolic (a thermosetting resin) conduits. These conduits are attached to the ceiling of the tunnels using high grade structural steel plates and clamps.  

Crew setting cable and steel braided line in pulling guide

BART is using a new type of conduit that is lightweight, strong and durable. Benefits to these new types of conduit include less time to install, lower maintenance cost and longer service life. The second task is to insert a steel braided line into the entire length of conduit, ensuring the conduit is clear of obstructions and ready for the cable pull.

As soon as the steel braided line is pulled through the entire conduit, one end is attached to the electrical cables and the other end is connected to the mechanical cable puller.

A journeyman electrician attaches cable pulling guides to the steel ring of the tunnel using high-strength structural steel.

Now the cable pulling operation can begin. The seafoam green mechanical cable puller slowly pulls the cable into the lubricated conduit. It measures pulling tension every second to ensure no damage to the cable or conduit. It takes about one hour for the cable to travel through the entire length of the conduit. As the cable snaked along, workers listened for the sounds of its progress through the conduit.
 

An electrician attaching the steel braided line to the start of the cable pull

Once the cable reaches the mechanical cable puller end, all the cable is inside the conduit and the cable pull is accomplished. It may sound simple, but the workers face challenging conditions in the dark, cramped underground space. Large fans blow fresh air – required for workers to safely breathe -- into the tunnel.

BART’s infrastructure and system upgrades is considered essential work and thus can continue under the coronavirus shelter-in-place orders. Workers are equipped with face masks, safety glasses, hard hats and other PPE, and keep the greatest social distance possible on each job.

Managers watching work on cable pull operation

The additional time made available by BART’s 9 pm early closure, due to low ridership during the pandemic and in effect until further notice, is being used to ramp up projects like the electrical system upgrade.

Customers may be affected by the need to single-track for this project; the extra time is necessary to bring in staff and materials to be ready to go when trains stop running. This time means, potentially, we will be able to perform three cable pulls instead of one per shift. That equals up to 9,200 linear feet (or nearly 2 miles) of cable that can be installed each night. This could shave off many months of work affecting our customers from the five-year-long project

DMZ Builders, a local general engineering contractor based in Concord, is the contractor for the project.

On Thursday, October 24, 2024, California Secretary of Transportation Toks Omishakin announced at the North Berkeley BART Station that BART has been awarded $25 million from the Cycle 7 Transit and Intercity Rail Capital Program (TIRCP) for the North Berkeley Transit-Oriented Development (TOD) Mobility Enhancements Project. 

“This funding makes possible two plazas plus bike and pedestrian improvements, which will help transform the North Berkeley BART station area into a mixed-use, sustainable community,” says BART Board Director Rebecca Saltzman, who represents the station. “By enhancing access to public transit and improving bike and pedestrian infrastructure, projects like this will reduce dependency on personal vehicles.” 

Key project components include BART rider parking within a TOD garage, publicly accessible open spaces including an intermodal transit plaza, and walking and biking enhancements around the station. The TOD will transform the main North Berkeley Station parking lot into housing and open space. The TIRCP funds are critical to supporting investments that enhance access to BART for current and future BART riders.  

TIRCP funds will be used to enhance walking and biking infrastructure and augment multimodal connections. These enhancements are expected to boost ridership by facilitating safe pedestrian and bike access and promoting non-automotive transportation. The estimated total cost for the Mobility Enhancements Project is $37 million. Remaining funding sources are from local and state contributions.

The overall North Berkeley Station TOD project prioritizes affordable housing, aligns with BART’s TOD Policy goals and meets the strategic objectives of the TIRCP program.  The project will consist of five residential buildings that will be built in phases. 

BART estimates that the 739 new homes in the TOD, with approximately half affordable for households at or below 80% of Area Median Income, would generate roughly 750 new trips per day by 2031.