Issue 548 to

Exploring the Central Subway Tunnel.

Urban Field Notes: Notes from Underground

Touring the Future Central Subway

Urbanist Article

This past September I was lucky enough to tour the Central Subway tunnel ... but just unlucky enough to have missed an up-close and personal moment with the two massive tunnel boring machines (TBMs) that had been used to excavate and construct them. As is common practice, the tunnels were named to bring the project good luck: Mom Chung and Big Alma (two famous San Francisco women, the former a doctor, the latter a socialite whose marriage to sugar magnate Adolph Spreckels blessed our culture with the term “Sugar Daddy”). In 2014, Mom Chung had set to work on the tunnel for southbound trains, Big Alma the north, each digging at an average rate of about 40 feet of tunnel per day.

Even though the TBMs had left the station just days before and were en route to Russia for a new project, there was plenty to experience underground. Track had not yet been laid so the tunnel was a cool, utterly pristine passageway; it was wild to imagine the transformation that will be taking place there over the next several years. San Francisco’s population has been growing by 10,000 people per year and is projected to add another 150,000 residents by 2040. Transit has not kept pace, so it’s a big deal that this project will serve 90,000 riders daily. The Central Subway is scheduled for completion in 2019.

I'm still a bit sad that I missed seeing the tunnel boring machines.

 

This is what the tunnel entrance looked like days after completion. Mom Chung dug the tunnel on the left; Big Alma, the one on the right. SFMTA started laying track a few days later.

 

rat

While not as impressive as the New York's subway's Pizza Rat, a visit to the under-construction subway would have felt incomplete with a rodent sighting.

 

I was joined on the tour by Tim Hwang, founder of the Bay Area Infrastructure Observatory. Tim is so infrastructure-obsessed that he toured the Silicon Valley Advanced Water Purification Center in San Jose the very next day.

 

I will own up to looking ridiculously dorky as I walked six blocks above ground, wearing a hard hat, protective glasses and a Day-Glo Vest en route to the tunnel entrance at Fourth and Brannan

 

Special thanks to John Funghi and his crew at the SFMTA for keeping us safe and on track.

 

Allison Arieff is SPUR's editorial director.