San Francisco’s Central Subway is getting closer to completion

A man secures large yellow tarps as part of a waterproofing procedure during construction on the Central Subway near Stockton and Washington streets Tuesday, April 3, 2018 in San Francisco, Calif. A man secures large yellow tarps as part of a waterproofing procedure during construction on the Central Subway near Stockton and Washington streets Tuesday, April 3, 2018 in San Francisco, Calif. Photo: Jessica Christian / The Chronicle Buy photo Photo: Jessica Christian / The Chronicle Image 1 of / 18 Caption Close San Francisco’s Central Subway is getting closer to completion 1 / 18 Back to Gallery

A dozen stories beneath Stockton Street in San Francisco’s Chinatown, the digging is done, and the final station for Muni’s $1.6 billion Central Subway is beginning to rise toward the street.

Muni officials on Tuesday announced the end of excavation and said the Central Subway is on track to begin taking on passengers by December 2019.

The subway, a 1.7-mile extension of Muni’s T-Third line, was originally projected to open by the end of this year. But troubles with the underground excavation of the Chinatown station at Washington Street — using mining techniques to keep the street open — slowed construction.

The opening date for the subway has been a point of dispute. An independent monitor has projected the opening by the end of 2019 in recent reports, but subway contractor Tutor Perini told members of the Board of Supervisors in December that opening might be delayed to 2021.

Standing where the tracks will pass through the Chinatown station, Ed Reiskin, the MTA’s transportation director, said the end of excavation was a significant milestone and that the project is moving ahead.

“We’re holding with the December 2019 projection,” he said. Representatives of Tutor did not respond to a request for comment Tuesday.

As Reiskin spoke, dozens of workers hustled around the cavern, installing waterproofing on the walls and rebar on the floors.

Acting Project Manager Albert Hoe said the next steps involve pouring the subway floor and installing the station entrances and concourse, the tracks, and electrical and mechanical systems. He said he expects those to be completed by the middle of 2019. Then Muni will take over and start testing and training.

Neighbors of the Chinatown station will welcome the winding down of construction, which has disrupted business and traffic, even though Stockton Street remained open.

Cheryl Brinkman, chairwoman of the MTA Board of Directors, said delays are unfortunately common on major infrastructure projects, especially in dense urban areas. But she said she hopes the opening of the subway will bring new business and vitality to the neighborhood as well as providing better mobility for people who now have to crowd aboard sluggish Muni buses.

“I hope they feel that will make up for the years of impact,” she said.

Elsewhere along the Central Subway line, progress is also being made, Hoe said. Subterranean stations at Yerba Buena/Moscone Center and Union Square should be completed by the end of the year.

Mayor Mark Farrell, who toured the station Tuesday, said it was “awe-inspiring to be down here” and pronounced it “the future of San Francisco.” He also supported a future extension of the subway.

“We need to be digging not just to North Beach but beyond,” he said.