SAN FRANCISCO (KCBS) – Tunneling work for the Central Subway project in San Francisco is set to begin in the coming weeks, with the underground work beginning at 4th and Harrison streets.

San Francisco Mayor Ed Lee, at a tour and celebration of the project on Thursday, said the tunnel boring machine is in place and ready to do the digging.

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“There’s a lot of growth that is happening in our southeast corridor and they want to connect up with the northeast corridor,” Lee said. “This is our future, this is what we’ve been talking about and it’s right here before us.”

The machine will bore a tunnel for the first major extension for the Muni Metro T line through South of Market, Union Square and Chinatown.

Ed Reiskin, Director of Transportation of the San Francisco Municipal Transportation Agency, said the digging will begin on June 10.

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“This is the first of two that will be making its way from here, underneath BART, underneath Chinatown and up into North Beach,” he said. “The second one will follow a few months later.” The machines are 350 feet long.

The machine in place now is called Mom Chung, named for Dr. Margaret Chung, the nation’s first female Chinese-American physician.

The second boring machine will be called Big Alma, after Alma de Bretteville Spreckels, a wealthy socialite and philanthropist. Among her many accomplishments, she persuaded her first husband, sugar magnate Adolph B. Spreckels, to fund the design and construction of the California Palace of the Legion of Honor at Lands End.

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