After about eight and a half months of boring, Big Alma emerged to much fanfare in San Francisco's North Beach neighborhood. The San Francisco Examiner's Jessica Kwong was there to record the 'breakthrough' event, as she was for three other key tunnel-boring dates (see those articles under "related links") for the city's new Central Subway.
“It’s like giving birth,” said John Fungi, the San Francisco Municipal Transportation Agency’s Central Subway program director, with a chuckle.
Seattle's Alaskan Way Viaduct project put Big Bertha to work to bore "a two-mile-long, $3.1 billion highway tunnel under the city’s waterfront" (per NYT). Bertha ground to a halt last December after she hit "an object" and is still "stuck in the mud."
If Seattle is suffering boring machine envy, you'd have to "double it" because Big Alma is not San Francisco's only borer. There's Mom Chung (the Central Subway does to to Chinatown, after all) that began excavating last July and emerged on June 2.
While the Central Subway's engineering has proven to be successful to-date, the project suffered through a long history of "uncertain funding and local opposition."