The transformation of San Francisco’s historic Pier 70 shipyard into shops, offices and housing comes with a heavy lift.
The 4.5-million-pound Building 12, where workers toiled during World War II to build metal ship plates, had to be guarded against a different threat: rising seas. Developer Brookfield Properties needed to lift the structure 10 feet, shielding it from the anticipated effects of climate change through 2100.
Preparation took nine months, including digging down 8 feet for new elevator pits and the construction of a new foundation. Brookfield worked with Plant Construction and Bigge Crane & Rigging Co. to install 136 hydraulic jacks under the building, which covers an area bigger than a football field. Another 68 temporary shoring towers support the weight of the building.
The lifting process will take around two weeks and is expected to finish this month.
The jacks must work together to lift the structure 5.5 inches at a time, and the building had to be kept essentially flat as it rose, with no more than a half-inch height difference among segments. The structure also couldn’t move horizontally. That was only possible by connecting the equipment to a computer that would pause work if there was too great of a discrepancy.
“These jacks are all part of the symphony,” said Mike Tzortzis, vice president at Plant Construction. “The computer is the conductor.”
The entire renovation and lifting of the building, which was built in 1941 by the Navy, will cost tens of millions of dollars, with the lift costs totaling about 15% of the budget.
The building is the centerpiece of the $3.5 billion Pier 70 development, another ambitious investment in San Francisco’s southeast waterfront. The plan is approved for up to 2,150 housing units, with 30% affordable, and up to 2 million square feet of office and commercial space, along with 9 acres of new parks and open space. Construction started in 2018 and will last through 2028.
The project is just south of the former Mission Bay railyards that are now a massive UCSF health care complex and the Warriors arena.
In 2022, the steel and concrete Building 12 is expected to open to the public, with a planned makers hall that could include food producers and others offering crafts for sale. The upper two levels will have studios and offices. The project has no tenant commitments yet.
Tim Bacon, senior director of development at Brookfield Properties, said the goal was to change an enclosed building into a public-facing space, while keeping the spirit of manufacturing that fueled shipworkers to work around the clock many decades ago. Massive historic beams are visible inside the building.
“Building 12 has an incredible opportunity, as the heart of this project, to take this creative energy and pump it out,” Bacon said. “When people walk in, it’s really awe-inspiring.”
“We wanted to be transparent and open so people can look and touch and feel,” he said.
Other Pier 70 historic buildings west of the waterfront have been converted into offices for companies including Gusto, Juul and Uber, though the latter two are shrinking their San Francisco operations.
Brookfield and Hearst Corp., owner of The Chronicle, are working on another major San Francisco project called 5M in South of Market. The project, which encompasses the newspaper’s office building, also includes renovated historic buildings.
The lifting of such a massive structure has few precedents in the Bay Area, said John Leventini, Bigge Crane & Riggin Co. project manager.
Other major lifts include Google’s new roof structure in Mountain View, which is part of an office expansion. An older example is the 1986 installation of the Chernobyl Nuclear Power Plant sarcophagus, which contained radioactive fallout from the Russian disaster, and was later replaced by a different structure.
“There’s no job that’s really identical,” Leventini said.