The goal of this project was to run conduit to connect two underground electrical manholes along King Street between 3rd and 4th Streets to provide additional power to San Francisco’s new Central Subway. The project faced major time constraints, including a looming holiday work moratorium scheduled to start the day after Thanksgiving.
Yerba Buena worked flexibly with SFMTA as we encountered multiple obstacles, including a ductbank blockage, which required three major redesigns of the project. Ultimately, we ended up connecting the manholes by digging a 320-foot trench on one side of the light-rail tracks running along King Street and a 60-foot trench on the opposite side. We laid new conduit in those trenches and connected it to some buried “extra” conduit outside the blocked ductbank, which a farsighted SFMTA engineer had installed under the tracks a decade earlier.
After all these changes, we finished construction on Nov. 27, the day before Thanksgiving, winning praise from SFMTA’s project manager for completing the work in record time.
- Project Name: 4th & King Streets Conduit Repair/
- Category: Civil Construction
- Client/Owner: San Francisco Municipal Transportation Agency
- Location: San Francisco, CA
- Dollar Amount: $367,911
- Excavation and trenching
- Extreme time pressures
- Busy, high-traffic location
- Cutting into pipe with high-voltage lines
- Potholing in area full of gas, water, and high-voltage electrical lines