The Hawthorne, California city council has signed off on plans that will let Elon Musk bore his first 2-mile test tunnel for electric vehicles beneath city streets.
Up until now, Musk has had to keep his Boring Company occupied digging under his own SpaceX headquarters in Hawthorne, but Thursday night city officials voted to let Musk dig into city property.
The test tunnel will be 44-feet under Hawthorne's roads and utilities and according to Brett Horton, senior director of facilities and construction for SpaceX, the public won't notice the digging. “They won’t even know we’re there,” he said, even though the giant boring machine will be right below the ground.
Musk has already been tunneling on company property, under the SpaceX parking lot, as part of his quest to bring a Hyperloop mass-transit tunnel network to Los Angeles. The test tunnel expansion route will take it under the northeast corner of Hawthorne Municipal Airport and along 120th street.
The Boring Company still needs to get an encroachment permit which is part of any excavation permitting process before it can start the boring machine to task, and while some citizens have expressed doubts about the project, Horton said the company will test the soil surrounding the tunnel and report back to the city every day. Horton promised that the company's monitoring finds the surface ground moves so much as a half-inch, they will stop digging.
The tunnel-boring machine that will do the bulk of the work was purchased after it was used to dig a sewer line in San Francisco. “Everything happens underground,” Horton said. “We won’t have construction crews walking down the street. We won’t have excavators.”
Earth removed from the tunnel may find itself made into bricks or concrete blocks, instead of being trucked elsewhere. The Boring Company has been experimenting with ways to reduce the cost of tunneling and be environmentally friendly. In a company statement, Boring said, “These bricks can potentially be used as a portion of the tunnel lining itself, which is typically built from concrete. Since concrete production accounts for 4.5% of the world’s greenhouse gas emissions, earth bricks would reduce both environmental impact and tunneling costs.”
The project is expected to take about five months, advancing about 60feet per day. After the test tunnel is finished, the city can ask the Boring Company to fill it back up with concrete slurry or soil.
Musk has said he eventually hopes to extend the Hawthorne tunnel into Los Angeles, ending at Los Angeles International Airport.
Image and video: The Boring Company