For short distances, Musk imagines cars taking an elevator underground, then zipping along on “electric skates” riding on rails at up to 125 mph. (It is worth noting that a civil engineer suggested to my colleague Alex Davies that Musk's idea belongs "in the bullshit category.") For longer trips—say New York to Washington, DC—the Boring Company expects its tunnels to house a hyperloop. For the three or four of you who haven't heard, hyperloop is Musk's idea for whisking people between cities in levitating tubes shooting from one place to another at about 700 mph in near-vacuum.

Say hello to Godot, the Boring Company's tunnel boring machine. The Boring Company

The key to making these things work is tunneling. And the key to making tunneling work, Musk says, is improving the speed, efficiency, and cost of digging big ol' holes. Of course he's very optimistic about his prospects for this. "It's quite difficult to dig tunnels normally," he said in a February TED Talk. "I think we need to have at least a tenfold improvement in the cost per mile of tunneling." Eager to make that happen, Musk bought a used boring machine in May and rechristened it “Godot”. But he isn't waiting.

OK, So What’s This Tunnel?

The Boring Company wants to build a 2-mile test tunnel 20 to 24 feet underground. The plan calls for making it about 12 feet wide, or about the width of a standard highway lane. No need to make it any wider, SpaceX senior director of construction Brett Horton told the city council, because those car-carrying skates don't need a shoulder.

For all his talk about revolutionizing everything but revolutions, Musk isn't doing anything radical here. The Boring Company will use thoroughly conventional tunneling. “This is a proven machine that has already done a tunnel in Sunnyvale,” California, Horton said. “Same segment design, same tunnel-boring machine design. We’re not reinventing the wheel on that.” Digging this tunnel, he said, would let the Boring Company learn about the capabilities of the machine and find ways of making improvements.

Horton also told the council members that the tunneling process, which should take just eight months, would prove the company can build “safely, reliably, and for significant cost savings to traditional tunneling projects.”

How Do They Build It?

Horton took pains to explain to Hawthorne officials that construction would not disrupt anyone. Most of the work is slated for SpaceX’s campus (where, for example, the dirt gets dumped). Godot will be working so deeply underground that no one will feel it, Horton says. (Yes, that's possible if the ground is soft enough, construction experts say.) And the company will of course carefully monitor the ground level to make sure the surface isn't shifting. No one wants any sudden sinkholes.

There's a lot of stuff buried underground, of course, and Horton said the Boring Company has reached out to 19 utilities that might have lines in the area. The untold miles of gas, electric, fiber-optic, sewer, and water lines crisscrossing under the nation's cities present a knotty problem for tunnels and tunneling, especially since they can shift when the ground starts moving. The implications of hitting any of these could be really, truly bad—imagine a city's drinking water suddenly polluted with raw sewage, or a vast swath of the population left in the dark. And you think a sinkhole is bad PR.

Horton spent a fair amount of time outlining the myriad ways the Boring Company has complied with safety regs. “We want this tunnel to be ridiculously safe,” he said. “I want to be able to take my little 5-year-old and 3-year-old in the tunnel to show it to them.” CalOSHA says it issued the permits required to complete the tunnel already built on SpaceX property, but it won't start the process for the expansion until the city approves it.