Tunnel technology is older than rockets, and boring speeds are pretty much what they were 50 years ago. As with space launches, tunnels are often funded through cost-plus government contracts, in which the contractor assumes no risk for cost overruns, which tend to be enormous as a result. Famously, Boston’s Big Dig, which moved a section of Interstate 93 underground, was delayed by roughly eight years and cost $12 billion more than originally planned, but all tunnels tend to be wildly expensive. In L.A., plans to extend the subway’s Purple Line by 2.6 miles will cost more than $2.4 billion and take almost 10 years. “It’s basically a billion dollars a mile,” Musk says. “That’s crazy.”
Musk wouldn’t comment on Trump, but a person close to him says that while the Boring Company would be open to building tunnels as part of Trump’s infrastructure plan, it intends to move forward regardless of what happens in Washington. Musk says he hopes to build a much faster tunneling machine and use it to dig thousands of miles, eventually creating a vast underground network that includes as many as 30 levels of tunnels for cars and high-speed trains such as the Hyperloop.
Objections spring to mind. Such as: Wouldn’t having hundreds of feet of hollow tunnels destabilize the ground? Nope, Musk says, the mining industry does it all the time. “The earth is big, and we are small,” he says. “We are so f—ing small you cannot believe it.” Not only are these megatunnels possible, he argues, they’re the only way we can rid ourselves of the scourge of traffic.
“We have skyscrapers with all these levels, and we have a flat, two-dimensional road system,” he says. “When everyone decides to go into these structures and then exits them at the same time, you’re going to get jammed.” Tunnels, on the other hand, would represent a 3D transportation network.
Musk chose the SpaceX parking lot as the site of his first dig, mostly because it was convenient and he could legally do so without city permits. The plan is to expand the current hole into a ramp designed for a large tunnel boring machine and then start digging horizontally once the machine is 50 feet or so below ground, which would make it low enough to clear gas and sewer lines and to be undetectable at the surface. The company, such as it is, is working on securing permits and hopes to have them by the time the tunnel hits the property line. At the moment, Musk won’t say exactly where this “demo tunnel,” as he calls it, will lead—only that it will accommodate cars and be the very beginning of a vast underground transportation network.
As crazy as tunneling sounds, Musk points out that it’s arguably less crazy than Silicon Valley’s go-to traffic solution: flying cars. Google’s Larry Page has funded two personal-aircraft startups, Zee.Aero and Kitty Hawk, and companies such as Uber and Airbus have skunk works. But Musk thinks flying cars are a dumb idea, at least for city travel. “Obviously, I like flying things,” he says. “But it’s difficult to imagine the flying car becoming a scalable solution.” As long as the laws of physics hold, he explains, any flying car will need to generate a lot of downward force to stop it from falling out of the sky, which means wind and noise for those on the ground, not to mention debris from midair fender-benders. “If somebody doesn’t maintain their flying car, it could drop a hubcap and guillotine you,” he says. “Your anxiety level will not decrease as a result of things that weigh a lot buzzing around your head.”
Nextbigfuture NOTES – Elon objection to uncontrolled flying cars would be the same for very large numbers of sizable drones. Flying drones pr flying cars would need to have corridors where they could travel and where the risk of anything falling or falling off would be mitigated.
Musk has brought me to the site of a municipal project to kick the cutting wheels, so to speak, on a used boring machine he’s considering. The machine is 26 feet in diameter, about 400 feet long, weighs 1,200 tons, and is nicknamed Nannie. It’s been used by Washington’s water utility to dig a tunnel to prevent sewage from overflowing into the Anacostia River. New machines normally cost at least $15 million, but a decade of frantic subway construction in China has created a glut, and lightly used models can be had for 90 percent off sticker.
He plans to use a machine like this to test improvements in tunneling technology. He thinks that with more power, better materials, and a design that allows it to continue digging while installing the tunnel walls—a feat that’s impossible today—the Boring Company will be able to drastically reduce the price of digging. “To make it a little better should be easy,” he says. “To make it five times better is not crazy hard. To make it 10 times better is hard, but nobody will need to win a Nobel Prize. We don’t have to change the standard model of physics.”
As we walk through the machine, Musk and Davis pepper the tunnel’s project manager, Shane Yanagisawa, with questions. They ask about grouting materials and staffing, but mostly about speed. Yanagisawa says the limiting factor is muck. Nannie’s conveyor belts can carry only so much dirt at a time. The fastest he thinks the machine can possibly run is 75 millimeters per minute. In a typical week, it moves through 300 feet of clay.
Musk nods. “We’re trying to dramatically increase the tunneling speed,” he says. “We want to know what it would take to get to a mile a week? Could it be possible?”