10 things we learned about tunnels and Tesla from Elon Musk's TED interview

Asa Mathat/Recode

Elon Musk is the head of a spaceflight company, an electric car manufacturer / solar energy effort, and a brain-computer interface project. Recently, though, he added a tunnel boring company to that already crowded plate. This past weekend he spoke about The Boring Company, as he’s calling it, for the first time in public with Chris Anderson, the curator for TED Talks.

It wasn’t a hard-hitting interview — while Anderson got Musk to share some details about the tunneling project, he also teed up many of the billionaire CEO’s favorite talking points, and his followups were often “whoa” or “wow.” You can watch the full video above, but here are our 10 biggest takeaways from the conversation.

Musk wants the tunnels to span the country on a deep level

Musk said that there’s “no real limit” to the depth of his proposed tunnels. “The deepest mines are much deeper than the tallest buildings are tall, so you can alleviate any arbitrary level of open congestion with a 3D tunnel network.” This, Musk said, is how to get around the most popular rebuttal so far: that underground tunnels will simply spread the congestion to a new place without completely solving the problem of traffic. Musk thinks it will be possible to create “any arbitrary number of tunnels, any number of levels” in order to reduce congestion on the surface.

There needs to be a massive cost reduction before a tunnel network gets built

Anderson mentioned that this project sounds expensive, and Musk agreed. “We need to have at least a 10-fold improvement in the cost per mile of tunneling,” Musk said. He thinks there are two things that will allow The Boring Company to achieve that kind of cost reduction.

One is to cut the typical diameter of a tunnel “by a factor of two or more” to 12 feet. “A single-lane tunnel would have to be 26 or 28 feet in diameter to allow for emergency vehicles and ventilation for combustion engine cars,” Musk said.

A CGI rendering of the The Boring Company’s concept, where cars would avoid traffic by being pulled underground on “electric skates.”

“But if you shrink that diameter to what we’re attempting, which is 12 feet, which is plenty to get an electric skate [this is what Musk is calling the contraptions that will grab the cars from the surface and move them through the tunnels] through, you drop the diameter by a factor of two and the cross-sectional area by a factor of four. And the tunneling cost scales with the cross sectional area, so that’s roughly a half order of magnitude right there.”

Next, Musk said that he wants to make his boring machines carve out tunnels and reinforce the walls being created at the same time. (Those are currently separate steps.) Musk thinks this could double the efficiency of the process which, combined with smaller tunnels, gets him to a place where he can reduce the cost by a factor of eight.

Musk then amended his short list by adding one more goal. Current tunneling machines don’t operate near their thermal or power limits, and he believes he can beat that. “If you can jack up the power to the machine substantially, I think you can get at least a factor of two, maybe a factor of four or five improvement on top of that,” he said.

The goal for The Boring Company is to beat Gary the Snail from SpongeBob SquarePants

Musk said current tunnel technology literally doesn’t even operate at a snail’s pace. So he’s put a target on the back of the most well-known snail in pop culture: Gary the Snail from SpongeBob SquarePants. “Currently he’s capable of going 14 times faster than a tunnel boring machine,” Musk said. “We want to beat Gary. He’s not a patient little fellow. That will be victory. Victory is beating the snail.”

Hyperloop technology could be used in underground tunnels

Since Musk is now associated with two different kinds of tunnel technologies — one being the underground transportation system, the other being the above-ground hyperloop — Anderson asked him to reconcile the two. Musk said that some hyperloop tech could be used underground since the tunnels are already designed to withstand five or six atmospheres — far more than what’s needed to create the vacuum required for hyperloops to work. Musk believes underground hyperloops would be ideal for certain routes, like Washington, DC to New York City. “There’s no real length limit,” he said.

Musk isn’t leaving Tesla anytime soon

The Boring Company is only taking up “maybe 2 to 3 percent” of Musk’s time. “This is basically interns and people doing it part time,” he said. Anderson then asked if Tesla has done enough for the electric vehicle market to make Musk comfortable with moving on. Musk said he sees himself staying with the company “as far into the future as I can imagine,” because “there are a lot of exciting things that we have coming” including the Model 3 and the Tesla semi truck.

He still has aggressive timelines for Tesla’s self-driving tech

Musk is known for playing fast and loose with the timelines for his grandest ideas. In the interview, he said Tesla is “still on track for being able to go cross country from LA to NY by the end of the year, fully autonomous” with one of its cars, “from a parking lot in California to a parking lot in New York, no controls touched at any point during that journey.”

He also thinks Tesla’s tech is about two years away from allowing a driver to sleep through entire rides. “The real trick of it is not ‘how do you make it work 99.9 percent of the time,’ because if a car crashes say one in a thousand times then you’re probably still not going to be comfortable falling asleep,” Musk said. Instead, he thinks the chance of a crash would have to shrink to one in 100 or 1,000 lifetimes in order for people to be comfortable enough with autonomous technology that they’d be willing to nap in a self-driving car.

Musk says shared autonomous cars are “100 percent what will occur”

A future full of self-driving cars might change how we think about ownership. Musk doesn’t think owning a car will be completely out of the picture, but he believes sharing will play a big role.

“Absolutely this is what will happen: so there will be a shared autonomy fleet where you buy your car, and you can an choose to use that car exclusively, you could choose have it be used only by friends and family, only by other drivers who are rated five stars, you can choose to share it some times but not other times. That’s 100 percent what will occur, it’s just a question of when.”

Musk has driven a prototype of the Tesla semi, and it’s apparently really fun

The Tesla big rig will be unveiled later this year, so it’s no surprise to hear that the company’s got a working version that, apparently, Elon’s already driven. “When I was driving the test prototype for the first truck, it’s really weird, because you’re driving around, and you’re so nimble, and you’re in this giant truck,” Musk said. “I drove it around the parking lot. I was like ‘This is crazy.’ Driving this giant truck and sort of making these mad maneuvers.”

Citing the impressive torque associated with electric motors, Musk said the forthcoming Tesla semi truck can “out-torque” any diesel truck. “If you had a tug of war competition, the Tesla semi will tug the diesel semi uphill.”

Tesla will announce its new Gigafactories this year

Musk thinks that about 100 of his battery-producing Gigafactories might be enough to help shift the world toward completely sustainable energy, and in working toward that goal, he firmed up plans to announce “somewhere between 2 and 4 Gigafactories later this year. Probably 4.” He didn’t say where they’ll be, only that “we need to address a global market.”

Musk played down his connections to Trump

Anderson didn’t push Musk hard on his association with Donald Trump, but he did (kind of) ask Musk to address the criticisms of that relationship. Here’s Musk’s full answer:

First of all I’m just on two advisory councils where the format consists of going around the room and asking people’s opinion on things. So there’s like a meeting every month or two. You know, that’s the sum total of my contribution. But I think to the degree that there are people in the room who are arguing in favor of doing something about climate change or you know other certain social issues — you know, I mean, I’ve used the meetings I’ve had thus far to argue in favor of immigration and in favor of climate change. And if I hadn’t done that, there wouldn’t — that wasn’t on the agenda before. So maybe nothing will happen, but at least the words were said.


That’s a lot of batteries….

And if I hadn’t done that, there wouldn’t — that wasn’t on the agenda before. So maybe nothing will happen, but at least the words were said.

Definitely shows that the guy is a practical thinker. There are plenty of people that would refuse to participate purely on the grounds of taking a principled stand. He seems to care more about results than principles.

Or his biggest principle is getting results.

Next, Musk said that he wants to make his boring machines carve out tunnels and reinforce the walls being created at the same time. (Those are currently separate steps.)

Tunnel boring machines already do that though, so how is that new?

He said that’s what’s needed to cut costs, not that he invented those machines.

That’s exactly what I thought. I was under the impression that most TBMs already do this. Maybe he means actual finished tunnels?

How I understood it was that current machines do this in separate steps – that is boring out part of the tunnel then creating the wall. Whereas Musk envisions a TBM that can do this continuously.

That’s a great video! As far as what Elon is talking about, I imagine he plans to add some level of integration or streamline the existing process

Is it just me or is Elon Musk the new Ford?

While it’s easy to dismiss Musk’s timelines as overly aggressive, or some of his ideas as "crazy", or impractical, I really appreciate that he’s actually doing, or trying to do, things. I remember 15-20 years ago it wasn’t uncommon to read about some newfangled technologies and ideas in Wired, or PopScience or some such, they were all so exciting with diagrams and illustrations and artist’s renders… and that’s that – 90% of them, you read about them, and then you never heard of them again. With Musk though, if he’s got an idea he goes ahead and tries to actually make it happen. He went from tweeting about The Boring company to actually building a boring machine in what, like 2 or 3 months. That’s freaking awesome!

Anyway, so far, while he slipped many a time on his timeliness, he has delivered on everything he promised. I don’t know if that streak will continue, but I’m excited to watch what he will do next, no doubt about it.

He didn’t actually build a machine, they’ve just been working with a second-hand machine they purchased. I imagine they plan to build something eventually though.

The whole tunnel thing is stupid and he completely does not understand the engineering complexity of tunnelling underground. It’s not simply about cost per meter. They are building tunnels under New York right now, biggest ever, and it takes decades to plan and achieve. It’s not a question of better machines or more gumption, it just takes fucking time, engineering, planning, approval and money. And they’ve had the kind of tunnel boring machines for decades now, it’s what built the Chunnel.

Now try to achieve what Musk wants under New York. Hundred of miles of interconnecting tunnels to allow cars to move around quickly in what, 10 years, 20, 50 years? And where? 300 feet below the city under all the existing infrastructure? And real life ain’t like Minecraft, sometimes you just can’t build a tunnel, period.

What does this achieve? A subterranean Fraggle Rock network for 0.1%ers to use?

Finally, ultimately what makes this fix traffic. The problem with traffic is too many people trying to access too limited a resource, whether it’s roads or a tunnel, and the tunnel network is even more limited a resource so you have a lot of people fighting to use a limited resource still.

Self driving cars, SpaceX, even hyperloop and going to a Mars are all achievable, but building hundreds of miles of tunnels under a city so billionaires don’t get stuck in traffic, I am calling that out as just plain stupid. I don’t care how rich the guy proposing this is, an idea isn’t smart just because a rich white man goes on Ted talk to announce it.

Few people belived that landing & reusing rockets can be done either, much less by a startup. Yet SpaceX went ahead and did it.

In addition you talk as if Elon Musk is just some random "rich white man". The guy is from South Africa, came to North America and started building one successful company after another. At this point it seems like a pretty bad idea to bet against him.

I’m sorry to say you’re pretty typical for why most people don’t get these things to work.

Elon has consistently said "fuck that" to anything people tells him he cannot do. Then he goes ahead and does it. A lot of things are achievable if you don’t accept no for an answer.

He has BMW, GM, VW and a host of others introducing long-range electric vehicles in the next couple of years. Ask them about that 5 years ago, and they’d laugh at you. This is ALL on Elon Musk. It wouldn’t be happening if it wasn’t for him and his steadfastness.

It’s not like he’s replacing roads with tunnels, the roads will still be there as tunnels are built lol. Besides, high speeds (125mph) also reduce the amount of people using tunnels because they’re down there for a much shorter time and then that capacity becomes available much sooner. And they’re planning for tunnels to take passengers as well, almost like staged minibusses. So that’s even less traffic per passenger because 12 people cash occupy the same car.

My favourite thing in the world is when someone says something cannot be done, and someone else comes along and proves them wrong.

Give it time…

I concur with your points on a purely pragmatic level. However, even if this doesn’t pan out it’s still a route being explored that could lead to something completely different and unintended that is good and advances human society forward.

Do you have any idea why building tunnels in NYC takes so long and costs so much? It’s not the difficulty or the planning. Similar projects are achieved in for example London, both cheaper and faster. It’s the cronyism and the corruption. The same reasons that for example the MTA maintains a machine shop to manufacture parts for systems that are probably 80 years old! Why Penn station is a laughing stock and has had 2 derailments in the past month or so. It’s not that they can’t make it better… there’s no incentive for them to do it, unless things are literally falling apart. This city is infamous for that, and is a horrible example. Notice how long it took to build the new world trade center compared to the old one. Do you think they had better technology in the 60s and 70s? Or less palms to grease?

You can’t point to a city run project and say it would take someone like Musk just as long to do it.

Earthquake proof?

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