Brunel had his ships. Trump had his walls. And now Musk wants to make... tunnels, tunnels under cities to reduce traffic congestion and make the world a better, cleaner, less rage-filled place.
Over the weekend, probably while sitting in traffic behind the wheel of an autonomous Tesla, Musk tweeted: "Traffic is driving me nuts. Am going to build a tunnel boring machine and just start digging." An hour later, probably while still sitting in traffic, giving him plenty of time to think of a witty pun, he declared: "It shall be called 'The Boring Company.' Boring, it's what we do."
And finally, an hour after that, just in case any of us were foolish enough to think the billionaire multi-CEO was joking, Musk said, "I am actually going to do this." He also changed his Twitter bio to include "Tunnels."
So, unless Musk was suffering from a prolonged bout of entrepreneurial road rage, we now know roughly how long it takes a pedigree industrialist to pick a new disruptible domain: two hours, give or take.
Tunnels are indeed a pretty good solution for traffic congestion, though they take a long time to build, and the construction usually causes a huge amount of disruption above ground—especially if those tunnels are being built in a metropolitan area, which is where you'll find most of the world's congestion.
Depending on the setting, it can be very difficult and expensive to build tunnels as well. Cut-and-cover—where you dig up an existing road, build a tunnel, and put the road back—is the only "cheap" tunnel building method, but it's so incredibly disruptive that most tunnels nowadays are built at deeper depths by automated tunnel boring machines (TBMs). Cost-wise, you're looking at about £1 billion per mile for TBMs: London's Crossrail, with 13 miles of new tunnel, will cost around £15 billion; Manhattan's second avenue subway line, with 8.5 miles of new tunnel, will cost about $17 billion. The costs are much lower if you just want to bore through a mountain—the just-completed 35-mile Gotthard Base Tunnel through the Alps in Switzerland cost a mere £10 billion (and took 17 years to build!)—but I doubt Musk has those kinds of tunnels in mind.
(Score: 1) by Francis on Wednesday December 21 2016, @12:33AM
A large part of it comes from the soil monitoring that goes on. You have to constantly measure the soil going out with the progress of the machine so that sinkholes don't develop. There's also huge amounts of pressure to begin with and over the course of the route, you can't deviate by more than a few centimeters. especially if the machine is planning on meeting up with another machine in the middle.
Also, tunneling through granite is rather unusual, if you've really got granite all the way, then tunnels are a poor design decision. If you're going through hard rock, then there's not much point in using a machine rather than having people do it.
(Score: 2) by VLM on Wednesday December 21 2016, @01:22PM
tunneling through granite is rather unusual
Its interesting to think about how a place like NYC got built because its a nice place for 1700s era sailboats to trade, although annoying to tunnel thru. The city site was kinda fixed before they decided to start digging tunnels.
Likewise it might be an interesting hard sci fi plot-line to figure out a reason to site a city where its actually a good tunneling area, and then figure out the logical (if any) conclusions.
(Score: 1) by Francis on Wednesday December 21 2016, @07:09PM
San Francisco and Seattle are a couple of other examples of cities being located in dumb places. Locating cities on top of so many large hills doesn't seem very efficient for moving goods and services about the city. Even worse prior to the invention of the automobile.
If you're hand digging tunnels, or really using explosives, hard rock is preferable as the tunnel isn't going to cave in on your. However, the softer soils are better with boring machines because they'll build the structural support behind them as they go.
And yes, that would be kind of interesting, but it would probably come down to some sort of dystopian nightmare, in which case, the authorities aren't likely to allow the city to be built there. Perhaps a moon colony would make the most sense as there's no protection against the sun's rays there.