Elon Musk today tweeted that he has verbal approval from unnamed governmental officials to build a Hyperloop tunnel from New York City to Washington, D.C., adding that this would allow for a trip of 29 minutes.
The tunnel would be dug by Musk’s appropriately named firm, The Boring Company, and it would make stops in Philadelphia and Baltimore. That’s pretty much a straight line, and it comes to around 360 kilometers (225 miles), implying an average speed of about 720 kph (450 mph).
Just received verbal govt approval for The Boring Company to build an underground NY-Phil-Balt-DC Hyperloop. NY-DC in 29 mins.— Elon Musk (@elonmusk) July 20, 2017
City center to city center in each case, with up to a dozen or more entry/exit elevators in each city— Elon Musk (@elonmusk) July 20, 2017
Still a lot of work needed to receive formal approval, but am optimistic that will occur rapidly— Elon Musk (@elonmusk) July 20, 2017
It isn’t clear what Musk means by verbal approval or, indeed, by government. A lot of agencies would have to sign off on such a scheme, not least those of the cities themselves. Tunnels come wrapped in red tape—New York City’s Second Avenue Subway line was proposed in 1919 but the first segment was opened only this year.
CNET’s Eric Mack, who broke the story, called the U.S. Department of Transportation for comment and was referred to the White House. There an unnamed spokesman acknowledged Musk’s Tweet, saying “we have had promising conversations to date, are committed to transformative infrastructure projects, and believe our greatest solutions have often come from the ingenuity and drive of the private sector."
Not a very ringing endorsement. Then again, Musk has been in touch with President Trump from the beginning of his administration, even though he and the president have recently had their differences.
As for the underlying technology, everyone seems to agree that it violates no physical laws. Electromagnets would levitate passenger pods, and a linear induction motor—pretty much an electric motor rolled out flat—would accelerate or decelerate it. In between, the pod would coast with almost no losses to friction both because of its levitation and because the tube in which it moves would be kept under a partial vacuum. All this was recently confirmed in full-scale tests run by Hyperloop One, a company founded with Musk’s encouragement but without his direct participation.
Being physically possible is the one solid point in the Hyperloop’s favor. On the other side are a host of picky little arguments: the technology has never been commercialized, it involves maintaining a partial vacuum in an enormous pipe, it’s hard to evacuate people underground in the event of a mishap, and it’s prohibitively expensive to build multiple tubes to provide backup routes.
Oh, and accelerating to several g’s, then decelerating upon arrival, might give many passengers more of a thrill than they can handle. Stopping twice along the way from New York to D.C. would mean either accelerating or decelerating six times in half an hour. In the memorable words of Alon Levy, a Stockholm-based transportation blogger, “It’s not transportation; it’s a barf ride.”