4 Reasons Elon Musk’s Hyperloop Could Tank

Don't expect to be riding one by 2020.

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Elon Musk

Rendering of a Hyperloop tube stretching from Los Angeles to San Francisco.

Billionaires — so much pressure to deliver the ineffable, so many people to potentially disappoint. Last night was a little like the buildup to Dean Kamen’s “Ginger,” the press tripping over itself to hand entrepreneur Elon Musk a megaphone, as if waiting for a robed figure to descend from the rumor-clouded mountaintop carrying a phablet with the words “Thou shalt build a pneumatic tube that flings people between distant cities like bank deposit slips” scrolling across the screen.

Elon Musk’s so-called Hyperloop — a slender tube filled with pods that would zip along at hundreds of miles an hour spaced just moments apart — isn’t so far-fetched, steeped as it is in existing technology; indeed, some are saying Musk has invented nothing at all, that he’s merely taken existing tech and shuffled it around. Regardless, it’s hard not to be impressed with some of that shuffling: Fans that suck air from in front of the train to compressors that fire it from the tube bottom to keep the air pressure low? Using the air “cushion” generated by such a system to “levitate” the train a bit like a puck floating on an air hockey table? Solar panels along the tube’s top — including battery packs that store energy to offset cloudy days — that provide “far in excess of the energy needed to operate”?

The idea is that you’d be able to walk (or drive — Musk is proposing being able to transport vehicles, too) into one of these pods every so many minutes, like queuing for the world’s fastest ride at the world’s longest amusement park. As Doug put it last night, “The concept seems like how a roller coaster works: line up, file into an open seat, buckle up and hold on.”

So the question isn’t whether it’s possible — all kinds of crazy-cool-sounding things are possible – it’s whether it’s a good enough idea, or the best in an ocean of grand ones (maybe it is, maybe it isn’t — just putting the question out there). The difference between a guy like Elon Musk and all the other big thinkers pitching society-changing inventions, is that he has the wherewithal to make an idea like the Hyperloop happen.

Or does he? Consider some of the more obvious (and a few less so) obstacles.

Musk claims the Hyperloop would be safer than flying, but has he thought it through?

Nothing’s perfectly safe, of course, so the question’s really whether something like this would be safe enough. Musk has already attempted to deflect worries about natural events like earthquakes, noting that the tube could be built to at least the specifications earthquake-resistant buildings are; that it would be “immune to wind, ice, fog, and rain”; that since the propulsion system is part of the tube itself, it’s inherently speed-limited by the design of each section (you’re essentially removing weather and human control error, he says); and since the pods are completely contained within the tube — to say nothing of the lack of physical rails — train-style derailment is impossible.

But while the Hyperloop would include safety systems, from oxygen masks (in the event of depressurization) to emergency brakes and retractable wheels in each pod, systems like these aren’t impervious to glitches, power outages, battery backup failures, etc., and the margin for error here sounds relatively slim: In a plane, you have the entire sky at your disposal (even then, air-based collisions can and do occur); in the Hyperloop, you’d have up to 28-passenger cars departing every two minutes on average or every 30 seconds during peak-use periods, putting up to 70 or so pods in a tube connecting Los Angeles to San Francisco and more than twice that number in a 1,000-mile version. Given their speeds and departure intervals, they’d be separated by appreciable distances, but what happens if there’s a problem that forces the pods to slow or come to a stop and the brakes fail in even one?

The most serious concern, however, which Musk glosses over in his alpha paper (see section 4.5.6, “Human Related Incidents”), would be terrorism, say someone managed to smuggle a bomb onboard, or fired a rocket at the tube (or one of its bracing pylons) from a distance. Remember, we’re talking about tubes that could cover up to 1,000 mile stretches. Think about our southern border security issues, then imagine if that border also included hundreds or even thousands of potential human targets — locked inside tubing that might vector through huge swathes of remote areas — at any given moment.

Elon Musk now says he might build a prototype, but he’s got a lot going on.

Musk’s initial position was that he didn’t have time to build the Hyperloop, but as All Things D reports, he’s backpedaled a bit by saying, “I think it might help if I created a prototype.”

Elon Musk is CEO and chief designer at SpaceX, a private aerospace company he founded in 2002 with around 3,000 employees and dead serious plans to establish human colonies on Mars. Musk is also CEO, chairman and product architect of Tesla Motors, the electric car company in the news recently for its unexpectedly strong earnings and again earlier this year for Musk’s very public dustup with New York Times‘ critic John Broder. Last but not least, Musk is the chairman of a public energy company called SolarCity. In Musk’s own words, talking to Businessweek about the Hyperloop: “I wish I had not mentioned it. I still have to run SpaceX and Tesla, and it’s fucking hard.”

The point being the guy’s already overcommitted — what are the odds he’ll have the time, energy and resources to bring a project this audacious to fruition?

The Hyperloop may have heat dissipation and wind concerns.

Noticed by USA Today, energy analyst Sam Jaffe, writing on the Navigant Research blog, says Musk’s Hyperloop has at least two potential show-stopping issues the innovator doesn’t address in his paper. According to Jaffe, who specializes in energy storage technologies and applications:

The biggest concern with this plan has to do with temperature. The pod will be compressing air and expelling it downwards and backwards. All that air compression creates an enormous amount of heat, which can damage the pod and its machinery. Musk’s solution is to add to each pod a water tank that will capture that heat and turn it into steam to be collected at the next station. Although the thermodynamic calculations are correct, a small pod with only a few cubic feet of room for a heat exchanger leaves little space for an efficient exchange of heat. That means that the flow of water must be increased, requiring a lot more water on board. There may be an elegant solution for this challenge, but it’s not in Musk’s current paper.

Wind stress is another challenge. Any structure elevated 100 feet off the ground is going to be under a lot of wind pressure, which will act on it in weird and sometimes multiple directions. If that structure is a heavy tube stretching hundreds of miles in either direction, you effectively have a big sail. Will the concrete pylons be powerful enough to resist that pressure?

The annals of invention history are cluttered with bold ideas that went nowhere.

Think Edison’s Diamond Disc or Tesla’s coils. Think Betamax, Nintendo’s Virtual Boy, New Coke, Microsoft’s Clippy, and Segway. Think Ludwig Dürr’s hydrogen blimp and Da Vinci’s gyrocopter. While Musk deserves accolades for putting his idea out to the public, open source-style, the chances of the Hyperloop happening when the actual costs are tallied, timeframes double-checked and potential political red tape measured…well, despite Musk’s claims that you could turn the Los Angeles-to-San Francisco version of this system around inside seven years, I wouldn’t make plans to ring 2020 in riding this thing.