In today's Interesting Engineering we have the following
Elon Musk Wants You To Go Fast
Image by Hyperloop Transport Technologies/jumpstart fund
Really fast.
The South African born entrepreneur has made this clear with literally every business pursuit he’s undertaken. From PayPal to SpaceX, Tesla Motors to Solar City, he’s pursued speed in some way, shape, or form. His latest project is
Hyperloop, a “fifth mode of transportation” meant to supplant road, rail, air, and sea with a more sustainable and efficient alternative. Hyperloop has been dismissed to a significant degree as science fiction, yet it just took a very large step towards becoming a reality. According to Musk,
by the end of 2016, a working test track will be up and running in California.
Musk is a very interesting guy. Armed with twin Bachelor’s degrees from the University of Pennsylvania, (Physics and Economics, the latter from the Wharton School of Business), he set out to make his mark.
At 28 years of age, he sold his interest in his first major business pursuit, Zip2, then followed up with PayPal. By the age of 30, he was well on his way to becoming a billionaire. He’s achieved that goal in spades, yet he’s proven to be much more than another self-serving one-percenter. He’s focused his work on providing better, cheaper technology to the world, and perhaps most importantly, he’s not just a money guy by any stretch of the imagination. He understands this stuff with the eye of an
engineer.
Envisioned by Musk around
2012, Hyperloop is a mass transit system designed to link cities located less than a thousand miles from each other, with high traffic patterns currently served by road and air. The economics behind this logic assumes system efficiency greater than road or air within those parameters, and that project cost on a larger scale would be prohibitive. The system itself is fundamentally based on evacuated tube transportation, which is certainly not a new idea.
In 1812, British mechanical engineer
George Medhurst first proposed pneumatic transportation of people and goods. By the late 19th century, at least one working version, powered by steam, was operational for over a year. In the early 20th century, none other than
Robert Goddard, the father of American rocketry, described a vacuum train system.
And yet with all those precursors, Hyperloop could plausibly trace its roots to science fiction. Mack Reynolds was a popular science fiction author from the 1950s well into the ’70s. His work was largely focused on the socioeconomics of futuristic, utopian societies; he was smart, and a bit of a smartass; he was also one of my favorite authors when I was a kid. In the April
1962 edition of Analog magazine, Reynolds wrote a piece entitled ‘Mercenary’, in which he mentioned ‘vacuum tube transport;’ the concept wasn’t fleshed out in that brief introduction, but apparently the concept had stayed alive.
By the mid 1970s, Robert Salter, an engineer working for the Rand Corporation, and a pioneer in satellite data storage, began to advocate for a mass transit system he called
Vac-Train. Salter’s version was a mag-lev, (derived from Magnetic Levitation), partially evacuated tube train running at hypersonic speed. While as recently as 2010 Chinese researchers have made claims to a viable prototype, the concept remains fundamentally grounded by prohibitive cost. Another variant is being pursued by the team of Dr. James Powell and Dr. Gordon Danby, pioneers in superconducting mag-lev research. Their project, StarTram, is essentially a rail gun intended to allow non-rocket powered space launch.
While there are a handful of operational mag-lev variants around the globe, the technology is not widely used. While offering greater efficiency and lower maintenance cost than traditional rail, mag-lev has distinct challenges; the cost of construction is far higher, low speed operating costs are roughly
15% higher than conventional rail, and a relatively large percentage of operating energy is expended simply to overcome atmospheric drag.
Hyperloop is a bit of a different animal. Its strength lies in hybrid design, taking advantage of proven and viable technology, while solving some of the stickier road blocks with innovative solutions. It’s no accident that the Hyperloop team includes people from both SpaceX and Tesla Motors; if one were an extremely cagey player, as Musk most certainly is, one might have developed and refined those precursorial technologies with something like Hyperloop very much in mind. It may not be as whiz-bang as a vac-train traveling at
6,000 mph, but it’s eminently more practical.
Hyperloop is designed as a passenger only conveyance in these early iterations, with a nod to future abilities to move vehicles. In broadest strokes, it’s made up of bullet-shaped ‘pods’ a little
over 7 feet in diameter that ride within a continuous steel tube, under a one millibar partial vacuum. Pods float on a thin layer of high pressure air, rather than employing mag-lev. This configuration allows for higher speeds than wheels on steel, at a notably lower cost than mag-lev, and the partial vacuum operating environment reduces energy loss to air resistance.
The front of each pod contains an intake fan and compressor; this configuration does several things critical to performance. By sucking in and compressing air at the pod’s nose, air is actively passed through the vehicle, so pressure that would normally build up against the structure is thereby reduced. Secondly, some of that compressed air is diverted to provide the air cushion upon which the pod rides. Third, some of that air is used to pressurize passenger space in the middle of the pod. Batteries are housed aft, and presumedly handle passenger environment as well as augmenting power for air handling. Pod length is an open question, as is virtually the entirety of the project – Musk has insisted that Hyperloop be open source, as a challenge and opportunity for anyone else who wants to pursue it.
Motive power for the pods is produced by linear induction, an AC motor that, instead of producing torque, provides linear force along its length. The design team wants to see system power generated by solar panels, though that level of efficiency is certainly still some ways off.
The steel tubing that forms the guts of the concept is envisioned as being slung on low pylons. The relatively small diameter of the tubing implies the possibility of stringing it along existing freeways like
I-5; in 2013, Mathworks studied a proposed L.A. to San Francisco Hyperloop route and pronounced it generally feasible.
Image by EDIT1306
Computer modeling has indicated pod speeds as high as
760 mph, and inertial forces of around
0.5 g, or roughly two to three times those experienced during takeoff and landing in passenger aircraft. While the speed of sound in dry air sits right around
768 mph, the relatively moist, low pressure air within the Hyperloop system should preclude sonic booms.
All is not wine and roses with a project of this magnitude, of course. There’s no guarantee this thing will work, and there are significant challenges to every facet of it, from cost to manufacturing, and engineering to passenger tolerance. Nonetheless, I find Hyperloop an exciting and promising thing. I was born in 1960, and grew up with the space race and the Apollo program. I know, first hand, everything that we gained from that pursuit. From the smart phone in my pocket to the Prius in my driveway, I’ve reaped the benefits of a lot of blood, sweat and tears, and so have you.
I also recall that Apollo 1 blew up on the pad, killing three austonauts, yet NASA didn’t quit. From that rough start came much, because the engineers and designers and builders didn’t give up. Today, the ISS flies over our heads, a continuance of that legacy. I don’t see Hyperloop any differently; I expect setbacks and challenges, and I’m sure Elon Musk does too. Frankly, I doubt that prospect scares him. On the contrary, I think it spurs him on – And that’s just the kind of guy you want leading this kind of show.
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Elon Musk Wants You To Go Fast appeared first on
Interesting Engineering.
Copyright 2015 UrbanMonique Lummi Bay, WA
