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Hyperloop and the future of ground transport

Elon Musk, founder of SpaceX and co-founder of PayPal, has announced his vision for a new high-speed ground transportation system called “Hyperloop”. The system would connect Los Angeles to San Francisco…

It won’t look that sexy, but the concept is worth the attention. SpaceX

Elon Musk, founder of SpaceX and co-founder of PayPal, has announced his vision for a new high-speed ground transportation system called “Hyperloop”. The system would connect Los Angeles to San Francisco and, compared to the high-speed train link under development, it could provide a more efficient, reliable, low-cost and green(er) alternative.

Beyond the technological aspects and the project’s feasibility, this announcement is crucial to the current and future developments of high-speed land transport systems meant for mass use. While the technologies needed to develop the Hyperloop are not new, it is the first time that a proposed system looks at combining them in a plausible way.

In what is becoming Musk’s style, the Hyperloop tries to solve a known issue with simplicity and style. Designed around customer needs, it claims to provide an alternative choice that is relatively cheap (US$6 billion to build and operate vs US$70 billion for high-speed rail), fast (bringing the commuting time to 30 minutes between the two cities), environmentally friendly (with limited land use, noise and emissions footprint) and, most importantly, safe.

Concept design for seats. Too cramped? SpaceX

The Hyperloop goes one better than previous systems proposed by others (such as the RAND corporation and ET3), by not relying on a tube held in a state of vacuum (pretty much impossible over 350 miles) but instead using a low pressure system that is easier to construct and maintain.

Also, by classing Hyperloop as an “open design concept” and releasing a preliminary design, Musk has ensured that the people who would be most affected by such a system are able to gauge the advantages for themselves. The scientific community can collaborate by scrutinising the technical aspects and offering suggestions and feedback.

Hyperloop vs high-speed rail

High-speed rail links can be an efficient and fast way to travel, and introduction of new lines can affect the growth of the aviation industry on certain sectors or routes. But the overall cost of development, the system’s environmental impact and safety concerns about top-speed limits often make it difficult to justify new developments.

Concept sketch. You can see the air intake on the nose of the capsule. SpaceX

All open air systems face a simple problem: air resistance or drag. If we consider MagLev, which is the fastest unconventional rail system (one that uses electromagnetic forces of attraction or repulsion to levitate and propel an object, like the Transrapid-09 or the Shanghai line), even it faces a lot of drag at high speeds. The drag forces quadruple as the velocity of the object doubles, to overcome that drag force it needs eight times the power to increase its speed. Thus drag limits the top speed for ground-based open air systems.

Solar panels will line the tube providing power to the induction motors. SpaceX

Hyperloop has been designed to overcome this. By operating in a low-pressure environment that allows for lower air density the system limits the amount of drag it would face to begin with. This coupled with the compressor leading face allows the Hyperloop to channel the air in front of the capsule and funnel it to the back to generate extra thrust.

Riding on an air cushion, with minimal drag, the Hyperloop would in theory also allow for variable top-speeds depending on the capsule configuration. Future interstate developments could see it compete with road and rail in the transport market.

Is it worth it?

For its price, the Hyperloop is definitely worth exploring. Its simplicity in design and Elon Musk’s reputation of finding innovative and (relatively) inexpensive solutions to big problems are certainly appealing. The idea offers an alternative to current day systems that are limited either by design or fundamental physics. It also illustrates how one can use current off-the-shelf technology to design a new system that can be safe, reliable, commercially affordable and a cheaper alternative for the end user.

Drawing on the expertise of his teams at SpaceX and Tesla Motors, Musk has taken on another grand challenge. Having provided an alternative to space, road and now high-speed rail transport, who knows, in years to come we might even see Musk’s vision for supersonic air travel.

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3 Comments sorted by

  1. John McPherson

    public transport advocate

    Elon Musk has to be taken seriously - a bit. But some of his sweeping claims about conventional high speed rail are over the top. Safety for one. Not one death in 50 years of Shinkansen operation in Japan. Sure HSR building costs are high; but magnetic levitation is more expensive by a factor of 10. Developing his concept would require many extra protection systems, for instance, all adding to complexity, weight and cost and bringing it closer to more conventional land based transport options…

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    1. Tan Sharma

      Associate of Informatics at University of Sussex

      In reply to John McPherson

      Hi John,
      I agree that MagLev development is currently rather expensive, and that's one of the main reasons that there are limited commercial operations. However, unlike other proposals (ET3 for one) Musk's plan is not to use MagLev technology throughout the tube. The levitation and propulsion systems will be deployed at intervals to help maintain and boost speed (as per the specifications in their paper).

      Having said that, there is a reason Musk isn't planning on acting on this soon. It is an interesting concept, and i feel it shall remain that way for the next few years until one can prove the viability and commercial feasibility of such a project.

    2. Joe Hope

      logged in via Facebook

      In reply to John McPherson

      Essentially every one of these questions is addressed in the hyperloop alpha technical document.

      - The capsules have significant self power (although much of the drive comes from a series of external linear induction motors.

      - The control system to keep the capsules apart is trivial. They are separated by tens of kilometres in the highest density traffic.

      - The capsules need very little ongoing drive, so it would take essentially a disaster to stop them. (Loss of power to the system…

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