Hyperloop Transportation Technologies highlighting passive magnetic levitation

Hyperloop Transportation Technologies highlighting passive magnetic levitation

Hyperloop Transportation Technologies on Monday announced their technology approach to bring a transport levitation system to fruition. They are using something called passive magnetic levitation.

They have been working with the Lawrence Livermore National Lab on this and HTT has now exclusively licensed the system from the Livermore lab for the Hyperloop application. Could this be a transport levitation system that will cut costs, save time and preserve energy?

Those are admirable goals and a confident HTT provided information about their efforts in a video posted on May 8. (Ars Technica provided some background information on their work, saying HTT's magnet-and-coil setup which they used had its roots at Lawrence Livermore Lab in the 1990s. The system was invented by the late Dr. Richard F. Post.)

Some of the points raised in the video:

Maglev trains need expensive infrastructure. [Maglev refers to a transport mode using magnetic levitation without touching the ground with electrically charged magnets lifting and moving the train above the tracks.] Their system involves a "Halbach array," specially arranged rows of . (The MAGCRAFT information blog defines a Halbach array as "a specific arrangement of a series of permanent magnets. The array has a spatially rotating pattern of magnetism which cancels the field on one side, but boosts it on the other. The main advantages of Halbach arrays are that they can produce strong magnetic fields on one side whilst creating a very small stray field on the opposite side.")

Megan Geuss, staff editor at Ars Technica, said in their approach, magnets are placed on the underside of the passenger train in the Halbach arrangement, focusing the magnetic field of a set of magnets on one side of the array while canceling out the field on the other side. "Those magnetic fields under the train cause it to levitate as it passes over non-powered electromagnetic coils on the rail beneath the train at even low speeds created by an electric motor."

Philip Ross in IEEE Spectrum also shed light on how this all works: "The passive levitation system, called Inductrack, was developed in the 1990s at Lawrence Livermore National Labs, in California. It works by lining the bottom of the pod with permanent magnets, placed in a so-called Halbach array so as to induce a repelling field when they pass over shorted, that is, non-powered, electromagnetic coils on the railbed. Because the maglev effect is passive, any power cutoff would both slow the pod and cause it to settle down on the track."

Dirk Ahlborn, the CEO and founder of HTT, told IEEE Spectrum that this passive levitation method saves energy and trouble as "this allows us to achieve levitation without having power stations all along the track."

A passive levitation system will eliminate the need for power stations along the Hyperloop track, and it will keep construction costs low, added Bibop Gresta, COO of Hyperloop Transportation Technologies. Gresta said yet another plus in their tech was safety.

"From a safety aspect, the system has huge advantages, levitation occurs purely through movement, therefore if any type of power failure occurs, Hyperloop pods would continue to levitate and only after reaching minimal speeds touch the ground."

A variety of organizations are currently racing to produce a working Hyperloop, noted Ars Technica.


Explore further

Hyperloop super-fast rail to hit milestone

More information: hyperlooptransp.com/

www.prnewswire.com/news-releas … ystem-300264946.html

© 2016 Tech Xplore

Citation: Hyperloop Transportation Technologies highlighting passive magnetic levitation (2016, May 11) retrieved 23 September 2019 from https://techxplore.com/news/2016-05-hyperloop-technologies-highlighting-passive-magnetic.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
57 shares

Feedback to editors

User comments

May 11, 2016
The passive maglev system is also inconvenient because the levitation force is proportional to the speed, and you can't control it in any fashion, which means the load affects how fast you can go before the train lifts off the track, and because the coils act as a magnetic brake due to the way the opposing field is induced in them by the movement of the carriage.

The lift-to-drag ratio of the indutrack at 300 MPH is said to be about 200:1 while the load-to-drag ratio of steel railroad tracks is about 1000:1.

That means the indutrack train uses five times more power to move the same load. At higher speeds it approches the efficiency of ordinary tracks due to the increasing impedance of the coils, but it never quite reaches the plain efficiency of simply rolling a steel wheel on a steel track - and it requires many times the metal to make the track coils.

May 11, 2016
Also consider that the magnetic levitation works over a very short range of couple inches. In terms of suspending the pod, it works like a spring that gets stiffer and stiffer with speed, which means it transmits vibration from the track to the pod the more the faster you're going.

Now, the pod is travelling at 760 mph which is about 340 m/s through a tube which is suspended every 30-50 meters or so by a pylon. Suppose thermal expansion, wind loads, the dynamic track load itself, construction tolerances etc. put every pylon an inch off in a random direction so the tube and track isn't precisely straight - that means you're rattling the pod and everyone inside like a jackhammer at a frequency around 10 Hz like a car going over a washboard road.

Gonna need some good shock absorbers for that one. It also puts some wild forces on the track itself.

May 11, 2016
@cupoli771 Not only is that comment completely unrelated to the article, it is frankly disgusting. I can't imagine what sort of lowlife you must be to prey on people in times of weakness at the hands of such a serious disease. You should be ashamed of yourself, trying to scam people into false hope with your mumbo jumbo. If you get HIV I hope you contact that doctor and the treatment fails for you also.

May 11, 2016
So the lev is powered by the movement of the train. What's the train powered by? batteries? And what propulsion is it using? Sounds like an electric motor but if it is levitated what does it push against?

May 11, 2016
"What's the train powered by? batteries?"


Low pressure air pushing it along the tube. The whole point of the hyperloop is a pneumatic shuttle that gets injected into a stream of very fast moving air going around in a loop.

May 11, 2016
The biggest problem with Hyperloop isn't the technical issues, tube, etc though they'll be a problem.

The problem is that it'll carry groups of people. The maths of group transport technologies - all of them share the same characteristics - is such that using the service will be slow, inconvenient, expensive and will be capable of carrying only a tiny percentage of journeys.

When you travel with a group of other people, the vehicle must stop at all stations to allow passengers on and off. This requires deceleration, a period spent stopped before it can accelerate to speed again.

If there are many such stations, then the average speed is dominated by the time spent stationary, but it's relatively easy to get to and from these stations.

If there are very few stations, then the average speed of the vehicle will be high, but you must then travel long distances to reach a station and it's utility is limited to those who live nearby.

The problem is maths & physics.

May 12, 2016
The poster Cupoli771 appears to be a scammer maybe protected by the site, as I am unable to 'report' him. When I do, the 'report' button on the popup refuses to work. So all you readers and posters be warned about this obvious crook Cupoli771 who preys on the sick and the desperate with false offers of a 'cure for AIDS'.

May 12, 2016
"The answer is to have a detachable car at the end of the train."

?

The answer is to transport individuals, not groups; see example of bicycles, motorcycles, automobiles. The vehicle should support *no more* than a family plus luggage. 4-5 people.

Stations can then be "off line" so *every* journey is non stop at peak speed to the destination. No energy or time wasted accelerating and decelerating in between.

Additional benefits of packetised transport:

The individual vehicle is then also small, light, cheap and therefore mass producible. The infrastructure can then also be *much* smaller, lighter and cheaper because the vehicle is in the hundreds of kilograms range not the hundreds of tonnes range.

There is no schedule. Passengers don't have to wait at a station for a vehicle to arrive, the vehicle already waits at a station for the passenger and departs immediately.

Because there is no schedule, vehicles also don't have to run empty.


May 12, 2016
"The vehicle should support *no more* than a family plus luggage. 4-5 people."


Those have been tried and they're never economical. The problem of running the empty cars around and distributing them back according to demand causes extra running costs and delays over everyone just driving their own car, and offer no practical advantage.

And that's not the point of the Hyperloop. It's a long-distance cross-country point-to-point high speed transport service that combines the speed of an airplane to the efficiency and low cost of a train - or at least attempts to. It's never meant to stop anywhere but at the ends.


May 12, 2016
"Because there is no schedule, vehicles also don't have to run empty."


You wish. The problem is that large amounts of people tend to go the same way at similiar times, so the vehicles stack up at one end of the network and there's no more available until someone goes back the other way, or you send an empty car on its own.

Even if there are an equal number of pods as people - which would be wasteful and expensive - there's still a great chance that there's no pods at the particular station you are at because someone just took off with the last one, and you have to wait for someone else to arrive - which could be minutes or hours.

May 17, 2016
"Those have been tried and they're never economical. The problem of running the empty cars around and distributing them back according to demand causes extra running costs and delays"

Not the case. They have never been tried and found to be un economical. There has been several research systems over the years and they've failed for several reasons, some technical, some political and certainly not because vehicles have to "dead head". The technical problems have largely been solved. How to implement such a system successfully is now well understood. Only the political issues remain.

*All* public transport systems have to "dead head" their vehicles. Buses, trains, trams, even taxis and Hyperloop. *All* of them have to run empty in the opposite direction to prevailing commute directions to manage capacity.

"and offer no practical advantage"

A typical "pod" can handle tens of journeys per day and travels non stop, that's a practical and economic advantage over a car.

May 17, 2016
"The problem is that large amounts of people tend to go the same way at similiar times, so the vehicles stack up at one end of the network"

No, they don't. On delivery to destination, the vehicles are immediately re-assigned. It's fairly trivial to maintain a depot of vehicles in excess of the number of station bays such that the time spent waiting is minimized or indeed, eliminated for the overwhelming majority of journeys.

There is one similar *commercial* system in operation today, at Heathrow airport. The system installed has 20 vehicles, but handles ~1000 journeys per day (it's a small system). A ratio of 50:1 in terms of vehicles numbers to journeys. 80% of journeys have zero wait time, of those where there is a wait, the average time is 12 seconds.

May 17, 2016
"And that's not the point of the Hyperloop. It's a long-distance cross-country point-to-point high speed transport service that combines the speed of an airplane to the efficiency and low cost of a train - or at least attempts to. It's never meant to stop anywhere but at the ends."

Then, it's as useless as any other inter-city rail service. People will have to travel excessive distances in order to reach the Hyperloop stations. This means it will have a small catchment area of people for whom it could be useful.

=> Minuscule capacity and completely insignificant with respect to effects on air transport usage, automobile usage etc.

And with costs which will be similar or likely, far larger than rail on a per mile basis (nobody believes the current cost projections). It's an expensive but insignificant project.

=> White elephant. Ego stroking (and pork, because it will require public subsidies).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more