In October 2015, Marty McFly, in an attempt to outrun a gang of young cyborgian thugs led by the grandson of Biff Tanner, hops onto a hoverboard for the first time ever. A wild chase ensues down city streets, McFly towed along by a passing pickup truck as he is carried aloft. He loses power when he errantly steers the hoverboard over a small pond, but some quick thinking allows him to ultimately avoid the pummeling that was headed his way.
Of course, when Back to the Future II was first released in 1989, the idea of a floating skateboard-style craft was very much a distant fantasy. In 2015, however, we finally have the world’s first hoverboard and it is released just a few short months before the world’s calendar aligns with the time setting of that movie.
Lexus, a brand of automobiles developed by Japanese car manufacturer Toyota Motor Corp. (NYSE:TM), announced in recent weeks the development of a functional levitating hoverboard. Toyota does not plan to manufacture the hoverboard and sell it commercially but the prototype it has developed is capable of carrying a human operator who navigates the board in a way similar to a skateboard. The day it was released, Toyota’s Twitter account was averaging about 1,000 tweets per hour thanks to shares of videos like the one below.
There’s one very important limitation to note when talking about the Lexus hoverboard: it can only be operated across a track which has a metal layer running across beneath the surface. On most roads, skate parks and handrails, this product would drop like a brick. It’s held aloft by magnetic forces strong enough to keep the board four inches in the air. Depending on a rider’s weight, the board hovers between one and two inches off of the ground. The magnets gain enough force to do this with the help of superconductors that are cooled to about -321°F with the help of liquid nitrogen, which creates a vapor trail of exhaust coming from the hoverboard that makes for an interesting added effect.
The superconducting material used to power the magnetic features of the hoverboard is immersed in the liquid nitrogen and held within one of two reservoirs on the board known as cryostats. Putting a magnet into a cryogenic state at these temperatures allows it to conduct a much larger electromagnetic force necessary for creating the magnetic field keeping the board afloat. With its low clearance, some riders did experience problems with skidding along the ground during turns, which sometimes caused an abrupt and painful stop. However, unlike the Back to the Future II model (and most likely in homage to that movie), this model was able to clear a long water feature which would have stopped McFly. These boards do work on water, Data. It just needs to be on a special track, is all.
This hoverboard may be the one getting all of the mainstream attention, undoubtedly thanks in no small part to Toyota’s presence with consumers. Last October, the BBC profiled a hoverboard being developed by another company based on similar principles of magnetic levitation. The Hendo Hoverboard creates a magnetic field through the use of four disc-shaped engines positioned along the board. Again, this unit requires a layer of metal lying under the track along which it is traveling in order to work, so neither of these models are practical for taking off wherever you want on a hoverboard. It’s not inconceivable, however, to think of a day in the near future where we could see hoverboarding as an event at the X Games or at one of the many extreme sporting events sponsored by Red Bull.
The hoverboard by itself is really interesting, if slightly impractical, but the concept of magnetic levitation, or maglev, has been with us for more than one hundred years. The 19th century saw some important discoveries in electromagnetics, when scientists realized that a material could be magnetized and not simply have magnetic properties to attract or repel other magnetic material. The earliest concept of a frictionless train propelled forward by magnetic forces was dreamt up in the earliest days of the 20th century by American scientists Emile Bachelet and Robert Goddard, the latter of which is also considered to be an important pioneer of space rocket technology. Patents for high-speed maglev systems go back to 1907, according to reporting from the BBC.
To propel a vehicle weighing many tons along a track, it’s necessary to do a little bit more than simply put two magnets of different polarities opposite each other, one on a train and one on the track. A consistent magnetic repulsive effect, demonstrated by Bachelet, requires the magnets on either side to quickly alternate their polarity, pushing the magnetized train forward and up. Magnets on the track are powered on as the train passes over through a high frequency oscillating current. The track can include components like propulsion coils, levitation and guidance coils as well as a grooved track for wheel support.
Even though the world has known of the maglev concept for some years, it hasn’t truly been able to capitalize it as an important infrastructure technology that could conceivably emit no carbon, save for the carbon created to generate the energy that powers the magnets. The electromagnetic suspension systems created to power these cars forwards are incredibly cost-prohibitive and as of around the year 2000 construction costs for maglev tracks could reach up to $50 million per mile.
The country which has perhaps made maglev train technology work the best is Japan, which is growing increasingly renowned for its bullet trains. At the end of this past April, a team of engineers from a Japanese railroad company broke a high-speed record, topping out at 374 miles per hour, or about one mile every ten seconds. Not every maglev train is a bullet train; the Linimo line, in operation since 2005, is only about 5.5 miles long and operates at a top speed of 62 miles per hour. In fact, many of the bullet trains in Japan don’t levitate at all. The Shinkansen, a high-speed railway network in Japan which reaches more than 1,600 miles in length, uses a propulsion system powered by electricity delivered directly to the trains through the track.
Elsewhere, maglev has proven to be a much more difficult proposition to accomplish and make commercially successful. In 2008, Germany abandoned a high-speed maglev plan when project costs more than doubled the original €1.85 billion budget. Two years earlier, in September 2006, a maglev train crash in Lathen, Germany, killed 23 passengers, the world’s first major maglev train crash. Over in China, design flaws in the transportation infrastructure and high cost are given as a reason why an 18-mile track situated near Shanghai is only processing one-quarter of the passengers that its designers envisioned.
Maglev trains still have the capacity to inspire people and policy makers. In November 2013, a group of former American politicians including former state governors like George Pataki (NY) and Ed Rendell (PA) were invited by Japanese Prime Minister Shinzo Abe to tour Japanese maglev train facilities in an attempt to spur American investment in the Japanese technology. Talks of an American maglev line which, at least in early stages, would be 50 percent funded by Japan, but more private investment is needed. Still, we’re at least a few steps further along the long road that started with the maglev concept from the early 1900s.