As a vision of the future it is a little underwhelming. A battered shipping container sits on top of a black platform that straddles a 130m (400ft) raised track. As I climb into the metal box, I note there are no seats and very little to hold on to.
I am still excited though, as I am about to ride the only magnetic levitation, or Maglev, train in the United States, owned and operated by General Atomic.
A red light flashes, there is a jolt and then a sense that we are floating...because we are. The platform beneath the cargo container I am in is being buoyed up and moved along by powerful electromagnets, allowing the train to move with low friction and no moving parts. As we move off, there is hardly any sound. A gentle whine is the only indication of the current flowing through the track below, and the main noise we can hear is trucks on the nearby freeway. As the shipping container gathers speed, the wind blows through the open doors and the ride is smooth and effortless. Just 20 seconds later we are at a standstill, but it is enough to help me understand why proponents believe Maglev systems are the future of trains and high-speed, long-distance travel.
Maglevs are not a new idea. Patents for high speed transportation systems were granted as early as 1907, but it was not until 1984 that the first commercial maglev system was opened at Birmingham international airport in the UK. The 600m (2,000ft) track ferried passengers at 40 km/h (25 mph) for 11 years before it was closed because of maintenance problems. Since then, higher speed prototypes have also been shown-off, with a train in Japan (JR-Maglev) setting a world speed record of 581km/h (361mph) in 2003. But high start-up costs and the dominance of cheap and reliable trains, planes and cars means there are just two commercial systems operating today, one in China and one in Japan.
But that could soon change. As roads become more and more gridlocked, and air travel become more and more plagued by delays, security and environmental concerns, governments are looking to technologies like Maglev as part of the transport mix.
Levitation trick
All Maglevs operate on a similar – and simple – principle. If you have ever played with bar magnets you will probably remember that opposites attract, but if you flip one of the magnets around, then “like” poles repel. That is what keep the mass of a train – or shipping container - floating several millimeters in the air, cutting down on friction and allowing it to travel much quicker than traditional engines. That same magnetic force can also be used to move it forwards.
“All of the propulsion forces come from electromagnetics, as well as the levitation and guidance forces. The trains are entirely magnetically levitated, driven, and guided” says Dr Sam Gurol, director of transportation programs at General Atomics in the US.
But, whilst all systems are based on the same principle, there are lots of different approaches to getting the train to float and move.
Electromagnetic Suspension (EMS) is the most common form of maglev and is the type used in the Chinese system that zips passengers at more than 400km/h (250mph) between Shanghai and Pudong airport. In most cases, C-shaped arms underneath the train wrap around a guideway. Electromagnets mounted on these arms lift it above a steel track when they are energised. This type of train has the advantage that they can levitate when stationary. Controls monitor and correct the levitation height to between 10 and 15mm, as tiny differences can have a huge effect on the magnetic force.
