A research team, lead by Tohoku University's Yusuke Sugahara, has made a prototype of the train-plane which floats just above the ground on a cushion of air.
Since the train does not come into contact with the ground, there is no friction reducing its forward momentum, allowing the vehicle to potentially reach greater speeds than regular trains with less energy expenditure.
It's being called the Aero Train and it's prototype was developed as a proof of concept for a paper given at the IEEE International Conference on Robotics and Automation. It works on the principles of the "wing-in-ground effect," which is that as planes get very low, drag decreases significantly. Take one of these planes and attach some passenger cars to it--voila!--you have yourself a very efficient flying train that doesn't require that much energy to move. Here's a video of the prototype in action, flying just inches above the ground:
Levitation Control of Experimental Wing-in-Ground Effect Vehicle along Z Axis and about Roll and Pitch Axes
The goal of this study is to develop a control method for levitation stabilization of an aerodynamic levitated train named the “Aero-Train,” which is a high-speed, high-efficiency train system. The levitation in this system occurs because of the wing-in-ground effect that acts on a U-shaped guideway. In order to achieve the goal of this study, a small experimental prototype and a control method for stabilization along the Z axis and about the roll and pitch axes were developed, as described in this paper. The effectiveness of the developed control method is confirmed by experimental results.
Solar panels are placed on the guide-way's roof, while wind generators are placed alongside in those places where wind energy is generally available. The generated electricity can be fed to the train directly or stored in its on-board batteries. The researchers expect the system to generate much more energy than is consumed by the Aero-Train, thereby making it double as an electric power plant.
The next stage in the development is to build a larger Aero-Train prototype with room for six passengers and a maximum operating speed of 350 kilometres per hour (217 mph). The final, full-scale Aero-Train, with a length of 85 metres (279 ft) and seating capacity for 325 passengers, is aimed to begin service in 2020.
China's Shanghai Maglev Train already zips around the country without relying on rails, instead using high-powered electromagnets to levitate the train as it zooms across the track at 268 miles per hour.
Although this rail-less technology cuts down on the friction that leads to lost energy, MagLev trains still create wind drag between the track and the bottom of the train, making them less efficient and more costly.
The Aero-train's concept actually embraces this wind drag, using the ground-effect principle's fast-moving air beneath the train to propel it down the track.
Eventually, the researchers hope to scale up the model to a manned train capable of speeds of 200 kilometers per hour and test it in a more controlled track. The team’s ultimate goal is to somehow incorporate the technology into a large commuter rail system called the Aero Train, which is depicted above.