In order to increase the speed at which rail vehicles may travel, as well as reduce the wear and degradation of performance which accompanies any form of mechanical contact, the ‘new breed’ of railed transportation no longer relies upon wheels save at low velocities. These new designs literally ‘fly’ along their guideways, propelled by the electromotive force generated by alternating-current magnets embedded in the guideway reacting with opposing magnets within the vehicle itself. MagLev (Magnetically levitated) train designs are supported by additional magnets either above or below their guideways, providing a rapid rate of travel without the need for direct mechanical contact with the guideway.
A variety of options have been considered and discarded since the original discovery of this form of travel at Stanford University. The majority of the designs nearing commercial viability rely on one of two basic formats: either attractive levitation or repulsive levitation of the vehicle. Air-cushion designs using ducted fans to force air beneath inflatable skirts for levitation, relying on their electromagnetic systems for propulsion alone, were attempted both in the US and Japan in the late 1960’s as well as early 1970’s and attained speeds in excess of 260 miles-per-hour in test runs; however, advances in air-traffic control systems allowing increased density of commercial air travel ended the research into such systems as the US Tracked Air Cushion Vehicle (TACV) and the early Japanese MLU-series vehicles.
An alternate design modelled after the Hawai’ian Proa outrigger sailcraft from my homeland utilizes pneumatic-support in a static-lift system using wing-in-ground-effect aerodynmic support. In this format, a fixed-wing vehicle is accelerated by an electromagnetic system in order to pass close above the ground (in this case, above the guideway), creating a buildup of high-pressure air beneath the plenum which in turn provides support of the vehicle without requiring onboard lift-generating engines or inflated skirts which introduce additional drag on the system at higher operating speeds.
This design places the vehicle’s onboard magnets as far from the passenger compartment possible, locating permanent magnets in the sponsons at the ends of the plenum array. As the electromotive force is not required to hold the vehicle clear of its track, instead functioning merely to accelerate the vehicle along its path, the strength of the electromagnets set into the guideway should be of a lower order than that found in other current designs.
The original wood and paper model disintegrated at less than 90 mph due to environmental conditions, yet proved the basic design functional. A slight tendency to dip the bow was also noted at higher speeds. True aerodynamic optimization was minimal on the prototype due to the crudity of equipment accessible for its manufacture. As a result, the renderings are intended not to illustrate the precise external configuration but rather merely to illustrate the concepts presented herein.
I have since refined the plenum design somewhat to allow for variable-angle wing modules capable of providing lift at low speeds and closing to form a sealed plenum volume for sustained flight. The addition of small canard-style wings at the bow and an elevated tail lifting surface stabilized pitching and dipping at scale speeds. Further refinement of the sponsons allows this design to fold its wings upwards along the vehicle body to facilitate light-rail use over conventional railways using auxilliary electric motors and onboard batteries to accomodate transitional use as WIG-levitant tracks are built up.
A more complete description of this design is available on my personal blog: http://www.kkhausman.com/2012/06/05/magnetically-propelled-wing-in-ground-effect-vehicle/