The
Magplane System
Magplane uses individual passive vehicles, levitated above a magway
trough of semi-circular cross section. Vehicles are propelled by a
linear synchronous motor winding in the magway and controlled by a
central computer.  The
vehicles are supported resiliently on a magnetic cushion, and are
free to roll ten degrees in either direction from the bank angle of
the magway. This enables them to negotiate horizontal curves of 2 km
radius at 360 km/h with airplane comfort. Coordinated self-banking
also permits vehicles to negotiate vertical curves typical of
highway alignments without passenger discomfort by a "chandelle"
type of maneuver in which negative vertical gee-forces are canceled
by horizontal curvature. The maximum size vehicle weighs 45 tonnes
gross, and carries 175 passengers, three and two abreast. Minimum
headway at 500 km/h is 20 seconds, which permits a maximum single
vehicle operation capacity of 25,000 seats/hour in each direction,
as compared to about 10,000 for light rail and about 3,000 for a
highway lane. With headways of 60 seconds in keeping with current
state-of-the-art automatic controllers, three coupled intercity
vehicles would be used to achieve the 25,000 seats/hour intercity
capacity.
The magway structure is a curved box girder whose upper surface
forms a trough of aluminum sheet with an open slot at its center. A
meander-shaped propulsion winding occupies the center slot. Vehicles
carry permanent magnets.  Levitation
forces, guidance forces, and righting moments are exerted by
currents induced in the magway surface by the motion of the vehicle
magnets. Propulsion forces are produced by AC current in the
guideway propulsion windings which generate a traveling wave. The
vehicle rides this wave like a surfboard. Wayside power conditioning
units spaced at 2 km intervals, synchronize the traveling wave with
the vehicle, and generate active damping forces on the basis of
position and acceleration information transmitted from vehicle
sensors. Vehicles can leave and re-enter the magway at full speed to
stop at off-line magports. The Magplane system thus achieves
continuous traffic flow similar to highways, rather than the batch
flow process of railroads with on-line stations.
Because magways carry only vehicles with low footprint pressure they
can be significantly lighter and less expensive to build and
maintain than railroad tracks. They need to carry only 1/20th the
live load and provide 1/10th the wayside power (6 MW instead of 60),
and can be compatible with the curves, grades, overpass, and
right-of-way requirements of highways. Because of the large
clearances possible with the Magplane concept, magways do not
require high stiffness and accuracy of alignment or of banking.
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