magnets are positioned along each side of the maglev vehicle. These
magnetically interact with permanent magnets on the guideway to
provide levitation and lateral guidance. The magnetic polarities
of the vehicle and guideway magnets generate repulsive magnetic
forces that suspend the vehicle and push it toward the center of
the guideway. The suspension automatically opposes any external
force (wind, grades, curves, etc.) that tries to displace the vehicle
from its equilibrium position.
Small-scale permanent magnet maglev vehicles have been built and
operated. However, for practical, long distance transport systems,
permanent magnets are not practical. The cost of permanent magnet
guideways is too great. Moreover, the clearance between the vehicle
and the guideway is a fraction of an inch. The cost of constructing
a guideway to the requisite tolerances, its vulnerability to foreign
objects (trash, wind borne debris, etc.) and the problems of ice
and snow buildup, make it impractical for high speeds travel.