Several transit systems in different countries around the world use linear induction propulsion. A wide "center rail" between the running rails serves as the stator for a linear motor.
SkyTrain in Vancouver BC is the most notable linear-induction rail transit system in the western hemisphere in terms of route mileage, full automation and 30+ years of service. Several modern linear-induction transit systems are operating in Asia, particularly Japan, also China, Korea and Malaysia.
https://en.wikipedia.org/wiki/...ardier_Innovia_Metro
The original versions of Innovia Metro were based on a linear induction motor (LIM) using vehicle-mounted windings and a track-mounted stator consisting of a thin aluminum plate mounted flat between the tracks. The small size and flat shape of the motor, and its lack of a transmission connected to the bogies, allows the ART to be much closer to the ground than a traditional subway car. The motor is used for all control with the exception of emergency braking using conventional shoes in the bogies.
Perhaps we can modernize our 3-rail model trains by making the center rail wider ?
Above: Kelana Jaya Line in Malaysia. Below: Vancouver BC SkyTrain
