Uchikura & Co., LLC

Japan’s Ōedo Line: Moving Through Tokyo by Magnetic Force

 

Did you know that Tokyo’s Ōedo Line（大江戸線）moves differently from most trains?

 

On a conventional electric train, motors turn the wheels to move it along the rails. The Ōedo Line uses a linear motor, which produces electromagnetic force between equipment beneath the train and a reaction plate installed between the rails. That force propels the train forward.

 

It still has steel wheels that roll on rails. Unlike a floating maglev train, the Ōedo Line stays firmly on the track. The difference is how it generates its driving force.

 

This system allows smaller trains and tunnels while accommodating tight curves and steep slopes—useful features when building a railway beneath an already crowded city.

 

And the Ōedo Line runs deep. Its Roppongi Station platform is 42.3 meters below ground, roughly equivalent to putting a 14-story building underground. The line had to pass beneath existing railways, rivers, and other infrastructure.

 

Passengers may simply see another subway train. Beneath their feet, however, a different kind of motor is doing the work.

 

For me, that is part of what makes Japan interesting. Even an ordinary subway ride can reveal an engineering idea you never knew was there.