JNR 203 series

Data (as of 29 Jul 2023)

History

The 203 series was a commuter train type for Joban Line (Local) and through-service to Tokyo Metro Chiyoda Line, consisted of ten coaches. In the 1970s, TRTA (now Tokyo Metro) had been dissatisfied with 103 series that Japanese National Railways used for the through-service because it was far more energy-consuming than TRTA's own rolling stock, and generated too much heat despite having no air-conditioning. Furthermore, the 103 series did not always fit with underground tunnels so that it often broke down. Therefore, JNR had to develop a new train even amid the severe financial crisis.

Traction and braking systems of the 203 series were based on those of 201 series, but the body was made of aluminium to make the train light enough to run the underground with steep gradients. Bogies of those introduced after 1985 were based on 205 series as well.

The 203 series had consistently been used on Joban Line (Local) and Tokyo Metro Chiyoda Line but not on Odakyu lines. JR East replaced all of them with E233 series in 2010-11. Many carriages were exported to Indonesia and the Philippines.