The last double-decker bullet trains on the Joetsu Shinkansen Line connecting Tokyo and Niigata will be withdrawn from service in a few years, a railway source said Saturday.

East Japan Railway Co. (JR East) plans to replace the E4 series, the last remaining two-deck shinkansen, with the single-deck E7 series from fiscal 2018 to improve speed and comfort, according to the source.

The double-deck carriages of the E4 series, which debuted in 1997, had a seating capacity of 1,634, the largest in the world among high-speed trains.

The E4 series trains initially RUN on the Tohoku Shinkansen Line connecting Tokyo and Aomori, but ended service in 2012.

The E7 series, jointly developed by JR East and West Japan Railway Co., will be introduced on the Joetsu Shinkansen Line from fiscal 2018, while the E4 series trains will gradually be replaced with E7 series carriages, the source said.

The E2 series is still in service on the Joetsu Shinkansen Line as well, but will be replaced by the E7 after the E4 series.