Keihin-Tōhoku Line
The contemporary Yamanote Line came into being on 19 November 1956 when it was separated from the Keihin-Tōhoku Line and given its own set of tracks along the eastern side of the loop between Shinagawa and . However, Yamanote Line trains continued to periodically use the Keihin-Tōhoku tracks, particularly on holidays and during off-peak hours, until rapid service trains were introduced on the Keihin-Tōhoku Line in 1988.