東海道本線
The Yokosuka Line runs underground between Tokyo and Shinagawa (parallel to the Tōkaidō Main Line, the Yamanote Line and the Keihin-Tōhoku Line) then branches to the west along the Tōkaidō Shinkansen into the city of Kawasaki. (This alignment, technically known as the Hinkaku Line(, ), was originally built for freight usage; see below.) It rejoins the Tōkaidō Main Line corridor near Tsurumi Station and follows the Tōkaidō Main Line to Ōfuna, where it branches off to the southeast along the original Yokosuka Line toward the Miura Peninsula.