There have been three major line deviations. The first between Kinomoto and Tsuruga involving the 5,170 m Fukasaka tunnel opened in 1957 as a new line, with the original line remaining in service until the second new line opened in 1965, including the Shin-fukasaka tunnel at 5,173 m and a spiral section partially in tunnels to ease the ruling grade on the climb from Tsuruga to Biwako.
