However, the conflicting interests of the affected Thuringian states for a long time prevented the implementation of these plans.

The signing of a treaty of 8 October 1870 was signed between Saxe-Weimar-Eisenach, Saxe-Meiningen, Saxe-Altenburg and Schwarzburg-Rudolstadt allowed the granting of a concession on 3 April 1871 to the newly formed Saal Railway Company (Saal-Eisenbahn-Gesellschaft) to build and operate a railway line from Großheringen to Saalfeld via Jena and Rudolstadt.

At first the Saal line was only a route of regional importance, connecting at Großheringen with the Thuringian Railway from Bebra through Erfurt to Weissenfels.

Between 1936 and 1939 Class SVT 137 high-speed streamlined diesel train sets connected Berlin to Munich or Stuttgart, on the Saal line, reaching an average speed on it of 95 km / h. Between 1935 and mid 1941, the line was electrified and thus connected to the electrified networks in central and southern Germany.

Five years later, all components of the electrical equipment and the second line were removed as part of reparations to the Soviet Union following World War II.

Since the route follows the winding course of the Saale, the smallest radius of a curve is 450 metres and the sections where the maximum speed of 120 km / h can be achieved are relatively short.