International Rhine Regulation Railway

The International Rhine Regulation Railway (German: Internationale Rheinregulierungsbahn) was an industrial railway situated on both banks of the Alpine Rhine river to the south of its outfall into Lake Constance. Large parts of the line have been preserved. As this stretch of the Rhine forms the international boundary between Austria and Switzerland, the railway is located in both countries.

As its name suggests, the railway's original purpose was to assist in the engineering works needed to regulate the Rhine in this area. It is constructed to 750 mm gauge (2 ft 5 ¹⁄₂ in gauge) and is partially electrified at 750 V DC using overhead lines.