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.[1]

International Rhine Regulation Railway
The railway bridge at Kriessern, photographed from Switzerland with Austria in the background
Overview
Locale	Austria, Province of Vorarlberg Switzerland, Canton of St Gallen
Technical
Line length	25 km (16 mi)
Track gauge	750 mm (2 ft 5 1⁄2 in)
Electrification	750 V DC
Route diagram Mouth of the Rhine into Lake Constance Lustenau depot Vorarlbergbahn Wiesenrain Unterklien quarry Widnau depot Straßenbahn Heerbrugg–Diepoldsau (until 1956) Kadelberg quarry Koblach Kolbenstein quarry Montlingen

As its name suggests, the railway's original purpose was to assist in the engineering works needed to regulate the Rhine in this area - the so-called Rhine Regulation. 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.[2]