A narrow-gauge railway is a railway with a track gauge narrower than 1,435 mmstandard gauge. Most narrow-gauge railways are between 600 mm and 1,067 mm.
The narrow-gauge railways in Saxony were once the largest single-operator narrow-gauge railway network in Germany. In Saxony, the network peaked shortly after World War I with over 500 km (311 mi) of tracks. At first, it was primarily created to connect the small towns and villages in Saxony – which had formed a viable industry in the 19th century – to already established standard-gauge railways. But even shortly after 1900, some of the railways would become important for tourism in the area.
The Deutscher Eisenbahn-Verein or DEV was founded in November 1964 as the Deutscher Kleinbahn-Verein. Its purpose was the preservation of a working branch line with all its installations as a living open-air museum. The term Kleinbahn was primarily a Prussian concept that referred to light branch lines with lower traffic demands and of more lightweight construction than main lines or normal branch lines, hence the Kleinbahnen were mainly found in northern Germany.
The Märkische Museum Railway or MME is a German railway society that was founded in order to show narrow gauge vehicles in operation on small branch lines.
The DB Class V 51 and DB Class V 52 are classes of almost identical narrow gauge 4 axle diesel hydraulic locomotives built in 1964 for the Deutsche Bundesbahn, being built for 750 mm and 1,000 mm gauge lines respectively.
Steam traction was the predominant form of motive power used by the Deutsche Reichsbahn on its narrow-gauge railways. For certain duties diesel locomotives were also used, albeit these were usually second-hand or rebuilt engines.
The Busenbach–Ittersbach railway is a line in the northern Black Forest in the German state of Baden-Württemberg. The mostly single-track and continuously electrified line branches in Waldbronn-Busenbach from the Alb Valley Railway —with which it is closely linked operationally and historically—and runs as a branch line to Ittersbach. The Albtal-Verkehrs-Gesellschaft is responsible for the railway infrastructure and is the only company operating on the 14.4 kilometre-long line. Originally the Busenbach–Ittersbach railway was operated together with the Ittersbach to Pforzheim line, which later became the Pforzheim Light Railway. The whole line from Busenbach to Pforzheim was initially built to 1,000 mmmetre gauge, later the section from Busenbach to Ittersbach was rebuilt to 1,435 mmstandard gauge and the Pforzheim Light Railway was closed. The line has been operated as part of line S 11 of the Karlsruhe Stadtbahn since 1994.
The first railway in Austria was the narrow-gauge line from Gmunden in the Salzkammergut to Budweis, now in the Czech Republic, this was 1,106 mm gauge. Some two dozen lines were built in 760 mm gauge, a few in 1,000 mmmetre gauge gauge. The first was the Steyrtalbahn. Others were built by provincial governments, some lines are still in common carrier use and a number of others are preservation projects. The tramway network in Innsbruck is also metre gauge; in Linz the rather unusual gauge of 900 mm is in use.
A few narrow-gauge railway lines were built in Denmark, the majority in 1,000 mm gauge. Most railway lines in Denmark were built with standard gauge from the beginning, since the country was fairly densely populated in the 19th century.
There are hundreds of kilometres of 600 mm, 750 mm, 785 mm, and 1,000 mm narrow-gauge lines in Poland. The metre-gauge lines are mostly found in the northwest part of the country in Pomerania, while 785 mm lines are found only in the Upper Silesia region. 750 mm is the most commonly used narrow gauge; it is used, for example, in the Rogów Narrow Gauge Railway and in Tarnowskie Góry with the world's oldest narrow-gauge railway in continuous service since 1853. Some narrow-gauge lines in Poland still operate as common carrier, while others survive as tourist attractions. One of the finest of the latter is the 600 mm narrow-gauge railway running from Żnin via Wenecja and famous Biskupin to Gąsawa in the Pałuki region. Railway traditions of Pałuki date back to July 1894 when the first two lines were opened.
In Spain there is an extensive 1,250 km (780 mi) system of 1,000 mmmetre gauge railways. The majority of these railways was historically operated by FEVE,. Created in 1965 FEVE started absorbing numerous private-owned narrow-gauge railways. From 1978 onwards, with the introduction of regionalisation devolution under the new Spanish constitution, FEVE began transferring responsibility for a number of its operations to the new regional governments. On 31 December 2012 the company disappeared due to the merger of the narrow-gauge network FEVE and the broad-gauge network RENFE.
Numerous industrial narrow-gauge lines were built for peat extraction, clay extraction for brickworks and construction sites. The dominant gauge for industrial lines was 700 mm, contrary to the 600 mm gauge used in neighbouring countries.
Between 1917 and 1930 approximately 300 km of military and industrial narrow-gauge railways were built at the gauge of 600 mm and 750 mm or Bosnian gauge, built by Austria-Hungarians and Italians, intending to create a through route from Skopje and Tetovo to the Adriatic coast of Albania. None of these railways remained intact.
Around 1935, Latvian narrow-gauge railways consisted of 536 km of 600 mm gauge, 432 km of 750 mm gauge, and 48 km of meter gauge.
Lithuania has 158.8 km of 750 mm narrow-gauge railway lines remaining, although only 68.4 km of them are regularly used, employing 12 locomotives. They are included in the Registry of Immovable Cultural Heritage Sites of Lithuania.
The vast majority of Finnish narrow-gauge railways were owned and operated by private companies. There are only a few instances where narrow-gauge railways were in direct connection with each other, and those interchanges did not last for long. The railways never formed a regional rail traffic network, but were only focused on maintaining connections between the national Russian-gauge railway network and the off-line industries.
Most Slovenian railway lines were built during the Austro-Hungarian Empire.
Europe inherited a diversity of rail gauges. Extensive narrow-gauge railway networks exist in Spain, Central Europe and Southeastern Europe.
Metre and 3 ft gauge lines are found in South America. Some of the 1,000 mm gauge lines cross international borders, though not as efficiently as they might.
