The Forch railway (, FB, Frieda ) is a local railway line in the Swiss canton of Zürich. It is owned and operated by the Forchbahn AG, and is branded as line S18 of the Zürich S-Bahn. The standard Zürcher Verkehrsverbund (ZVV) zonal fare tariffs apply to the line. The line opened in 1912 and links the towns of Esslingen and Forch to Rehalp, an outer suburb of the city of Zürich. From Rehalp, trains continue over the Zürich tram system to a terminus at , outside the Zürich Stadelhofen railway station in central Zürich. The line is built to metre gauge ( gauge). Between Esslingen and Rehalp the line has a length of some , with the continuation over the Zürich tram system adding an extra of route. History The Forch railway line opened on November 27, 1912, with the trip taking 67 minutes. As built, the line from the Zürich city boundary to Esslingen was a single track tramway, largely mixed in with road traffic. At Esslingen, the Forch line connected with the Uster-Oetwil line and, indirectly via that, with the Wetzikon-Meilen line. These two metre gauge tramway lines had both closed by 1950. In 1950 it was proposed that the line should be replaced by buses, and a two-week test bus operation was undertaken with moderate success. The conclusion of the experiment was that retaining the line was the best solution provided that the line could be separated from the street and modernized. In the following decade, separation of rail and road traffic was increased. New bogie rolling stock was acquired, similar to two cars built for the line in the late 1940s. In 1970, a new depot and station was built at Forch, together with a new section of line and underpass under the new main road. Between 1973 and 1976 a tunnel was built under the village of Zumikon, eliminating the street section through that village. In 1976, new Tram 2000 trains were introduced and a regular 15-minute train frequency was introduced. By 1979 the line had been doubled as far as Neue Forch. Projected extensions to Zürich Hauptbahnhof and Wetzikon were under consideration as early as 1979, but have yet to become reality. In 1990, the line was added to the ZVV transportation network, and in 1995 a new terminus was built at Esslingen. In 2004, new low floor cars were acquired from Stadler