Uetliberg railway line

The Uetliberg line shares a common terminus with the Sihltal line, utilising a dedicated underground island platform (tracks 21 and 22) at Zürich Hauptbahnhof station. There is no rail connection to the rest of the station, but the platform is served by the same complex of pedestrian subways and subterranean shopping malls that link the station's other platforms.[1]

From Hauptbahnhof to Zürich Giesshübel station the two lines share a common twin-track line, initially in tunnel, partly running along and under the Sihl river. The current Selnau station is located in this under-river tunnel section.[1]

Although the two lines diverge at Giesshübel station, and the depot for Uetliberg trains is located there, Uetliberg line trains do not stop. Just beyond Giesshübel, the line serves Zürich Binz station. The line then commences a long, steep but relatively straight climb through the Zurich suburbs, serving the stations of Zürich Friesenberg, Zürich Schweighof and Zürich Triemli. This section of line is single track, with a double track section between Binz and Friesenberg.[1]

Triemli station is adjacent to the Triemli Hospital, one of Zürich's main hospitals, and is the terminus for some trains on the line. The station previously had two tracks and two platforms.[1] Due to accessibility requirements, the island platform and the second track were removed in 2018. [12]

Beyond Triemli the line enters a more wooded and hilly environment, and executes a broad U shaped route to the summit of Uetliberg, which is 5.9 km (3.7 mi) from Triemli by rail, but only 1.5 km (0.93 mi) away in a direct line. This section of line serves Uitikon Waldegg and Ringlikon stations, and is single track, with double track sections between Triemli and Uitikon Waldegg, and at Ringlikon.[1]

Uetliberg station lies some 650 m (2,130 ft) from, and 56 m (184 ft) below, the summit of the Uetliberg. The station has two terminal tracks, and a substantial station building, including a restaurant.[1]

• S10 Zürich HB – Zürich Triemli – Uetliberg

The passenger services on the line now forms part of the Zürich S-Bahn, branded as the S10. Standard Zürcher Verkehrsverbund (ZVV) zonal fare tariffs apply to the line. On working days, trains run every 30 minutes from Hauptbahnhof to Uetliberg, with a more frequent shuttle service between Hauptbahnhof and Triemli. On Saturdays, Sundays and public holidays, trains run the full length of the line every 20 minutes. A journey over the full length of the line takes 20 minutes.[5][13]

Be 556 524 of the Uetlibergbahn in the snow. The offset overhead line and pantograph can be seen.

The Uetliberg line is constructed to standard gauge and uses overhead lines for electrification. Both it and the Sihltal line, with which it shares right-of-way between Zürich HB SZU and Zürich Giesshübel, are electrified at 15 kV AC.[10]

Prior to August 2022 the Uetliberg line used 1200 V DC. To allow both lines to operate over the shared section, the Uetliberg line used an overhead line offset from the centre of the track, and its cars were equipped with specially designed pantographs to collect from this.[14]

The line's branding makes play on its gradient

The Uetliberg railway's DC electrification system requires its own fleet of DC equipped trains. Until about 2014 most of the trains were operated by three car sets, with two Be 4/4 motor coaches from the series 521–528 sandwiching a low floor intermediate trailer. The two older Be 8/8 cars 31 and 32, with no low floor access, were used for short workings, reversing at Triemli station.[15]

In 2010, six new multiple unit trains were ordered from Stadler Rail, equipped for dual voltage operation so as to operate on both the Uetliberg and Sihltal lines. By August 2013, the first of these units was on trial on the Uetlibergbahn, and by May 2014 they were operating many of the line's services. The new trains are three-section articulated low-floor units, and are classified as Be 510.[15][16] In 2016 rakes of two Be 510 work the trains to Uetliberg, the Be 4/4 521–528 sets having been relegated to the short working and the Be 8/8 sets having been scrapped in February 2016.