Winterthur railway station
Winterthur is Switzerland's fifth busiest station, and is a major node between Switzerland's largest railway nucleus in Zürich and places in Eastern Switzerland (such as St. Gallen and Schaffhausen), as well as Germany (Munich), and Austria (Vorarlberg). The station is served by trains on Zürich's suburban S-Bahn network, as well as by regional and intercity trains, with most through passenger trains making a stop. It is also connected with Zürich's airport railway station Zürich Flughafen, which can be reached in about 15 minutes about every 8 minutes. Zürich Hauptbahnhof can be reached with up to 16 direct connections per hour and the fastest connection takes only 22 minutes (S12). The station has 9 standard gauge platforms (numbered 1-9).
Zürich–Winterthur railway
The line contains several different route and only the section from Effretikon to Winterthur has no alternative route. Zürich Hauptbahnhof and Oerlikon are connected by three tunnels. Two of them from the above-ground "old" terminus to Oerlikon. In 2014, with the commissioning of the Weinberg Tunnel, trains have run from the newly built underground station to Oerlikon. There are three connections from Oerlikon to Effretikon: via Wallisellen, Kloten and the Airport. The Zürichberg line, which runs from the Hauptbahnhof via Stadelhofen to Effretikon, is, with a few exceptions, only used by S-Bahn trains.
This was the first connection between Zürich HB and Oerlikon. It was opened on 26 June 1856 and still ran at that time over a ramp to the Limmat Bridge. This ran along the route now occupied by the street of Röntgenstrasse, which explains its sweeping course. Because this ramp was too steep for the locomotives of the period, it built the Aussersihl Viaduct ("Aussersihler Viadukt") from the station approach; this has a more moderate slope due to its curved route. When it was built, it was the longest railway bridge in Switzerland at 834 metres. After running over a short section on the old line, it reaches the bridge over the Sihlquai and the Limmat. The two bridges together are also called the Wipkingen Viaduct ("Wipkinger Viadukt"). After the bridge, the line passes through Zürich Wipkingen station and then immediately runs through Wipkingen Tunnel, after which it continues for some distance in an open cutting, where it merges with the Käferberg line and finally reaches Zürich Oerlikon station. Although it was planned from the beginning as a double-track line, two-track operations only started on 30 May 1860. It has been electrified since 1925 and electrical operations started on 6 August of that year. The section is used by some long-distance trains and line S24.
The Käferberg line, named after the Käferberg Tunnel, is the second connection between Oerlikon and Oerlikon and the Hauptbahnhof. It was opened on 1 June 1969 as a direct connection between Oerlikon and Altstetten for freight trains. On 23 May 1982, double track was opened on the Hardturm Viaduct ("Hardturmviadukt") connecting the Hauptbahnhof to Hardbrücke station, which initially had only had two platform edges on the ramp to the Hardturm viaduct. With the construction of the S-Bahn line between the Hauptbahnhof and Altstetten, two more platforms were added. Since the commissioning of the Zurich S-Bahn in 1990, S-Bahn services in the Limmat valley have also stopped at Hardbrücke. The Käferberg line is used by the trains of lines S5, S6, S7 and S16.