S23 (ZVV)
The S23 is a regional railway line of the Zürich S-Bahn that operates only during rush hour.
At, trains of the S23 service usually depart from underground tracks 41–44.
Route
The service calls only at major stations between Zürich and Romanshorn on the shores of Lake Constance. Only some trains operate between Winterthur and Romanshorn, while others have Winterthur as their terminus.Zürich Hauptbahnhof- ''''''
Scheduling
The S23 operates during peak-hours only: five trains from Winterthur to Zürich HB in the morning, and four trains from Zürich HB to Winterthur in the evenings. The journey between Zürich and Winterthur, including the sole intermediate stop in Stadelhofen, requires 24 minutes. Zürich to Romanshorn requires 69 minutes.Rolling stock
Services are operated by two refurbished Re 420 locomotives pushing or pulling double-deck passenger carriages.History
The S23 was introduced in the timetable revision of December 2015 as a peak-hour service between Zürich HB and Winterthur. The S23 supplemented the S11, then a peak-hour service between and Winterthur, and the S12, which operated on an hourly schedule and was "notorious" for overcrowding. Some S23 services continued to Romanshorn.At the time of its introduction the S23 was the only service on the Zürich S-Bahn whose carriages were not air-conditioned, leading to complaints from passengers during the summer months.