The S40 is a regional railway line of the S-Bahn Zürich on the Zürcher Verkehrsverbund (ZVV), Zürich transportation network, in the cantons of Schwyz, St. Gallen and Zürich.

The line runs from Einsiedeln to Rapperswil via the junction stations of Biberbrugg and Pfäffikon SZ, crossing the Seedamm.

All services use Südostbahn rolling stock.

Media related to S40 line (Zürich S-Bahn) at Wikimedia Commons

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