| Operator: | BLS AG |
| Stops: | 20 |
| Distance: | 63km (39miles) |
| Journeytime: | 1 hour 4 minutes |
| Frequency: | Every 30 minutes |
| Stock: | BLS RABe 515 |
| Map State: | collapsed |
The S1 is a railway service of the Bern S-Bahn that provides half-hourly service between and via . BLS AG, a private company primarily owned by the federal government and the canton of Bern, operates the service. The S1 is the oldest of the Bern S-Bahn routes, tracing its roots back to 1987.
The S1 operates every half hour between and via . In Fribourg, the S1 makes a connection with the IC 1 or IR 15 for . In Thun, the S1 makes a connection with the IC 6 or IC 8 for and . The S1 is joined between and by the S2, for a total of four trains per hour between those stops. The S2 makes local stops between and, which the S1 skips.[1], most services are operated by BLS RABe 515 multiple units.[2]
Swiss Federal Railways (SBB) had run trains on a half-hourly schedule over the Lausanne–Bern and Bern–Thun railway lines since 1987. Trains ran between Thun and Flamatt every 30 minutes, continuing to either or Fribourg.[3] The service gained the designation "S1" on 28 May 1995 when the S2 began operating.[4]
The S1 has continued relatively unchanged since then. The Bern-Lötschberg-Simplon-Bahn (BLS) assumed operation from the SBB in December 2004, and the S11 began running as a rush-hour supplement between Bern and Fribourg.[5] Beginning in December 2008, the S11 was eliminated, and the S1 ceased serving Laupen BE: all trains continued to Fribourg on a half-hourly schedule. The re-routed S2 took over service between Flamatt and Laupen BE.[6]