The first trains are due to start test operation on September 19 on Line S31 linking Belp and Münchenbuchsee, and will enter scheduled service on Line S1 (Fribourg – Bern – Thun) in December.

Traffic on the Bern S-Bahn is growing at the rate of 5% a year and by 2025 the network is expected to be carrying 60% more passengers. "The number of seats we can provide will increase by around 30% thanks to the introduction of the new trains," says Mr Andreas Willich, head of passenger traffic with BLS.

Each four-car train is 102.6m long and seats 335 passengers including 61 in first class. The trains are accessible to disabled passengers and have space for three wheelchairs. One of the two toilets on each train is designed for use by people in wheelchairs.

The 160km/h trains are being supplied under a SFr 494m ($US 505.8m) contract awarded to Stadler in March 2010. Delivery of the so-called Kiss trains will continue until the end of 2014.