The type Bpm51 second-class coaches, which were originally supplied between 1972 and 1978, are being refurbished at SBB's Bellinzona and Olten works in a SFr 61m ($US 62.7m) programme.

The project includes reconditioning of the bogies, installation of new seats, a new emergency braking system, and installation of power-operated door, as well as corrosion repairs and repainting. The work will allow the vehicles to remain in service until at least 2018.

SBB is implementing a range of short-term measures in an effort to cope with continuing ridership growth. Last year SBB services were used by an average of 977,000 passengers per day, a 2.7% increase over 2010 levels.