The new trains will replace a mixture of locomotive-hauled trains and modernised EMUs, most of which will be more than 40 years old by 2019.
Full details regarding the new trains will be revealed by SOB once contractual procedures are completed. In its September 2015 tender, SOB stated it was seeking six trains for the Voralpen Express services plus a further five for regional services. The financing for the new trains was agreed in 2014 by the Swiss federal government and the cantons concerned.
The new trains will have more space for bikes, luggage and skis than the existing trains but will not have buffet cars. The interiors for the new trains will be based upon feedback from existing passengers via online surveys.
In December 2013 the Voralpen Express became the sole responsibility of SOB after Swiss Federal Railways (SBB) sold all its shares in the venture to SOB for SFr 4.2m.