The services expanded as part of the 4th phase of expansion will need more vehicles. The ZVV and SBB are therefore putting new trains onto the railway. But the old generation of S-Bahns will also be refurbished.
New rolling stock
SBB has ordered around 50 of the latest 3rd generation double-decker trains (Regio-Dosto) from Stadler Rail for use in the Zurich S-Bahn. These will be put into operation in stages by 2018. The first trains have been running on the Zurich S-Bahn network since the start of 2012. The new trains are 150 metres long and thus 50 metres longer than the models currently in use.
Modernisation of the first generation of S-Bahns
The 1st generation of 113 double-decker trains (DDTs) is also going to be optimised. By 2017, one intermediate car will be replaced by a new low-floor double-decker car (LFDD) respectively. At the same time, these intermediate cars will also be modernised: They will be given air conditioning, freshly reconditioned interiors and generous entrance zones. All 113 DDTs will be completely gutted and rebuilt. In addition to rust removal and repainting the carriage bodies, energy saving measures will also be implemented so that the trains will become more environmentally friendly. The carriages this frees up can be used to form new relief trains.
The fleet will be supplemented by 61 2nd generation double-decker trains (DDTs). These have a low floor entrance and air conditioning.