Jungfraubahn BDhe4/8 - 214 --- The 3-phase motors of a JB railcar thus operates in a regenerative mode which allows the trains to generate electricity during the descent, which is fed back into the power distribution system. Approximately 50% of the energy required for an ascent is recovered during the descent. It is this generation that regulates the descent speed.
In this picture, two-coupled BDhe4/8 multiple unit train of the Jungfrau Railway with railcar no. 214 in front & 211 behind was coming in with downhill passenger service from Jungfraujoch to Kleine Scheidegg on 14th May 2015. Photo taken Bani Das.