The 15kV 16.7Hz ac train, which has been branded Cityjet eco by ÖBB, will be used on passenger services which operate over a mixture of electrified and non-electrified infrastructure.

The prototype train (No. 4746 049) has been taken off the current Cityjet EMU production line and is almost identical to a conventional class 4746 EMU. The additional equipment is located on the roof of the intermediate trailer vehicle so there is no reduction in the size of the passenger area and the axleload can be kept within the 17-tonne limit.

Three battery modules with a total capacity of 528 kWh are mounted on the roof alongside associated cooling and electronic equipment. The Lithium Titanate (LTO) battery cell have an estimated lifecycle 15 years.

In battery mode maximum speed is 120 km/h and acceleration is 0.77 m/s², which compares with 160 km/h and 1.0 m/s² in electric mode.

The Cityjet eco is part of ÖBB’s strategy to achieve zero emission traction across the whole fleet by 2035.

The train will go on display at InnoTrans in Berlin next week (track 1/400) before undergoing trials on all non-electrified ÖBB lines. Siemens aims to gain authorisation for passenger operation by Spring 2019.