The first hybrid bus with electric drive technology from Siemens is now running as a traditional double-decker bus round London. The customer is London City Transport who run the bus on route 141 to London Bridge. In comparison with the conventional diesel city bus, the hybrid double-decker releases 40% less emissions into the environment and saves approximately 30% of the fuel.

The powertrain consists of generators, converters, drive motors and gear elements as well as an intelligent drive control including energy management. Two Siemens 1PV5138 drive motors get the bus going. The motor torques act on a Flender addition gear which bundles the power of both motors on one drive shaft. Lithium-ion batteries save the produced brake energy and provide it for the next acceleration. The energy management controls the energy flow between the battery and the diesel engine depending on the power required by the drive cycle.