Introduced from 2002 onwards, they share design characteristics with the successful Eurosprinter range of electric locomotives, also built by Siemens.
[5] The locomotive is designed to be made of as few parts as possible, and is of modular construction, with separate components (engine, electronics etc.)
[6] Marketing by Siemens has heavily emphasised the locomotive's energy-saving characteristics, as well as the technology used to reduce particulate emissions.
The locomotives have a supercharged 16-cylinder diesel engine of the MTU 4000 series developing 2,000 kW of power which drive a three-phase brushless alternator.
In addition the electrodynamic brakes can charge both a battery pack, as well as high capacity capacitors – meaning that energy absorbed on deceleration can be reused later on.
This feature saves emissions and fuel consumption[7] – if the batteries and capacitors are full, a roof-mounted set of resistors provides the remainder or additional rheostatic braking.
required for passenger operation was carried under the locomotives frame between the bogies and necessitated a reduction in the size of the fuel tank.