The two designs are also now fully certified to the European Locomotives and Passenger Rolling Stock subsystem Technical Specification for Interoperability (TSI Loc & Pas), which will provide a basis for certifying the locomotives for operation in other European countries.

Vossloh says that compliance with these certification requirements means the G12 and G18 have series production approval until December 2020, after which an extension can be applied for. For locomotives without TSI Loc & Pas this approval comes to an end in mid-2017.

The G12 and G18 have a maximum output of 1.2MW and 1.8MW respectively, and both types use MTU's 8V 4000 R43 engine, which is compliant with EU Stage 3b emissions regulations.

Vossloh says the approval lays the foundation for expanding its range of four-axle diesel locomotives.