A KiwiRail "DX" class diesel-electric locomotive double-heading a freight train at National Park station, New Zealand. The "DX" class, also known as "Dixies", are the most powerful diesel locomotive type on the New Zealand rail network (and second only to the electric "EF" class as most powerful overall), and can be found working both freight and passenger services.

Class: DX
Wheel Arrangement: Co-Co
Manufacturer: General Electric, United States
Power output: 2,240kW
Built: 49
In Service: 46
Operator: New Zealand Railways / KiwiRail

http://en.wikipedia.org/wiki/NZR_DX_class