). While nothing is specified about this, in the real world most high-speed diesel locomotives are in fact a combination of diesel-powered electric generators and electric traction motors. Given the speeds our Factorio trains reach, it's probably safe to assume our locomotives are in fact diesel-electric. Wouldn't it be nice to be able to hook this generator up to the electric grid to jumpstart a new outpost (hook up a roboport to the locomotive and deploy a blueprinted solar plant 
)For balance purposes: fuel economy would probaby be rather poor. Possibly the locomotive would suffer some damage from being (ab)used in this way (after all, the engine was probably designed to be partially air-cooled by virtue of wind)