Diesel Locomotive

The modern diesel locomotive is a self contained version of the electric locomotive.  Like the electric locomotive, it has electric drive, in the form of traction motors driving the axles and controlled with electronic controls.  It also has many of the same auxiliary systems for cooling, lighting, heating, braking and hotel power (if required) for the train.  It can operate over the same routes (usually) and can be operated by the same drivers.  It differs principally in that it carries its own generating station around with it, instead of being connected to a remote generating station through overhead wires or a third rail.  The generating station consists of a large diesel engine coupled to an alternator producing the necessary electricity.  A fuel tank is also essential.  It is interesting to note that the modern diesel locomotive produces about 35% of the power of a electric locomotive of similar weight