Distributed Power - Other Similar Operations

Other Similar Operations

'Top and tail' is a phrase used to describe an operation where there is a locomotive at each end of the train; usually to make it easier to change direction at a terminal location where it is not possible to run the motive power 'around' the train (i.e. swap the locomotives from one end of the train to the other); this arrangement is not used specifically to operate longer or heavier trains.

The description should not be confused with 'push-pull', which refers specifically to a train configuration in which the motive power is located at one end of the train only. In this latter configuration, the train is able to be operated from the 'non-powered' end by use of a engineer's control position (the 'cab-car') located at that end of the train. Push-pull operation is usually associated with passenger trains.

'Top-and-Tail' is not, strictly speaking, a Distributed Power operation although such a configuration could, conceivably, be used as such. The remote control of a Top-and-Tail configuration is mentioned above (Western Australia) in which Locotrol technology is utilised to provide a solution although not in the context of increasing the train size. The term 'Distributed Power' has been specifically coined to convey the generic concept of removing some of the motive power of a train from its head-end and distributing it within or throughout the length of the train to reduce coupler forces (and, when competently operated; in-train dynamics) and permit the operation of longer, heavier trains. Use of this term ensures that the brand-name 'Locotrol', which is the property of one company, is not itself used generically to refer to the technology of distributed power.