However, the locomotive operates equally well in either direction, and on special order controls may be arranged so that the long hood end is forward, or dual controls may be provided. The locomotive is designed for single unit or multiple unit operation. When coupled together for multiple unit operation, all units are controlled simultaneously, through jumper cables, from the control stand in the cab of the lead unit. The majority of components on a locomotive perform functions relating to one of the following, either the diesel engine or the electrical transmission of power to the driving wheels. The diesel engine is the source of locomotive power.
Storage batteries provide the energy required to start the engine.
These electrical solenoids engage the starting motor pinions with the engine ring gear. When each motor pinion is engaged, battery power is applied to the starting motors to crank the engine. Once started, the engine supplies all power to drive three electrical generators, a multi-cylinder air compressor, and all cooling and engine support systems. The three electrical generators, the direct current traction motors, and the locomotive control system, form the electrical transmission. The auxiliary generator provides excitation current to the D14 companion alternator.