Figure 2.5. FourWheel Swivel Truck.
The auxiliary generator provides the power needed to operate control
equipment, to charge the storage battery, and to supply current for the
train's lowvoltage circuits. A steam generator is needed on passenger and
ambulance trains for coldweather heating of cars. The air compressor, with
its twocompression cycle, compresses air which is stored in the main
reservoir. Air for the train's braking system is supplied from this source.
A dieselelectric locomotive has both fuel and water tanks. The fuel
tank contains the fuel oil for operating the engine. The waterexpansion
tank is part of the engine cooling system, designed to carry off the excess
heat of the engine. Trucks carry the weight of the locomotive
superstructure and distribute it through the wheels to the rails. Trucks
may be either 4or 6wheel. The latter provides a greater working surface
on the rails and thereby greater tractive effort or pulling power than the
Section II. Preventive Maintenance
A wellplanned and wellexecuted preventive maintenance program
results in greater operational efficiency and increased availability of
railway equipment. Preventive maintenance is an important part of any
overall maintenance program. Not only does it safeguard against emergencies
but also reduces the cost of replacing parts.