In selecting lubricants, the rules and approvals of the respective engine manufacturers should be observed, above all for the engine oil. The diesel engines may range from four-cylinder in-line engines in smaller models to heavy goods and express train locomotives with 16-cylinder V engines. The power produced by the engine is transmitted hydraulically or electrically to the wheel sets. Gears in turn sit on the wheel sets, which must be supplied with gear oils. Nor should we forget radiator antifreeze or greases for the bearings or the wheel flange lubrication. Depending on the operator of the locomotive, it is not always the approval of the component manufacturer or recommendations by Vossloh which is decisive for the choice of lubricant, but also that of the railway company. For example, at its competence centre, Deutsche Bahn AG classifies lubricants into three grades, Q1 to Q3. Q1 stands for the highest quality grade. An approval or listing in the maintenance documents of Deutsche Bahn AG Systemtechnik is regarded as a practice-oriented guideline. It is also used as a guideline by many other railway companies.
Hence, not only the choice of lubricant plays an important role but also its monitoring in practice. In order, e.g. to check the perfect condition of the oil and of the engine, the technicians of Vossloh Locomotives use OELCHECK lubricant analyses. In each case, after 500 hours of operation, a used oil sample from the engine is investigated. The oil analysis is thus a fixed component of engine maintenance. In addition, gear oils and other lubricants are analysed to clarify causes of damage.
Vossloh locomotives are well-known for their efficiency and reliability. Lastly, they must perform their service in wind and bad weather and sometimes under the most extreme operating conditions. Even at temperatures as low as -40°C during the icy Norwegian winter, there can be no malfunctions. If there are no third party supplies of thermal heat available at such low temperatures during stoppages or even for the whole night, the locomotive engines continue running while stationary. In this way, at least the cooling water of the locomotive warms the carriages. This can nevertheless cause problems in many types of engine, since this measure prevents the cooling of the train. But with incomplete combustion of the diesel fuel under no-load running operation of the cooled engine, unburnt diesel and condensate can get into the engine oil. For regular driving with engine oil temperatures of over 60°C, water and fuel begin to evaporate and vaporise. There is nevertheless a residual risk to the engine, which may only be excluded through regular oil analyses with the precise determination of the water and fuel content of the oil.
In addition to the problems arising from water and diesel condensates, at low temperatures, oil and fuel vapour from the crankcase breather may collect in the loading air shaft. If power is then connected, these vapours can cause the engine to self-accelerate in uncontrolled fashion and thus „run away“. Not least, by virtue of the oil analyses, Vossloh Locomotives has also developed solutions for such low-temperature problems: for example, for the DE 2700, an electric preheating system is built into the engine as a standard feature. In addition, as a prudent measure, more and more locomotives are equipped with an auxiliary diesel engine. Beside the preheating of the cooling water and the fuel, it at the same time guarantees the trickle charging of the on-board batteries. Correspondingly equipped and monitored by OELCHECK with regular lubricant analyses, the locomotives from Kiel always reach their destinations safely, wherever they may be and even at the lowest temperatures.