Many of us will find ourselves with challenges in maintaining vehicles that comply with the increased demand for lower emissions. Those challenges are both technical and financial, especially when considering diesel-electric hybrid buses at Euro VI.
Duty cycles have a highly significant impact on these challenges. For instance, in the slow, stop-start London traffic that I am most familiar with, hybrid buses perform very well. But when I talk to colleagues outside London, their experience is often very different. In contrast to that, diesel Euro VI exhaust aftertreatment systems certainly favour the higher average speeds and higher exhaust temperatures found outside the capital.
Specialist skills now required
For several years now, maintenance requirements have become more demanding and the number of complex systems that require specialist skill and knowledge to perform effective diagnosis and repair have been increasing. It is great to see that the IRTE Skills Challenge has evolved to recognise that, and now has categories for areas such as Best Electric Driveline Technician.
As a large, multi-fleet operator, choosing the right diagnostic equipment is a challenge. Generic diagnostic tools are great for most needs, but you invariably still need the OEM diagnostic equipment to carry out certain tasks. There are usually stringent training and licencing controls around the use of these in place.
Fluid analysis proves useful
Another characteristic of modern vehicles are high specification fluids. We now carry out routine fluid analysis, which enables us to assess the condition of the fluid and ensure that we are maximising the useful life of it.
The other significant benefit of fluid analysis is to gain insight into the characteristics of the foreign components present within the fluid. We can often see issues develop before any symptoms are present. That allows early intervention, which can prolong the life of the component and reduce the cost of repair. This has required us to develop a detailed understanding of how to interpret the analysis reports to make use of the information that they provide.
As we move to zero-emission buses, many of the challenges presented above change. I do not have adequate exposure to or experience of what the implications are for maintenance and repair of a hydrogen fuel cell-electric bus. However, for battery-electric buses, the maintenance demands are proving to be lower in most areas.
Issues caused by vibration, diesel systems, exhaust aftertreatment units and high temperatures are all eliminated. The body issues are relatively unchanged, and with substantial regeneration, the brakes are not doing as much work as they used to. Increased vehicle mass does mean that the suspension requires more attention, though.
Fresh look at inspection intervals for ZE?
Focus now shifts to ensuring that the vehicle systems remain as energy efficient as they can be, as problems here are most likely to cause disruption with daily operation. Something that perhaps requires further work is a consideration of vehicle inspection frequency. There are fewer opportunities on an electric bus to encounter safety-related defects, so is it appropriate to consider a longer safety inspection interval?
