Introduction of Bus Diesel Engine Emission Control and Fuel Technologies to the Locomotive Industry

The diesel locomotive is going through a metamorphosis of sorts as the Environmental Protection Agency (EPA) has enacted emission standards which dictate reduced diesel exhaust emissions for newly manufactured and remanufactured locomotives and locomotive diesel engines. While the implementation of the emission standard tiers is cause for industry concern, it is not cause for panic. While many can make assumptions concerning resulting engine reliability, performance and fuel economy, one only has to look to the bus industry to learn that a very similar program was initiated in that industry well over a decade ago. Sure a bus engine is not a prime mover but the very technologies that are being both considered and rejected for locomotive engines have already been in revenue service on buses since 1991. This paper makes two major points, the first is that the bus industry has successfully responded to a similar diesel engine emission and diesel fuel clean up (which continues to this day and on into calendar year 2010) and has embraced new technologies that have met and/or exceeded the emission requirements without experiencing drastic impacts to operating costs. The second point to be made is a little more scientific but it surfaced as one of the major concerns resulting from the reduction in sulfur content in diesel fuel. Sulfur reduction apparently created a more enhanced environment where microorganisms can thrive resulting in diesel fuel storage contamination, fuel filter plugging and fuel injector nozzle clogging. The emission regulations promulgated affected both new and rebuilt engines and also embraced the concept of an emission controls system whereby the engine had to work in concert with the diesel fuel and the diesel fuel regulations had to be maintained with no relief so that the engine manufacturers could “count on” diesel fuel standards that would assist their emission control efforts. The major transit properties across the nation embraced low sulfur diesel fuel and ultra low sulfur diesel fuel years before it was required by the EPA. This permitted more advanced emission control technologies to be investigated giving the operators an opportunity to familiarize themselves with the proposed technologies and their associated cost of implementation and operation. To date, the emission levels of bus diesel engines are significantly reduced and will continue to decline while tens of thousands of buses on the road today continue to operate reliably providing revenue service for the hundreds of thousands of daily passengers all across the nation. If any of this is sounding familiar it should, a very similar program has now been laid out for diesel locomotives and so it is proposed that one consider taking advantage of the lessons learned in the bus industry concerning emission reduction technology and diesel fuel storage and applying them to diesel locomotive operations.