Evaluation of Locomotive Emissions Reduction Strategies

North Carolina Department of Transportation (NCDOT) owns diesel locomotives operated by Amtrak for service between Raleigh and Charlotte. The Rail Division seeks to quantify the emissions of these locomotives and to identify and evaluate options for reducing their emissions. Such options include rebuilding of the diesel prime mover engines (PMEs), replacement of head end power (HEP) engines, use of biofuels and compressed natural gas (CNG), retrofitting emission controls, and evaluation of operational practices that may lead to lower emissions. NCDOT has six locomotives with EMD12-710 3,000 hp PMEs and with CAT ACERT C18 900 HP HEP engines. The EMD12-710 engines have been rebuilt and are subject to Environmental Protection Agency (EPA) Tier 0+ emission limits. The C18 engines were certified to EPA’s nonroad engine Tier 2 standard. NCDOT is acquiring two additional locomotives with EMD12-710 engines, which are to be rebuilt, and will replace the HEPs with CAT ACERT C15 engines certified either to Tier 3. NCDOT is planning to include PME exhaust after-treatment systems (EATS) for recently acquired locomotives, and to retrofit EATS to the existing six locomotives. These aftertreatment systems should bring the overall locomotive emission levels to at or very near Tier 4. NCDOT is interested in the potential for biodiesel fuel to further reduce emissions. NCDOT is also evaluating conversion of recently acquired locomotives to a dual-fuel capability with diesel and CNG. They have observed variation in locomotive engineer behavior that may lead to variability in emissions. The effect of such behavior is unknown. The key objectives are: (a) to assess baseline fuel use and emission rates (FUER) for PME and HEP engines for ultra low sulfur diesel (ULSD) fuel; (b) to assess FUER for the newer C15 versus older C18 HEPs to evaluate the effectiveness of Tier 3 (or higher) versus Tier 2 nonroad emission standards; (c) to assess the operational impact of EATS on FUER; (d) to assess the effect of biofuel, and possibly also CNG (depending on availability), on FUER of the newly acquired locomotives; (e) to assess inter-run variability in duty cycles with regard to impact on FUER; and (f) to assess the joint and interactive effect of operational practices, fuels, and EATS on FUER. The key tasks to support these objectives include: (1) development of a detailed study design and preparation for measurements; (2) rail yard (RY) measurements of PMEs and HEPs; (3) over-the-rail (OTR) measurements of PMEs; (4) quantification of the effect of engine technology and EATS on FUER; (5) quantification of the effect of operations; (6) quantification of the effect of fuels; and (7) evaluation of the interactive effect of fuel and emission management strategies and their implications. Key products of this research will include new data on real-world activity, energy use, and emissions of locomotives and new insights regarding the actual real-world implications of technology, fuels, and operational practices. The specific products of this work will include new measurements of fuel use and emission rates in the railyard and over-the-rail. The NCDOT Rail Division will use the results from this study to make decisions regarding adoption of fuels (e.g., biofuels, CNG) and EATS and to develop guidance for locomotive operators regarding best practices for managing fuel use and emissions. Furthermore, data such as these are critical to NCDOT’s applications for Federal funding for rail improvement projects, for which NCDOT must demonstrate improvement in air quality as a key requirement. The results of this research will enable NCDOT Rail Division management to make informed decisions regarding acquisition of capital assets and fuels that can reduce energy use and emissions of the growing fleet of railroad locomotives. Furthermore, the results of this work will enable NCDOT to collaborate with Amtrak to identify potential improvements in operational practices that may lead to reductions in real-world fuel use and emission rates. The data and insights from this project are also critical to the Rail Division’s applications for Federal funding for rail improvement projects, for which a commitment to improving air quality is a key requirement. Furthermore, NCDOT and Amtrak can attract a growing customer base by marketing a greener approach to operations.


    • English


    • Status: Completed
    • Funding: $199644
    • Contract Numbers:


    • Sponsor Organizations:

      North Carolina Department of Transportation

      Research and Development
      1549 Mail Service Center
      Raleigh, NC  United States  27699-1549
    • Project Managers:

      Kirby, John

    • Performing Organizations:

      North Carolina State University, Raleigh

      Department of Civil Engineering, Campus Box 7908
      Raleigh, NC  United States  27695-7908

      University of Washington, Seattle

      Washington State Transportation Center
      1107 NE 45th Street
      Seattle, WA  United States  98105
    • Principal Investigators:

      Frey, H

    • Start Date: 20150816
    • Expected Completion Date: 20170815
    • Actual Completion Date: 20171231

    Subject/Index Terms

    Filing Info

    • Accession Number: 01573245
    • Record Type: Research project
    • Source Agency: North Carolina Department of Transportation
    • Contract Numbers: FHWA/NC/2016-20
    • Files: RiP, STATEDOT
    • Created Date: Aug 18 2015 2:10PM