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This paper summarizes the technical development of the low-emission GE-7FDL series locomotive diesel engine. The development focused on reducing the engine exhaust NOx emission significantly while reducing and curbing other visible and nonvisible emissions with minimal adverse impact on the engine fuel efficiency and minimal changes to the engine system and components. Concepts were analyzed, and were investigated using a single-cylinder 7FDL research engine. A low-emission 16-cylinder 7FDL engine and a GE locomotive prototype were built and tested for performance demonstration, function evaluation, and design optimization. The GE low-emission 7FDL engines and locomotives have been in production. The newly developed low-emission locomotive engine meets the EPA Tier-0 levels without fuel efficiency penalty. This was accomplished with minimal changes to the engine system and components. The desired engine reliability performance is retained. The engines are interchangeable with the preceding 7FDL baseline models, and the upgrade of the existing baseline engines to the low-emission version is facilitated.

This paper summarizes the technical development of the GE-7FDL series locomotive diesel engine to EPA Tier 1 emissions standards. The goal of the project was to use the existing GE-7FDL Tier 0 engine with minimal design changes and optimize for performance with respect to the Tier 1 limits. The work focused on statistically quantifying the variation seen under standard test conditions, quantifying the impact of cooling system performance, altitude, and ambient temperature on exhaust emissions and fuel consumption, and developing a robust design and control strategy to ensure optimal emissions and fuel consumption throughout the operating range and life of the locomotive. A Tier 1 prototype locomotive was used during the development to characterize the performance trends of the engine. Testing was performed over the range of altitudes required by the EPA and advanced analysis techniques were used to develop control algorithms that meet Tier 1 emissions requirements and exceed fuel consumption commitments. Extensive verification/validation testing was performed to ensure that the design goals and process capability requirements were met.

The Environmental Protection Agency (EPA) has regulated that locomotives must comply with emissions regulations from sea level up to 2133 meters (7000 feet) altitude. GE Rail has assembled a mobile emissions test laboratory that can be taken by rail to desired testing locations of varying altitude anywhere in North America. This paper gives an overview of the mobile test laboratory’s make up and locomotive preparation for test. Testing was conducted as part of GE Rail’s development of 21st Century Locomotive. The paper presents test results of altitude effects on GE’s Evolution Series Locomotive including regulated emissions and engine performance. The Evolution Series Locomotive meets EPA Tier 2 locomotive emissions regulations applicable to new locomotives manufactured after January 1, 2005.

As with most internal combustion engines, the locomotive diesel is subjected to increasingly stringent regulatory emissions standards. Currently, diesel electric freight locomotives are regulated by the Tier 1 emission standards that went into effect January 1, 2002 as ruled by the United States Environmental Protection Agency (EPA). Beginning January 1, 2005 the US EPA Tier 2 diesel locomotive emissions standards will become effective. To achieve the new emissions standards an extensive engine development program was initiated. This paper will present a portion of the development conducted on a single cylinder engine (SCE) investigating the effects of injection pressure on emissions. The experimental results are presented with a discussion of the possible mechanisms leading to the results with supporting evidence from existing literature and analysis. This paper will focus on the effect of injection pressure as generated by pump capacity and nozzle cup hydraulic flow.