Southwest Research Institute (SwRI) engineers say they have reduced nitrogen oxide (NO(sub x)) emissions on a 4,200-hp, 16-cylinder, natural-gas-fueled (LNG) engine by 75% when compared to a diesel-fueled counterpart. "These emission levels make using LNG an attractive proposition for rail companies in noncompliance areas, such as Southern California and parts of the Northeast, where diesel locomotives contribute substantially to air pollution," David Meyers, a group leader in SwRI's Engine and Vehicle Research Div., reported to members of the GasRail USA industry research project. GasRail was initiated in 1993 by SwRI, together with federal, state, and industrial participants, to demonstrate that LNG could contribute to lower NO(sub x) emissions. To date, SwRI has designed, tested, and evaluated six LNG engine combustion systems. The locomotive system selected, known as LaChip (Late cycle High Injection Pressure), uses small amounts of diesel fuel as an ignition source for the high-pressure natural gas injected late in the combustion cycle. Diesel fuel also can be used in an emergency, allowing the locomotive to pull into a shop for repairs if the LNG supply is interrupted. The system will be field-tested in a Metrolink commuter locomotive owned by the Southern California Regional Rail Authority in early 1999. FAX Elizabeth Douglas at (210) 522-3547.