Building on its reputation as having the most environmentally friendly locomotive fleet in the United States, Union Pacific today announced it is testing technologies to reduce diesel engine emissions in older railroad locomotives.

Through collaboration with staff at the National Vehicle and Fuel Emissions Laboratory of the U.S. Environmental Protection Agency (EPA) from Ann Arbor, Mich., Union Pacific is providing a 3,800-horsepower SD60M locomotive built in January 1992, to serve as the first freight locomotive in North America to be equipped with a set of oxidation catalyst or "oxicat" devices manufactured by the MIRATECH Corporation of Tulsa, Okla. These devices serve as flow-through catalytic converters. As the diesel engine's exhaust flows through these converters, microscopic particles -- known as "particulate matter" -- generated by the diesel combustion process will be converted into water and carbon dioxide.

In a similar experiment, a 1,500-horsepower yard switching locomotive built in November 1982, also provided by Union Pacific, will be retrofitted with a diesel particulate filter or "DPF." The DPF initiative is the result of a four-year program, funded in part by Union Pacific, to assess clean-engine technologies for locomotive applications. The DPF acts as a filter that uses high-temperature silicon carbide blocks to trap particulate matter in the exhaust. As the gases containing the carbon particles accumulate, the device periodically heats the carbon causing it to ignite and burn off as water and carbon dioxide.

"Over the last few years, Union Pacific has improved fuel efficiency 14 percent through operational changes and by acquiring newer, more efficient locomotives," said Bob Grimaila, Union Pacific's vice president for environment and safety. "We are now researching technologies to reduce diesel engine emissions, especially particulate matter, from older railroad locomotives. This supports our goal to reduce fuel consumption and diesel engine exhaust-related emissions. In turn, this helps to create a better environment and cleaner air to breathe."

The Southwest Research Institute (SWRI), a renowned applied research and development organization based in San Antonio, is handling the modification of the SDM60 locomotive and installation of the oxicat device. Upon installation, SWRI will perform EPA locomotive emissions tests -- similar to the emissions test performed on automobiles -- to verify how much particulate matter is removed from the locomotive's exhaust. Afterward, Union Pacific will relocate the locomotive to the Los Angeles Basin for at least one year of regular service with the new catalytic converter to test real-life conditions operating in over-the-road freight service.

The DPF-equipped yard switching locomotive will be returned to service in Oakland, Calif., in September.