Union Pacific Railroad

Dallas & Houston

Union Pacific Railroad (Union Pacific) has not traditionally been in the business of developing new locomotive designs, relying instead on locomotive manufacturers to design, improve, and build locomotives— as is standard practice in the industry. However, in 2002, the company recognized the need for a new generation of switcher locomotives to reduce diesel-exhaust emissions and improve fuel efficiency. Similar to a tugboat, a switcher locomotive moves rail cars inside freight yards and to-and-from local industries, in contrast with line-haul locomotives, which move trains across the country.

Union Pacific was unable to find a U.S. or Canadian manufacturer willing to produce its prototype low-emitting locomotive. So, in 2004, the company funded the con-struction of its first “Genset” prototype. The Genset locomotive is powered by multiple ultra-low-emissions, off-road diesel engines that are connected to electric generators, thus the name “Generator- Set,” or “Genset” switcher. Instead of using a large conventional locomotive engine that runs continuously at medium speed, the Genset can turn on and off its smaller individual engines to meet horsepower demand. This reduces fuel-use and air emissions. In fact, in comparison with conventional switcher locomotives, Genset locomotives consume 16 to 40 percent less diesel fuel, emit 80 to 90 percent less nitrogen oxides and particulate matter (both factors that may impact air quality), and significantly reduce noise.

Union Pacific’s prototype Genset entered service in December 2005, and was followed by another 164 Genset locomotives: 98 in Dallas–Fort Worth (DFW) and Houston, and 66 in California. It remains the industry’s largest Genset fleet. It’s worth noting that DFW, Houston, and Los Angeles are listed as nonattainment areas for the EPA’s 8-hour ground-level ozone standard. By using less fuel and producing less nitrogen oxides emissions, Union Pacific’s Gensets help reduce precursors to ground-level ozone in these areas.

From initial concept to pilot and implementation, the Genset project challenged 150-year traditions for railroad technology development. It has provided the industry with a new, more environmentally friendly model. Following Union Pacific’s industry-leading development of the Genset, other rail-roads have acquired approximately 160 Genset locomotives. Today, every major U.S. railroad, a major Canadian railroad, several ports and switching companies, and even a locomotive operator in Chile have placed Genset locomotives into service. Without Union Pacific’s leadership and resourcefulness, the Genset locomotive technology that is becoming today’s standard might never have been.