Creating a Green Locomotive

A Union Pacific Employee’s Vision Transforms the Way Locomotives are Powered

Editor's note – Since this story was written, Union Pacific introduced four "next generation" Genset switcher locomotives at its Roseville, Calif., rail yard in May 2008. These diesel locomotives are used in the rail yard to push rail cars over an incline, or hump, where gravity then propels the cars to destination-specific tracks. The new Gensets provide increased power with six traction motors, while maintaining the environmentally friendly standards of the previous four-traction motor models. Also, there has been an update to the emission and fuel saving data – The Genset switcher reduces emissions of nitrous oxides by 80 percent and particulate matter by 90 percent.

Omaha, Neb., May 22, 2007 – From its very beginnings, the key to a locomotive's power has been its ability to convert fuel into motion. During the 19th and early 20th centuries, locomotives harnessed steam to move trains. Almost anything that would burn was used to fuel a fire under a water-filled boiler that created the steam.

In the early 1930s, electricity began replacing steam. Locomotives became electric power generators producing electricity to drive motors attached to axles and wheels. Diesel became the fuel of choice to power the on-board engine that helped generate the electricity.

In 2002, Union Pacific's Mike Iden, general director of car and locomotive engineering, thought it was time to take locomotive technology to the next level. Since many locomotives do not require maximum horsepower (1,200- to 2,100-horsepower for switch or yard locomotives and 4,000-to-6,000-horsepower for long-haul road locomotives) all the time, Iden investigated the development of a switching locomotive that would use modern off-road diesel engines. Modern off-road diesel engines would be capable of providing the lower power required by typical switching locomotives while reducing fuel consumption and, most importantly, exhaust emissions. Instead of having one large conventional locomotive diesel engine operating at various speeds, only one of which was most fuel efficient, why not use multiple smaller diesel engines, running in combinations of 1, 2 or 3 engines, to produce the required horsepower levels?

"My vision was to package the diesel engine, electrical generator and even the cooling system radiator in one compact, easily replaced module called a generator set or 'genset,'" Iden said.

He began work to find out if several gensets could be assembled together on one locomotive platform to produce the same power as one older conventional diesel locomotive engine. Mass-produced locomotives with multiple diesel engines had previously been manufactured in the United States, but never using the design concept of multiple, modular, easily replaceable gensets. The only exception was an experimental high-speed passenger locomotive built with modular diesel-generator sets in 1941; it was never sold nor were any other such locomotives built.

Iden started discussions about genset switchers with a small Illinois-based locomotive remanufacturing company, National Railway Equipment, and spent more than a year refining the concept and making preliminary plans for a prototype called the "Genset switcher."

In 2004, Union Pacific authorized construction of a prototype low-emission Genset locomotive. No manufacturer offered such a locomotive, and many doubted the feasibility or need for such a switching locomotive.

Undaunted, Iden moved forward and a prototype 1400-horsepower Genset was built for UP during 2005 and tested in Illinois and California. The prototype is powered by two generator sets, each with a 700-horsepower, ultra low-emissions off-road Cummins diesel engine that reduce nitrous oxide and particulate emissions by up to 80-90 percent, while using as much as 16 percent less fuel compared to other low-horsepower locomotives. The 16 percent less diesel fuel usage also translates into a minimum 16 percent reduction in greenhouse gases.

The entire Genset locomotive and each of its two generator sets are computer controlled. One generator set is initially used when starting the locomotive. As the locomotive engineer goes to increasingly higher throttle settings, the second genset engine is quickly started and begins providing power. When that power demand is no longer needed, the second unit automatically shuts down. The prototype Genset locomotive also was equipped with Automatic Engine Stop Start (AESS) technology that shuts down the locomotive when it is not in use. Most importantly, emissions tests on the prototype found that the 80-90 percent reduction in exhaust emissions was practical and could be achieved.

Though still being evaluated in early 2006, the prototype Genset locomotive worked well enough for UP to move beyond the prototype stage.

In February 2006, Union Pacific expanded its use of Genset technology by ordering 60 bigger-and-more powerful production versions from National Railway Equipment – all for use in UP's Los Angeles Basin rail yards. Each new Genset locomotive is powered by three 700-horsepower ultra low-emissions U. S. Environmental Protection Agency (EPA) non-road Tier 3-certified 6-cylinder Cummins diesel engines. All 60 of the Gensets bound for Los Angeles are expected to be delivered and working by July 2007.

Also in early 2006, Union Pacific ordered 98 2,000-horsepower Genset switching locomotives from Railpower Technologies. Each is powered by three generator sets with EPA Tier 3-certified 8-cylinder Deutz diesel engines. All 98 are being assigned to Union Pacific rail yards in Texas.

Genset locomotives are just one of the technologies Union Pacific is pioneering to help reduce locomotive emissions. By the end of 2007 Union Pacific will have invested more than $5 billion to purchase new, environmentally friendly locomotives, and will have invested millions of dollars to test technologies that reduce emissions from older locomotives.

For further information, contact Mark Davis at (402) 203-0964, James Barnes at (402) 544-3560 or Gene Hinkle at (402) 514-9406.

The statements and information contained in the news releases provided by Union Pacific speak only as of the date issued. Such information by its nature may become outdated, and investors should not assume that the statements and information contained in Union Pacific's news releases remain current after the date issued. Union Pacific makes no commitment, and disclaims any duty, to update any of this information.