A new type of locomotive may finally open the door to a long-promised network of high-speed rail lines in the United States. Bombardier Transportation (Montreal) recently unveiled a locomotive powered by a jet engine, which replaces the traditional diesel engine found in most current rail equipment.

The JetTrain features a power plant derived from a 5,000-hp Pratt & Whitney PW 150 engine. It is one-tenth the size and 20 percent lighter than a conventional diesel unit, with twice the acceleration. The lighter weight permits high-speed travel without producing damaging track forces.

Historically, only electric locomotives have been able to generate enough power to run consistently at speeds above 110 mph. For instance, the TGV rail system in France uses overhead catenary wires that deliver power as trains speed by at up to 186 mph.

As a result, plans for high-speed rail service in the United States have been limited in many areas where electrification is deemed too expensive to justify the time saved by travelling 150 mph vs. 110 mph. Less than 1 percent of railroad track in North America has electrified overhead wiring, because an electrification infrastructure is expensive to implement and maintain.

Proponents of high-speed rail travel claim that it is an attractive and competitive alternative to both air and automobile travel for trips of 150 to 400 miles. They point to successful systems that operate throughout Europe and Japan. The only high-speed rail corridor in the United States currently operates between Boston, New York City and Washington, DC. Similar corridors have been proposed to link heavily populated areas in the Midwest and West Coast.

"JetTrain technology was designed to offer the speed and acceleration of electric trains without the cost of building electrified rail lines," says Pierre Lortie, president of Bombardier Transportation. "JetTrain high-speed rail is game-changing technology that breaks open the high-speed market throughout North America."

Lortie claims that a train set--seven passenger cars--with one JetTrain locomotive will outperform a train set using two conventional diesel locomotives. He says a conventional diesel-powered train set requires 5 minutes or 6.3 miles to accelerate from a passenger station and reach a speed of 100 mph. By comparison, Lortie boasts that the JetTrain will reach the same speed in only 2.5 minutes or 2.7 miles.

According to Lortie, the new train technology is more environmentally friendly than other forms of mass transportation. "Under operating conditions, JetTrain greenhouse gas emissions will be at least 30 percent lower than from a conventional diesel," claims Lortie. He also says the locomotive is quieter than Federal Railroad Administration noise standards "at all operating speeds."

If the technology is implemented, JetTrain passenger coaches would be equipped with a patented tilting system that allows the train to take curves at higher speeds on existing alignments. "This improves Arial with no compromise in passenger comfort," Lortie points out. He claims that the advanced tilting mechanism reduces centrifugal forces by almost 60 percent.