Hydrogen is routinely dismissed as a ”decades away” fuel technology for vehicle propulsion. But while much attention has been focused on fuel-cell-powered passenger cars, a little-noticed but promising development has been taking place in rail transportation and heavy industry, where experiments with hydrogen-fuel-cell propulsion are well under way.

Among the objectives: running equipment that operates indoors or underground on fuel cells rather than on batteries; powering small rail ­systems at mines, factories, and military bases; and replacing diesel-electric locomotives on suburban lines with fuel-cell-driven electric motors. One company at the forefront of these developments is Vehicle Projects LLC, in Denver.

In one job, Vehicle Projects is retrofitting a 109-metric-ton diesel-electric yard-switcher locomotive with a power train that features polymer electrolyte membrane, or PEM, hydrogen-fuel-cell stacks [see photograph, ” ”]. The cells, made by Nuvera Fuel Cells Inc., of Cambridge, Mass., combine hydrogen and oxygen in a chemical reaction that yields heat, water, and electricity to power a 1.2â¿¿megawatt locomotive. It was commissioned jointly by the U.S. Department of Defense, the U.S. Department of Energy, the government of Japan, and the National Automotive Center, in Warren, Mich. The seven-year project began in 2003.

”The army is interested in fuel-cell locomotives because they can serve as mobile backup power supplies for military bases,” says Arnold R. Miller, president of Vehicle Projects. ”If you have this fuel-cell locomotive, rated for 1.2 megawatts,” he said, ”it will serve its primary role as a switch engine in military rail yards. But in the event of an attack on a base, a failure of the grid, or some natural disaster such as Hurricane Katrina, you could drive it to wherever you need it, hook it up, and provide enough power for about 1000 homes or to keep people who are dependent on respirators or dialysis machines alive.”

Vehicle Projects, spun out of the Colorado School of Mines, in Golden, is recognized as the first company to have built a fuel-cell locomotive. Its earlier 3.6-metric-ton, 17-kilowatt hydrogen-powered mine locomotive—for which Nuvera also supplied PEM fuel cell stacks—was completed in 2002 and demonstrated in a working mine in Ontario [see photo, ” ”]. ”We retrofitted a battery-powered locomotive, because it already had an electric drive,” says Miller.

Miller says that the mine locomotive served as a proof of concept for all that needs to be verified in a fuel-cell vehicle. Is it safe? Can you easily and regularly refuel the vehicle? Does it deliver enough power for industrial, commercial, and commuter applications? Compared with the battery-powered locomotive it replaced, he says, ”it had twice the power and could be refueled with hydrogen in 30 to 45 minutes, as opposed to 8 hours.”

Vehicle Projects is also playing a role in the race to build the first commuter fuel-cell locomotive. It has supplied a 150-kW fuel-cell power plant, consisting of eight fuel-cell stacks and ancillary equipment like a water pump and an air compressor, to Tokyo’s Railway Technical Research Institute (RTRI). The institute is battling Japan Rail East for the honor of running the first fuel-cell locomotive on a passenger line. The winner is likely to come forward in the next year or two.

RTRI is planning a two-car locomotive—one carrying electric motors, a transformer, and a battery charged by regenerative braking, and the other holding fuel-cell stacks and a hydrogen storage cylinder. The train’s top speed will be 120 kilometers per hour, and it will travel 300 to 400 km before its hydrogen needs replenishing. Officials say they hope to have the train ready by 2010, and a prototype, with one-fourth the propulsion power of the proposed final version, is already being tested.