Hybrid automobiles, which run on conventional fuel and electric battery power, are becoming more common on American highways. Now, the U.S. railroad industry is looking at the same environmentally-friendly technology. The nation's biggest railroad is testing a one-of-a-kind hybrid-powered locomotive at a railyard in Roseville, California.

It's called the Green Goat, and it's in service at Union Pacific's sprawling switchyard hub in Roseville.

Switcher locomotives, which are used to assemble trains, are known in the railyards as 'goats'? and this one's 'green' because it's environmentally friendly. Today, it's at work adding cars to what will eventually be a 90 car freight train.

The quiet sound of the Green Goat when it's moving is one indication that it's a hybrid. It runs on battery power, with a small diesel engine charging the batteries.

"I guess the last nine months we've been more or less working the bugs out of it," says California native Frank Donnelly, the man who developed the technology and is overseeing testing of the Green Goat in Roseville. He says it's right on track. "This is not pie in the sky [fantasy]. We have a locomotive that's operating here that's doing the job of a conventional locomotive and the benefits are very demonstrable. It's cheaper to operate and has fewer emissions."

The Green Goat looks a little different than the other locomotives in the yard. It's shorter in front and its long rear hood is much lower because a bank of batteries has replaced the huge diesel engine. Mr. Donnelly opens a hatch on the hood to peer inside.

Donnely: "Each one of these batteries is about 1,500 amp per hours and there's a total of 1,500 cells."
Barr: "Now these are a lot bigger than car batteries"
Donnely: "A lot bigger, but it's the same technology." The railroad industry has relied on diesel locomotives for the better part of a century. Many have been in service for 30 years or more. But locomotives are increasingly recognized as a significant source of pollution? according to Tim Taylor, with the Sacramento Metropolitan Air Quality Management District. "Locomotives represent something on the order of one-tenth of the nox, that is, oxides of nitrogen emissions, that go into the air here in the Sacramento region. Nox is a major contributor to ozone formation. If you breathe too much ozone it can cause all kinds of respiratory problems," he says.

Mr. Taylor says regional air quality officials are now just beginning to work with railroads, like Union Pacific, to reduce locomotive emissions. "We don't have any regulatory authority to do that and we're only exploring the potential," he says.

The first-ever national regulations on locomotive emissions were implemented two years ago. Now, fear of future regulation is forcing an industry that's deeply rooted in the past to look to the future. Union Pacific spokesman Mike Iden says the Green Goat is just one possibility. "We want to know, first of all, what technology alternatives are out there and start to get a handle on their feasibility."

Back in the cab of the Green Goat, Frank Donnelly looks on with pride as the engineer puts the locomotive through its paces. "Engineers love it. It's quiet, it has instant power and it's air conditioned," he says.

There's a lot riding on the Green Goat. Mr. Donnelly's Canadian-based company, Railpower Technology, has invested more than a million dollars in the locomotive. Once the testing phase is complete, he hopes Union Pacific will be impressed enough to buy a fleet of Green Goats. That could lead the industry to move toward the use of even more environmentally friendly technology on America's railways.