HORNELL, N.Y. -- The future of American high-speed rail is sitting in a building older than the Battle of Gettysburg: a cavernous factory that holds the first shells of a $2 billion fleet of Amtrak Acela trains due to begin running from Washington, D.C., to Boston two years from now.

Even as Congress moves toward renewed debates over the future of both Amtrak and high-speed rail, the first of 28 new Acela train sets are starting to take shape here. They are the first new generation of passenger trains on the railroad since the Acela's debut in 2000.

For Amtrak, that means a chance to relaunch a service that has been both a commercial success and a procurement headache -- and still the nearest approximation in the U.S. to the high-speed trains that whisk travelers among major cities in Europe and Asia.

Amtrak is buying 28 new sets of power cars and passenger coaches from French manufacturer Alstom SA, which is assembling the trains at its complex of plants in New York's Southern Tier. The train model, known as Avelia Liberty, is from a family of trains already in use in France and Italy, Amtrak executives say.

The new trains will be slowly entering the existing Acela service and will have a top speed of 160 miles an hour, up from 150 miles an hour on the current fleet. The trains will be built to tilt up to 6.3 degrees, allowing trains to run faster in curves and save energy by avoiding braking for some turns.

Average speeds will be much lower, since the Acela will still run on the Northeast Corridor, whose curves will limit trains to top speed in just a few spots. And unlike high-speed trains in Europe and Asia, the Acela shares tracks with commuter trains and freight lines, requiring it to reduce speeds. The new trains will be capable of going up to 186 miles an hour if tracks are later upgraded, Alstom says.

Alstom says the Amtrak contract is helping seed new expertise in their industry.

Mr. MacDonald noted the example of TTA Systems LLC, which has worked with Alstom in Hornell for years. TTA Systems is now building the tilting "bogies" -- the crucial assemblies that connect to train cars and carry their wheels.

"They've overhauled 30-year-old bogies for years that are on a metro car that's going 30 miles an hour," Mr. MacDonald said. "This is going to 170 miles an hour, and it's going to tilt. It's a different animal."

On Amtrak’s forty-mile run between Washington, D.C., and Baltimore, for example, trains run as fast as 125 mph on some segments. But because all trains on the line must spend a long time creeping through the yard at Washington’s Union Station and through antiquated tunnels under Baltimore Harbor, the average speed of even the fastest scheduled train, the vaunted Acela, is only 83.4 mph. Increasing speeds on the slowest segments of the line would do as much or more to shorten travel times as making the fastest speeds faster, and wouldn’t require an expensive new right-of-way or new equipment.

The top speed obtained by any train is 150 mph, and that happens only in a brief segment of Rhode Island. The average speed is much lower, even to the point that the schedule today between New York and Boston is only nineteen minutes faster than that achieved by the New Haven Railroad’s “Merchants Limited” in 1954