Cracks Cause Amtrak to Halt High-Speed Northeast Trains
Amtrak found the cracks during a regularly scheduled inspection in Boston on Monday afternoon and immediately ordered the trains slowed to 80 miles an hour. It also ordered inspections of all the other trains. When more problems were found on Monday night, Amtrak pulled the Acela Express from service.

Experts say a train could shed big chunks of metal while traveling faster than 100 miles an hour, damaging the train or other trains with the cracked part. Federal Railroad Administration officials praised Amtrak for acting promptly.

Railroad experts said that newly designed trains sometimes showed structural problems after a few months of use. A railroad executive with 30 years of experience in safety at a freight railroad said that locomotive design was relatively unsophisticated.

"We don't have computer models that are highly accurate, like they do in aviation, in the relationship between the power car and the track structure," said the executive, who spoke on the condition that he not be named. Such structural problems can be fixed, he said, adding that a number of railroads, including the Long Island Rail Road, have described problems around the area of the part that now ails the Acela, called a yaw damper.

The yaw damper is supposed to control a problem in which the train wheels tend to point from side to side, causing excessive wear. The Acela had such a problem when it was first tested, but engineers believe that they have solved it.

The Acela Express was built by Bombardier of Montreal and Alstom of Paris, which have extensive experience in European train design. One problem, though, is that high-speed European trains are not crash-resistant enough to meet American regulations, so some redesign is required. The tracks themselves cannot handle the speeds that have kept European trains as competitive alternatives to flying for trips of a few hundred miles. Improving the tracks would take billions of dollars, akin to the amounts spent on highways, and rail advocates point out that Congress has not even provided enough money to maintain current service.
http://www.nytimes.com/2002/08/14/national/14TRAI.html