WASHINGTON — Amtrak canceled all of its high-speed Acela Express service in the Northeast again after raising new concerns about a piece of equipment underneath the locomotives, a wire service reported.
The decision was made after a more rigorous inspection of one train that had been cleared to return to service Thursday morning in the Boston-New York-Washington corridor, Amtrak spokesman Bill Schulz said.
“They found cracks that had not been previously detected,” he said.
All 18 Acela Express trains, important moneymakers for Amtrak, were pulled from service Tuesday after inspectors discovered cracks in brackets that attach shock-absorbing “yaw damper assemblies” to the locomotives.
Thursday’s decision represented the second cessation of all Acela trains this week.
Two trains that passed the inspection returned to action Wednesday, and Amtrak had planned to add three more on Thursday. The new problem was discovered on one of those three, Schulz said, prompting the decision to cancel all Acela Express service for the day.
As was the case earlier this week, Amtrak planned to put additional conventional trains into service to fill the gap.
The five Acela Express trains had been due to make a total of 10 departures. Schulz said Amtrak will still make more than 100 departures in the Northeast Corridor.
The new discovery brings to 12 the number of train sets found to have some crack or break in a yaw damper assembly which serves as a sort of shock absorber.
The original problems were discovered around bolts in brackets that hold the yaw dampers in place. In the new case, inspectors removed the skin of the car body and found cracking near the weld of the bracket to the frame.
It also complicates efforts by Amtrak and the train’s manufacturers, Bombardier of North America and France’s Alstom Ltd., to design a temporary fix that will allow all 18 train sets to return to duty.
In a note sent Wednesday to Amtrak workers, Amtrak President David Gunn said the trains could return to service in a few days if a temporary fix gets the approval of railroad and federal government officials.
“But I don’t want to raise expectations here,” Gunn wrote. “The problem is serious and will require a permanent solution. We are not out of the woods by any measure.”
The bullet-nosed trains can travel at speeds up to 150 mph. Until this week, Amtrak typically sent 15 of the trains into duty each day.
Amtrak officials said they feared the yaw damper assemblies could fall off a moving train, damaging its underside or possibly derailing another train. The function of the yaw dampers is to prevent swaying, which can increase wear and tear to rails and train wheels.
Carol Sharpe, a spokeswoman for Bombardier, said the company sent Amtrak 40 replacement brackets that are “sturdier and thicker” than the ones initially installed on the trains. She said testing on the new parts was continuing.
The two trains that returned to service, plus the others that were to have been placed back on the tracks Thursday, were inspected at the end of each trip and showed no signs of problems, Amtrak said.
The first problem was discovered Monday during a periodic maintenance inspection of an Acela Express train in Boston. Amtrak pulled all the trains out of service on Tuesday and filled scheduled gaps with slower trains. About 10,000 people ride Acela Express trains on a typical weekday.