WASHINGTON -- Amtrak resumed limited Acela Express runs yesterday for the first time since April, when the high-speed fleet was pulled from service due to cracks in many of the trains' brake rotors.
Amtrak restarted the Acela service with two daily roundtrips, Monday through Friday, between New York and Washington.
The remaining 18 Acela trains will be put back in service once they are equipped with the new brakes, Amtrak spokeswoman Tracy Connell said.
Connell said that Acela service would be eventually restored to Boston, but that only two trains were available for trips yesterday. With limited equipment, Amtrak decided to use those trains on the shorter New York to Washington route in order to squeeze more trips in.
Connell said Amtrak did not publicize the return of the trains beforehand, so many passengers were likely expecting the Metroliner trains that Amtrak has been running in place of Acela.
Montreal-based Bombardier Inc., which makes the Acela trains, said yesterday its target date for equipping the entire Acela fleet with the new brakes is September. Bombardier is still investigating what caused the millimeter-size cracks in 317 of the Acela's 1,440 disc brake rotors. The cracks were found on all 20 Acela trains.
The cracks were noticed April 14, when Federal Railroad Administration Safety Specialist Rich Thomas found them during a routine inspection after a high-speed run to test whether Amtrak could speed up the Acela trains slightly on curves in New Jersey between Trenton and Newark.
Bill Crosbie, Amtrak's senior vice president, said 95 percent of Northeast Corridor passengers continued to use Amtrak trains during the Acela disruption. But the railroad added that its business in the Northeast corridor has fallen by 5 percent since the Acela was taken out of service.
''Acela Express is enormously popular with our passengers, and we're very glad to begin rolling these trains back into service this week," Crosbie said.
Amtrak has been running older and slower trains between Washington and Boston at lower fares to make up for the lost Acela service.
Globe staff writer Keith Reed contributed to this report.