(The following article by Patrick McGeehan was posted on the New York Times website on June 3.)
NEW YORK — A week after a major power failure shut down most of its train service in the Northeast, Amtrak suffered another electrical problem just as the weekend getaway rush was starting yesterday.
At 3:30 p.m., the loss of one of Amtrak’s main sources of power in the region slowed trains running between New York City and Philadelphia. As a precaution against having trains stalling in the tunnel under the Hudson River, as three did last week, Amtrak barred trains from entering it for about 45 minutes, said Clifford Black, an Amtrak spokesman in Washington.
Mr. Black said a power disruption near Philadelphia, possibly the result of a lightning strike, caused yesterday’s shutdown. He said the problem was not related to last week’s widespread electrical failure, which Amtrak has not been able to explain.
But a Pennsylvania utility disputed Mr. Black’s explanation, saying that its power supply to Amtrak dropped briefly but never shut down. A utility spokesman said that Amtrak’s problem might have been a result of breakdown in its own electrical system.
Amtrak also briefly halted all New Jersey Transit trains on three lines that use Amtrak’s tracks to Pennsylvania Station in Manhattan. Dan Stessel, a spokesman for New Jersey Transit in Newark, described that shutdown as “an effort to ensure that trains would not become stranded in the event of a repeat of last week.”
Mr. Black said that full power was restored by 4:16 p.m. and trains began running as normal. But service on Amtrak and New Jersey Transit was delayed as the evening rush began.
At 4:30 p.m., Mr. Stessel reported that some New Jersey Transit trains were running about 30 minutes behind schedule. An hour later, he said the delays had cleared.
Mr. Black said the “diminution of power” was unrelated to the electrical failure on May 25 that ruined the morning trip to work for tens of thousands of commuters and left hundreds of them stranded in the Hudson tunnel for more than two hours. Amtrak is still investigating that unprecedented failure, which cascaded from one substation to another between Maryland and Queens, he said.
“It appears that it’s unrelated because it was very clear what the problem was,” Mr. Black said.
He said a cable near Philadelphia that belongs to PECO, the primary supplier of electricity in southeastern Pennsylvania, stopped feeding current to the overhead lines that power the trains. Supplemental power was provided by other substations along the line, but not enough to keep the trains running at full speed, he said.
But a PECO spokesman, Michael Wood, disputed that account. He said that both of PECO’s 69,000-volt supply lines had remained in service throughout the day and that the company’s transmission system had experienced only a brief drop in voltage that it attributed to a lightning strike.
Mr. Wood said that Amtrak’s equipment that converts the frequency of the current delivered by PECO “shut down when it sensed the drop in voltage.” But it should not have and has not done so in the past, he said.
“We did not lose any other equipment on the PECO system,” Mr. Wood said.