The layout of train tracks and signals in the vicinity of today's Chase train wreck is a standard one throughout the industry and required no changes in the wake of a fatal passenger train crash near that same spot in 1987, a federal safety official said.
"That is not a complicated arrangement," said Edward R. English, director of the Office of Safety Enforcement with the Federal Railroad Administration. "That is a fairly normal, standard arrangement within the industry."
Meanwhile, Amtrak spokesman John Jacobsen said that there was nothing to indicate that today's accident at the site of the 1987 crash was "anything other than an unfortunate coincidence. But coincidences do happen."
He said there is "nothing unusual or inherently dangerous" about the track and signal arrangement in the area of the crash.
"This is a whole area that was redesigned and improved" in the early 1970s, he said. "I have heard no one . . . suggest that we have a problem with the basic track design."
The layout in that vicinity narrows from four tracks several miles south of the Gunpowder River bridge to three tracks and then two tracks going over the bridge, including several signals and switch-overs before the bridge.
"You can see this uniformly anywhere in the country when you're looking to cross trains from one track to another," said English of the number of "interlocks" or switch-overs.
Amtrak and federal safety officials have stressed that human factors, including drug use, played a major role in the 1987 crash.
"There were no physical changes ordered as far as the track layout, signal placement in Chase, Maryland," said English. "The physical layout of the track and signals really had no bearing on the first accident."
A spokesman for the National Transportation Safety Board, meanwhile, said that "all the equipment worked fine" in 1987's fatal crash. "The signal checked out. There was a guy on drugs who didn't pay attention to the signal. . . . There's no reason to change the signals in a case like that."
In the wake of that first crash, however, federal authorities did order several other safety changes, including:
* Pre-employment and random drug testing for all operating train crews.
* Cab signals on all locomotives operating along the Northeast corridor, a system that gives a constant display inside the train cab itself of the safety signals that appear along the wayside.
Those signals already were required in passenger trains and were installed in all freight trains along the corridor as of last year.
* A mechanical system on board every train, requiring that engineers acknowledge and respond to the changes in safety signals. Failure to do so results in the train being stopped automatically.
* Lower speeds along that corridor during peak passenger hours.
The inquiry into today's crash will consider the possibility of both human and mechanical errors, mainly involving the northbound train, the Amtrak spokesman said.
Jacobsen said investigators will look at whether the signaling system was working properly and whether signals worked inside the locomotive's cab.
They also will examine what steps the northbound engineer took in response to any warning signals, including the speed of the locomotive and when the brake was applied. They will examine the locomotive's brakes and the track itself.
If everything had worked normally, said Jacobsen, the northbound train would have received a signal warning it that a southbound train was crossing the tracks at some point ahead of it and would have responded accordingly.