Another possible cause of the fatal crash on the Lowell Commuter Rail Tuesday afternoon comes from the often ignored third paper in Boston, The Metro.
Authorities are also investigating another procedural misstep that may have contributed to the tragedy. Usually when employees are working on tracks they place a piece of metal on the tracks, known as a shunt, that trips a red light signal if a train is headed their way. This gives the train ample time to stop. It appears either the metal was never put in place or the red light signal malfunctioned, said the source.
Investigators are also focusing on a possible dispatcher error
The Herald reports:
Investigators of Tuesday’s fatal Woburn crash believe a railroad dispatcher put the commuter train on a fatal collision course after she heard a maintenance truck call “clear” and mistakenly thought the six man crew had left the restricted work area, said a source briefed on a preliminary federal report.
The “clear” the dispatcher heard was actually a second work crew aboard a high-rail truck, which a short time before had asked train dispatchers for permission to ride down the inbound tracks into the restricted zone where the crew was replacing rail ties, the source said.
Thinking the crew was off the tracks, the dispatcher realigned a switch three miles north of the job site – a switch that had safely moved four trains past the workers – and put the Boston bound train on a 60 mph crash course with the workers, killing two.
coverage from The Globe:
Investigators ruled out mechanical problems yesterday as the cause of the fatal commuter train crash in Woburn and are focusing on how human error put the Boston-bound train on a collision course with a work crew.
“We’re focusing on several aspects of [the] human element, but there are several people that help operate a railroad,” said Ted Turpin, lead investigator for the National Transportation Safety Board. He would not say whether the actions of more than one person were being investigated.