(The following article by Tonya Maxwell and Virginia Groark was posted on the Chicago Tribune website on July 14.)
CHICAGO — A lucky electrical-switch malfunction on the last car of a derailed Blue Line train likely prevented more serious damage during Tuesday’s rush hour, officials with the National Transportation Safety Board said Thursday.
The last car of an eight-car train going to O’Hare derailed shortly after 5 p.m. Tuesday, sparking a fire in the subway tunnel just west of the Clark/Lake Station and past the Chicago River.
Investigators had not yet determined what caused the fire, but they said they think a train trip switch, located at the back of each railcar, likely opened during the accident, said Kitty Higgins, a member of the NTSB. The switch is designed to work in conjunction with the signal system and activates the brakes if, for example, a train operator doesn’t heed a red light, they said.
“We believe the derailment essentially tripped the train trip switch. When the car went off the tracks, it hit the ground, the ties, the concrete, something with enough force that it opened this up,” Higgins said, holding the small device.
When the trip switch opened, the electrical current was interrupted and an emergency brake system was automatically triggered, she said.
Higgins said the trip switch is not designed to open in a derailment, and the NTSB’s investigator-in-charge, Mike Flanigon, said he’s never seen a trip switch open in a derailment in his 20-plus years of experience.
It was fortunate that the trip switch opened, they added.
“It very well could have been a worse accident had that not happened,” Flanigon said. “If the train doesn’t stop and the rear car is not on the track and there are seven cars that are on the track with the motors pulling them along, [that could create] more damage and possibly derail the other cars.”
NTSB officials on Thursday said investigators had not determined what caused the train to derail, but they did study the mechanics of the train cars and were satisfied that they functioned properly.
Higgins said the NTSB fire investigator was expected to arrive late Thursday, and she hoped she could determine what sparked the blaze and black smoke that billowed through the tunnel.
No one was killed in the incident, but more than 150 people were taken to area hospitals and treated for smoke inhalation and other injuries. As of Thursday, at least eight people remained hospitalized, one in critical condition, according to hospital officials.
Hundreds of commuters emerged from emergency exits covered in soot after the accident. Many later complained they couldn’t see more than 5 to 10 feet ahead of them as they navigated a narrow catwalk to an emergency exit and never heard instructions about where to go, although the train is equipped with a public address system.
On Thursday, Higgins said that system was working, although the train’s motorman never used it.
She explained a sequence of events that happened in rapid succession:
NTSB officials believe the train derailed and a blue light lit up in the cab, indicating a problem. About the same time, the train stopped, she said, and the motorman realized he had an emergency.
The motorman walked through the first car and stepped onto the tunnel’s catwalk to inspect the train, she said.
“His job is [to] go out and walk the length of the train to determine what’s going on,” Higgins said. “What he realized when he got out there [was] passengers are coming toward him. Then he realized it was his job to get everyone out of there.”
Passengers in the first car had to navigate about 370 feet of darkened walkway–more than the length of a football field–before they found the emergency exit, Higgins said. People in the last car walked about 730 feet, she said.
The train operator stayed on the catwalk helping passengers until the last one left, she said.
Higgins said the emergency lights were working properly and the train controller requested the ventilation system, which potentially could have cleared smoke, be activated. Higgins did not know if that system was working properly.
She added officials will be interviewing a track inspector Friday in addition to examining possible causes of the fire.
The Chicago Transit Authority has turned over its track and train car maintenance records to federal investigators. The NTSB also is reviewing the work history of the motorman, who had been on the job since March 2005. The motorman was on his first run of the day. It was his second day working solo on the Blue Line. Previously, he had worked on the Orange and Green Lines, both of which are elevated routes.
As a combined rail operator, the motorman had to undergo 32 days of general training and then additional rail line-specific training, CTA spokeswoman Noelle Gaffney said.
Within 24 hours of the derailment, three passengers had filed lawsuits. They are all legal assistants of the law firm Corboy & Demetrio, which is representing them.
Attorney Dan Kotin said the fact that his clients work for the firm created no conflict of interest, because the firm would not assign them any work duties related to the Blue Line suit.
“I guess it would make sense that they chose to come to the firm they work for,” Kotin said. “There’s no conflict there.”