By Anna Lothson
The National Transportation Safety Board, the federal agency tasked with investigating Monday morning's Blue Line crash at the Harlem stop, released a report Oct. 4 detailing its "urgent" recommendations for the Chicago Transit Authority.
The Sept. 30, incident involved a driverless four-car CTA train that traveled along a half-mile track in the wrong direction until it struck a stationary train at 20 miles per hour, leaving dozens of people injured.
Friday's NTSB report revealed that the unoccupied train was left running while it was awaiting repairs when it began moving, traveling through five mechanical train stop mechanisms. The emergency brakes were applied, according to the report, and it was momentarily stopped several times before it reached the Harlem station, where the crash occurred.
"Following each stop, the train movement returned because the master lever on the operator console had been left in a setting that allowed the train car brakes to recover and reset from the emergency brake application. …the investigation of the cause of unintended movement continues."
According to the report, it's not uncommon for unoccupied CTA trains to be routinely left powered-up while stored in a manner that would allow movement. The NTSB, however, suggested that there are safety mechanisms available for the CTA to use to prevent such an issue from occurring again.
"The NTSB believed that had a wheel chock and/or a derail been in use at the Forest Park Terminal, the train could have been stopped before it entered mainline track and the accident could have been prevented."
"Chocks" are placed on the rail immediately in front of a wheel to prevent the wheel from rolling in the direction of the chock, according to the report.
The agency also reports that "upon inspection one of the cars of the unoccupied train was found to have thermally damaged wiring and water in electrical connection boxes on the car."
The NTSB issued the following "urgent" recommendations:
- "Review your operating and maintenance procedures for stored unoccupied cars to ensure the propulsion and brake systems are left in a condition that would not facilitate unintended movement."
- "Immediately implement redundant means of stopping unintended rail car movements, such as wheel chocks or a derail."
The report details that NTSB is still investigating the issue and noted that the matter should be "addressed expeditiously to prevent a recurrence." In a letter to the CTA, the request asks for a response within 30 days detailing the actions the transportation agency has taken or intends to take to address the problems.
National Transportation Safety Board Safety Recommendation by wednesdayjournal