Operator fatigue cause of train derailment: TSB
FEDERAL (Canadian OH&S News)
FEDERAL (Canadian OH&S News)
A Transportation Safety Board of Canada (TSB) report into a train derailment last year has brought the issue of operator fatigue back into the spotlight.
Released on December 7, the TSB report examined the 21-car derailment of a Canadian National (CN) freight train near Falding, Ontario on October 1, 2010. Although the derailed cars included eight loaded tank cars containing non-odorized liquefied petroleum gas and seven containing fuel oil, no product was released and there were no injuries.
The TSB investigation found that the locomotive engineer was insufficiently rested to be engaged in safety critical tasks. In fact, on the night before the occurrence, the worker only slept between one and one-and-a-half hours before he was called to work at 4:45 am. He began his shift at 6:25 am.
Under Transport Canada’s work-rest regulations, companies expect that when called for work, typically with a two-hour notice, operating employees accept the work, arrive on time and be fit to perform their duties safely for up to 12 hours. If an employee does not accept the work, the report says, they are likely to face some form of discipline.
“The locomotive engineer recognized he was tired when accepting the assignment, but knew that refusing an assignment when called could result in loss of wages due to a missed trip and/or potential company discipline,” the TSB report says.
“When faced with loss of wage and/or potential company discipline, there is an increased risk that a fatigued employee will accept work, compromising safe train operation.”
The report notes that the engineer’s fatigued state was “compounded by the challenge of operating an unfamiliar train during an unplanned braking event in undulating territory with a number of curves.”
Fatigued engineer could not recall signals
On the morning of the accident, the conductor briefly left the cab seating area and was not in a position to observe signals.
Because the engineer could not recall a previous advance signal and the conductor was not present when the train passed it, the train crew could not positively identify the signal and prepared to make an unplanned stop in advance of the next signal using the train’s dynamic brake.
The engineer then applied the brake in a “rapid non-standard fashion” and did not account for a run-in of train slack from the trailing tonnage which was still on a descending grade, the report says, noting that this contributed to the accident.
At the time of the incident, the industry was in the process of implementing new fatigue management guidelines, but it was still left to employees to determine whether they were fit to work.
On February 23, 2011, the federal transport minister approved revisions to Transport Canada’s Work/Rest Rules for Railway Operating Employees. The rules require railway companies to implement fatigue management plans, taking into account such items as train size, complexity, traffic density, traffic patterns, run length and geographical considerations.
After the incident, CN implemented a number of practices and programs to mitigate crew fatigue, the report notes. CN’s fatigue management plan, which lays out initiatives related to alertness strategies and work scheduling, among others, “is currently being enhanced with additional features as part of the recent amendments” to the work/rest rules, the report adds.