Wheel with undetected defect to blame for derailment near Plaster Rock, N.B.: safety board

The Transportation Safety Board of Canada (TSB) said that a wheel with an undetected defect was responsible for a derailment and fire involving a Canadian National (CN) train near Plaster Rock, N.B. in January 2014.

In its investigation report released on Friday, the TSB said that a wheel on the 13th car shattered due to an area of subsurface porosity that led to fatigue cracking. This porosity was not detected during the ultrasonic testing when the wheel was manufactured in 1991, or when it was reprofiled in 2006. The broken wheel and the wheel on the opposite side of the same axle derailed inside the track gauge, causing track damage and leading to the derailment of the 19 cars and the mid-train locomotive, the report said.

Related: Fatigue blamed for wheel failure in New Brunswick train derailment: safety board

The derailment occurred on Jan. 7, 2014, when a CN freight train travelling from Toronto to Moncton derailed locomotive near Plaster Rock. Seven Class 111 tank cars carrying petroleum crude oil and other dangerous goods and five Class 112 pressurized tank cars carrying butane were among those that derailed. Approximately 230,000 litres of crude oil spilled from the tank cars and caught fire. About 150 residents were evacuated within a 1.6 kilometre radius of the fire. A total of 350 feet of track was destroyed, and there were no injuries. [click image below to enlarge]

The investigation found that “appropriate and effective measures were taken in response to the emergency. The environmental response plan and derailment site remediation ensured a minimal and contained environmental impact.

Related: Evacuees return home four days after New Brunswick derailment, trains running

Transportation of flammable liquids by rail is a TSB Watchlist issue and the safety board is calling on railway companies to conduct route planning and analysis, and perform risk assessments to ensure that risk-control measures are effective. “This accident also underscores the TSB’s longstanding call for tougher standards for tank cars transporting crude oil to reduce the likelihood of a dangerous goods release during accidents,” the TSB said in a statement, adding that on May 1, Transport Canada introduced new regulations for a more robust tank car standard, retrofit requirements and an implementation timeline.