An undetected defect led to a broken rail, the derailment of 26 cars and a flash fire on a Canadian National Railway line near Clair, Sask., two years ago, says the Transportation Safety Board of Canada.
About 50 people were evacuated and a highway closed as a result. No one was injured.
At a Saskatoon news conference, the board revealed that the train derailed due to a “sudden and catastrophic failure” of a rail that ultimately destroyed nearly 200 metres of track.
“Poor rail surface conditions had masked the presence of this defect and reduced the effectiveness of visual inspections and ultrasonic inspections,” the board said.
The TSB said ultrasonic testing hasn’t picked up defects a total of seven times in the past 10 years.
At Clair on Oct. 7, 2014, the CN freight train bound for Edmonton from Winnipeg derailed 26 cars, including six Class 111 tankers loaded with dangerous goods. Two of the cars contained petroleum distillates, and emergency responders flared product that had spilled on the ground, which ignited vapours still in the tanker and led to the fire.
Two responders had to avoid a fireball.
The TSB said the responders were likely tired and didn’t consider all of the risks associated with flaring. It also found that CN did not document the close call or proactively share the information.
The report identified deficiencies in provincial incident commander training, emergency response activity monitoring and post-response follow-up.
“If company and industry guidance is not followed and close calls during emergency response activities are not properly documented and openly shared among all responding agencies, similar circumstances could occur, putting emergency response personnel at risk,” said lead TSB investigator Rob Johnston.
CN has since improved its procedures, and the provincial environment ministry has ensured its incident commanders are appropriately trained.