SASKATOON, Nov. 16, 2016 /CNW/ - In its investigation report (R14W0256) released today, the Transportation Safety Board of Canada (TSB) determined that a broken rail, due to an undetected defect, led to the October 2014 derailment of a Canadian National Railway (CN) freight train near Clair, Saskatchewan. There were no injuries, although a flash fire during the emergency response put CN emergency responders at risk.
On 7 October 2014, a CN freight train proceeding westward from Winnipeg, Manitoba, destined to Edmonton, Alberta, derailed 26 cars, including six Class 111 tank cars loaded with dangerous goods, near Clair, Saskatchewan. Two of the tank cars, which were loaded with petroleum distillates, released product that subsequently caught fire. As a precaution, 50 residents within a five-mile (8 km) radius were evacuated and Provincial Highway 5 was closed. Approximately 650 feet of track was destroyed.
This investigation identified risk factors related to the transportation of flammable liquids by rail, and safety management and oversight as outlined in the TSB Watchlist. Two of the Class 111 tank cars released product, and the damage to these cars was consistent with failures noted by the TSB in other investigations. The TSB made recommendations (R14-01 and R14-02) to address these issues as part of the Lac-Mégantic investigation.
The investigation determined that the train derailed when a sudden and catastrophic failure of one of the rails occurred under the train, due to the presence of an undetected defect. Poor rail surface conditions had masked the presence of this defect and reduced the effectiveness of visual inspections and ultrasonic inspections. Including this occurrence, the TSB has investigated seven occurrences in the past 10 years involving a rail break due to a pre-existing rail defect that was not detected by ultrasonic testing.
During the emergency response, CN emergency responders were flaring (igniting) the contents of one of the breached tank cars that had overturned and released product which pooled on the soil below the tank car. A flash fire occurred when the vapors inside the tank car ignited, sending a large fireball towards the two emergency responders who were carrying out the flaring activity. Both emergency responders took immediate evasive action to avoid the flash fire, which quickly extinguished itself.
The investigation found that CN emergency responders, who were likely fatigued, did not consider all the risks associated with the flaring activity prior to igniting the pool of product released from the tank car. CN did not document the close-call during the flaring activity or proactively share the information with any outside agencies, highlighting gaps in CN's reporting and/or procedures.
The investigation also 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 TSB manager and lead investigator Rob Johnston.
Following the occurrence, CN improved procedures for flaring tank cars and enhanced its documentation requirements for emergency response activities. The Saskatchewan Ministry of the Environment enhanced its procedures for ensuring that incident commanders are appropriately trained and site monitoring activities are established when responding to emergencies involving dangerous goods.
See the investigation page for more information.
The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
The TSB is online at www.tsb.gc.ca. Keep up to date through RSS, Twitter (@TSBCanada), YouTube, Flickr and our blog.
SOURCE Transportation Safety Board of Canada
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