Undetected fracture derails train: Transport Safety Board

 Ignition of product pool. (Source: Assistant fire chief, Wadena Fire Department)

Ignition of product pool. (Source: Assistant fire chief, Wadena Fire Department)

After just over the two-year mark, the results of the investigation into the Clair derailment were released last week.
At a news conference in Saskatoon on Nov. 16, Transport Safety Board (TSB) released its findings into the Oct. 7, 2014, derailment citing, “the sudden and catastrophic failure of one of the rails that occurred under the train” was the cause.
The accident led to a huge fire with billowing smoke from petroleum distillates contained in two of the derailed tankers. The cars left the track at at 10:30 a.m., some four and half hours after leaving Canora. While en route, according to the TSB, the train passed a number of roll-by inspections at crew changes, as well as a wheel-impact load detector and several hot bearing detectors, in which no significant defects were identified.
Through sheer coincidence the crew, which consisted of one engineer and a conductor, were on the radio to the rail traffic controller discussing an unrelated incident when they saw the train derail. After immediately relating the incident, they disconnected the three locomotives and moved them up the track.
As the Wadena News reported on Oct. 13, 2014, first responders on the scene would have been met with “a scene of destruction … several rail cars were piled into two distinct mangled messes. Large shards of shattered steel and loose wheels could be seen in the ditch … One pile was burning fiercely; the roar of an intensely hot fire could be heard by curious bystanders …”
In its report, the TSB said that 26 cars from the 32nd to the 57th had come to rest in “various positions,” with the 51st and 52nd tanker spilling their contents of petroleum distillates. The liquid ignited, with nearly all the contents being consumed in the ensuing fire. Four other tanker cars derailed, of which contained sodium hydroxide and hydrochloric acid, of which none were ruptured. All six tank cars were of the class 111 type that as of Nov. 1, 2016, cannot be used for the transportation of crude oil.
The TSB reported that a “poor rail surface condition masked the defect,” a railhead with an 80 per cent fracture, which “reduced the effectiveness of visual and ultrasonic inspections.”
Investigator in charge Rob Johnston said, “CN far exceeded the regulatory requirements because they did recognize that this part of the track did have issues.”
In fact in the previous year CN had tested the line on several occasions. The TSB report went on to say that the increase in traffic on a line from 1959 would also have had an effect, even though it was deemed “adequate” as a secondary line.
There have been questions in the past about the size and length of trains on secondary lines. This particular CN train consisted of three locomotives, 40 loaded cars, 53 empty cars, and seven residue tank cars. In total it weighed 6,727 tons and was 6,142 feet in length.
The TSB also said that in the past ten years they investigated seven occurrences that caused derailments similar to this, four at CN and three at CP.
The TSB also noted some shortcomings into the emergency response from CN as well as in the training of the government’s incident commanders. The report cited that with multiple agencies and companies responding, a unified command system was established with the Wadena Fire Chief designated the incident commander. Although they “were experienced fire fighters, they were not trained to NFPA 472 and had no experience with this type of response.” Consequently the Ministry of the Environment became the “defacto incident commander within the unified command system, assumed the role of the authority having jurisdiction, and became responsible for documenting the response.”
As there was cause for concern from the smoke and possible toxicity, an evacuation was ordered of Clair, 45 landowners and anyone within a 5-km radius.
The TSB, however, were also critical of CN the practice of flaring that lead to a flashover. The incident, caught on camera by Wadena’s deputy fire chief, Brian Weber, ocured when one of the dangerous goods cars, with approximately 20-30 per cent of its load remaining, was being pulled across an adjacent shallow ditch that evening during clean-up. The car rolled a quarter-turn spilling 2400- 3200 litres of petroleum distillates out of a 65-inch thermal tear then pooled on the ground, stated the report.
The CN’s senior dangerous goods officer (SDGO) along with the “AVP,” assistant vice-president of the safety and emergency response, decided to ignite the liquid by throwing a flare at it, also known as flaring. The reason for this was it was felt the fumes could drift to a burning box car and ignite. However, when the product ignited and began to burn, an unexpected flash occurred as the vapours inside the breached tank car ignited sending a large fireball toward the two men. Both took evasive action as the fireball blew over them and then quickly extinguished itself.
“A flash fire occurred when vapours inside a tank car ignited, which subsequently sent a huge fireball toward two emergency responders who had initially carried out the flaring process,” Johnston said. “CN had failed to follow its own safety procedures with the admission of any documentation over the incident and also not sharing information with others about the incident for use in future events.”
A spokesman from CN, Patrick Waldron said that CN’s dangerous goods officers have reviewed response practices to improve its emergency responses and procedures. Waldron also indicated the company has since invested heavily in the rail line, as residents of Wadena and Clair have seen with the renewal of miles of track over recent months, all to reduce the risk of further incidents.
Of all the rail networks in the world Canada has the third largest network, which transports the world’s fourth-largest volume of goods. Canadian rail moves 70 per cent of the country’s surface goods and carries 70 million people. With the thousands of crossings and interaction rail has with pedestrians and motorists, the odds of accidents remain high.

By Andy Labdonnewpic6

Wadena News


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