Don Ross, the regional senior investigator, made the comments on Friday, while releasing the final report on the CN Rail derailment that occurred in Plaster Rock, N.B., in January 2014.
The shattering of a wheel with an undetected defect triggered the derailment of the 122-car train, which resulted in the rupture of two crude tank cars, a large fire, and evacuation of the area, Ross said during a news conference in Dieppe.
The investigation found the two crude tank cars were older Class 111 tank cars, built in 1984 and 1996 — similar to those in the crash in Lac-Mégantic, Que.
They dumped approximately 230,000 litres of crude oil, feeding the fire, which melted pressure relief valves on the two cars carrying liquefied petroleum gas.
No one was injured, but about 150 people living within a two-kilometre radius of the crash site were forced to leave their homes for several days.
In May, Transport Canada announced new regulations for more robust tank car standards and requirements for rail companies to retrofit older cars, and many of the more recently manufactured cars, by 2025.
"While this is a positive development, the board is concerned with the amount of time it would take to implement these changes," said Ross.
"We think that these timelines are longer than they need to be … We are in favour of more aggressive timelines, certainly.
"We've spoken with the tank car manufacturers about their capacity, their ability to respond to these aggressive timelines. The folks that we talked to to were quite positive as far as, basically 'Give us the orders and we'll get at it.'"
Until the cars are replaced with more robust ones, Ross says there is an ongoing risk of significant damage to people, property and to the environment.
"To offset, to address some of the risks of that, then perhaps you have a look at your train speeds, your train routing, how you're handling those trains, your inspection methods," he said.
CN Rail will be allowed to respond to the report's findings and recommendations, which will be made public, along with TSB's response to CN's comments.
Shattered wheel 'very rare event'
The CN Rail train was travelling from Toronto to Moncton, when it derailed in Wapske, N.B., on Jan. 7, 2014.
Of the 19 cars that jumped the tracks, five were carrying crude oil from western Canada to the Irving Oil refinery in Saint John and four were carrying liquefied petroleum gas.
"The investigation determined that a wheel on the thirteenth car shattered due to an area of subsurface porosity that led to fatigue cracking," stated the TSB.
"The subsurface porosity was not detected during the ultrasonic testing when the wheel was manufactured in 1991 or when it was reprofiled in 2006."
Ross described the breaking of a wheel as "a very rare event."
The defect that led to the wheel shattering is normally something that becomes apparent in the early life of a wheel and not one that is more than 20 years old, he said.
"These type of failures certainly don't happen frequently at all," said Ross. "There was only three broken wheel failures in total and all three weren't this type that happened here.
"[These types of failures] normally happen with wheels that are new in service," said Ross. "The longer they're in service, the less likely this type of problem."
Wheels manufactured now undergo an ultrasonic inspection of the tread area to check for areas of porosity, or tiny holes.
Ross said investigators were not able to review ultrasonic tests carried out on the wheel in 2006. Railway companies are now required to retain such tests for 10 years, with that requirement implemented in 2010.
Emergency response appropriate
The TSB found the train crew members handled themselves appropriately.
They received a warning from a railside testing device at Plaster Rock that something was wrong with one of the cars. They started to stop the train and were reducing speed at the time of the derailment. They quickly got out, assessed the situation, and sounded the alarm.
CN spokesman Jim Feeny was unavailable for an interview on Friday, but in an emailed statement, he said: "As noted by the TSB, the emergency response to this incident was appropriate and effective.
"CN thanks the agencies involved in the coordinated, comprehensive response – particularly the Plaster Rock Fire Department, and the Mayor and citizens of Plaster Rock, whose support was unstinting," he said.
Feeny also noted CN developed new external communications protocols during the Plaster Rock emergency response, to ensure all affected stakeholders received timely, accurate information.
"These protocols are now part of our standard response to all major incidents," he said.
The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences.
Its function is not to assign fault or determine civil or criminal liability. Its sole aim is to improve transportation safety.