High temperatures caused Saint John derailment, preliminary findings indicate
CN Rail continues to investigate, but heat can cause track to expand and move, known as sun kink
High temperatures caused an eight-car CN Rail derailment over a gas pipeline in east Saint John last Saturday, according to the preliminary investigation by the company.
"Preliminary findings indicate that high rail temperatures are the cause," confirmed Department of Transportation and Infrastructure spokesperson Jeremy Trevors.
Steel expands in high heat conditions and can cause track to move under a moving train, said Mary Keith, a spokesperson for NB Southern Railway, which leases the track from CN Rail.
This is sometimes referred to as sun kink, she said.
It reached nearly 28 C in Saint John that day, according to Environment Canada.
CN Rail officials did not respond to a request for comment Thursday or Friday.
In an emailed statement Wednesday, CN spokesperson Tiffany Edwards said only, "The cause of the incident is under investigation."
The train carrying potash, wood chips and an empty tank car that had contained sulphur derailed Saturday around 6:45 p.m. parallel to Rothesay Avenue, causing the evacuation and early closure of some area businesses and two street closures.
One witness said it "felt like an earthquake" and commented it could have been a "catastrophic event" if the car that contained liquid sulphur residue from its previous load had been full when it landed less than two metres away from a parked vehicle.
No leaks, fires or injuries resulted from the derailment, but it did down a power line knock over two lamp posts.
Cleanup took 5 days
There have been a number of minor derailments in that area over the years.
In May 2017, three NB Southern tanker cars carrying crude oil derailed. It was one of "under half a dozen" derailments in the previous five months, a fire official had said at the time.
The cleanup of Saturday's derailment was completed Thursday, said Keith. NB Southern assisted CN Rail, using cranes to right the derailed cars without any loss of product or interruption of train traffic, she said.
Keith could not comment on the investigation, directing inquiries to CN Rail.
Normally, it's up to the railway to identify the cause of a derailment, said the Department of Transportation and Infrastructure (DTI) spokesperson.
"The level of follow-up by DTI would depend on the circumstances," Trevors said in an emailed statement.
He did not indicate what DTI plans to do in this case.
The department will continue to work closely with Transport Canada to mitigate risks.- Jeremy Trevors, Department of Transportation and Infrastructure spokesperson
Trevors did say, given the preliminary findings, DTI does not anticipate requesting a Transportation Safety Board of Canada investigation.
The province regulates shortline railway operation under the Shortline Railways Act, which is administered by DTI.
The TSB is responsible for federally regulated modes of transportation but could investigate a provincially regulated railway if requested to do so by the province.
Transport Canada conducts inspections on behalf of the province on shortline railways within New Brunswick, said Trevors.
"The department will continue to work closely with Transport Canada to mitigate risks," he said, without elaborating.
The Transportation Safety Board has assessed the preliminary information gathered on the derailment and deemed it a class 5 occurrence, in accordance with its Policy on Occurrence Classification, said spokesperson Chris Krepski.
"This means that the investigation is limited to data gathering and the data are recorded for statistical reporting and future analysis," he said in an email.
Travelling 13 km/h
The preliminary report shows the CN-owned train was travelling at just under 13 kilometres per hour when it derailed.
Five of the derailed cars contained potash, two contained woodchips and the eighth contained residue of its previous load, liquid molten sulphur.
The track is owned by CN but is leased by NB Southern, part of New Brunswick & Maine Railways, a subsidiary of J.D. Irving Ltd. It is provincially regulated because it does not cross provincial borders, according to Krepski.
Track inspected 3 minutes before train due
The track was visually inspected twice by two different trained NB Southern personnel prior to the derailment, according to Keith, once the day before and again just three minutes before the arrival of the train.
"No defects [were] noted on the tracks, gauges or switch," she said.
Asked if it had been business as usual after the derailment, Keith said the only difference is that NB Southern has "adjusted" its operations "because of the heat."
"We are operating more in the evening and early morning, where there isn't as much of an impact on track," she said.
"Heat is an issue this time of year and heat is especially an issue as it relates to the current situation in the province with the heat warnings and high temperatures and what we're seeing by way of extreme fire risks."
On Friday, Keith clarified that NB Southern had adjusted its operations prior to the derailment.
"The railway has been monitoring and adjusting the timing of rail operations due to extreme heat and fire risk conditions for the past [three] weeks in both NB and Maine," she said in an emailed statement.
"Foggy conditions in [Saint John] are not representative of the extreme heat we are seeing inland."