Associated links (R15H0013)
Kathy Fox
Chair, Transportation Safety Board of Canada
and
Rob Johnston
Manager, Central regional operations, Transportation Safety Board of Canada
Thunder Bay, Ontario, 16 February 2017
Check against delivery.
Kathy Fox
Good morning,
During a three-week span in early 2015, Canadian National Railway experienced three significant train derailments in Northern Ontario. We are here today to discuss the results of the TSB's investigation into the first accident. Information relating to the others will be released at a later date.
On February 14, a CN unit freight train transporting 100 tank cars loaded with petroleum products derailed at Mile 111.7 of the Ruel Subdivision. 29 tank cars of petroleum crude oil left the tracks, and 19 were breached, releasing about 1.7 million litres of product. The crude oil ignited, and the resulting fires burned for five days.
The train was travelling at 38 mph at the time. This was less than the maximum track speed of 40 mph. As such, the TSB is concerned that currently permitted speeds are too high for key trains transporting Class 3 flammable liquids. Moreover, we are recommending that Transport Canada study all factors that increase the severity of derailments involving dangerous goods—including speed—that TC develop mitigating strategies, and then amend the rulesaccordingly.
I'll talk more about those rules, and what that means, in just a few minutes. But first I'll turn things over to the Regional Manager, Mr. Rob Johnston. He'll walk you through the sequence of events, explaining the specifics of how—and why—this derailment occurred.
Rob Johnston
Thank you, Kathy.
When two pieces of rail meet, they are held together by 2 “joint bars” on either side of the rail. Joint bars, like all sections of track, are subject to regular track inspections.
Just after 11:30 pm on the night of the occurrence, as the lead locomotives and the first few tank cars passed over a rail joint, both joint bars failed and 29 tank cars loaded with crude oil derailed.
The TSB's investigation found that pre-existing fatigue cracks in the joint bars had gone unnoticed in previous inspections. Once these reached a critical size, the combination of cold — it was −31°C at the time — and repetitive poundings from the wheels of heavy unit trains caused the joint bars to fail.
A newly hired track maintenance employee was responsible for inspecting and monitoring the joint. Although there were prior indications of degrading joint conditions, the employee lacked the experience to recognize them.
This was because CN's training program was insufficient to aid the employee in understanding all the factors that could lead to joint defects. Neither was there adequate mentoring or support for the employee during on-the-job training while in the field.
Since the tragedy at Lac-Mégantic in 2013, the TSB has pushed for tougher standards for tank cars. That accident involved the oldest of the three main types of general-service tank cars: the so-called “legacy” DOT 111s, which offered the least protection and safety features.
In this accident, the derailed cars were built to a higher standard, known as CPC-1232. Although these cars feature tougher steel and half-head shields, they do not all have jackets or thermal protection, and the speed of the train had a direct impact on the severity of the tank-car damage. Consequently, we found similar performance issues as at Lac-Mégantic.
In this accident:
- The shells on eight cars breached, releasing crude oil and igniting a large pool fire.
- Seven other tank cars, lying in this pool, sustained thermal tears, releasing yet more product.
As we all know, crude oil can be highly volatile, and in this case it led to fires that burned for five days.
Since the accident, CN has:
- Replaced 44 miles of rail on the Ruel subdivision;
- Modified its track-inspection guidelines,
- Improved employee training, and mentoring,
- Purchased automated joint bar inspection equipment, and
- Implemented a comprehensive environmental plan to restore the site to pre-accident conditions.
However, many of the same risk factors from this accident could apply almost anywhere else in the country. That's why more must still be done.
The TSB Chair will now talk more about what the TSB wants done to improve rail safety—wherever dangerous goods are being transported.
Kathy Fox
Thank you, Rob.
After Lac-Mégantic, Transport Canada announced a new standard for tank cars carrying flammable liquids. These cars, known as TC-117, have thicker steel and additional safety features such as full head shields, jackets, and thermal protection. Furthermore, last fall, the minister of transport announced an accelerated phase-out of the “legacy” DOT 111 tank cars like those used in Lac-Mégantic.
However, given the known deficiencies with the CPC 1232's and the fact that they won't be fully phased out until 2025, the risk is clear. Until then, less-robust tank cars, such as those involved in this occurrence, will continue to be allowed to transport Class 3 flammable liquids.
Moreover, since this derailment occurred at a speed below the maximum permitted, the TSB is concerned that such a limit may not be sufficient for some trains—particularly unit trains carrying flammable liquids.
Speed, however, is not the only variable in determining the severity of an accident. A train's “risk profile”—the type and amount of product, as well as how that product is distributed within the train consist—is also critical. The TSB therefore recommends that Transport Canada conduct a detailed study of all the factors that increase the severity of derailments involving dangerous goods, so that TC can then identify appropriate mitigating strategies and amend the Rules Respecting Key Trains and Key Routes accordingly.
This accident occurred on an isolated stretch of rail in Northern Ontario, and thankfully no one was injured. But so long as the same risks exist—track-maintenance issues, railway personnel training, train speed, and tank cars that aren't sufficiently robust—the consequences of the next rail accident may not only be environmental. That's why the issue of transporting flammable liquids by rail has been on the TSB's Watchlist since 2014 … and why it will remain there until these risks are significantly reduced.