Rail Safety Advisory 617-03/20

Place du Centre
200 Promenade du Portage, 4th Floor
Gatineau QC  K1A 1K8

04 March 2020

Letter addressed to:
Director General, Rail Safety
Transport Canada
14th Floor, Enterprise Building
427 Laurier Avenue
Ottawa, Ontario
K1A 0N5

On 06 February 2020, a Canadian Pacific Railway (CP) petroleum crude oil unit train consisting of 2 distributed power locomotives (1 on the head end and 1 on the tail end), 104 tank cars loaded with petroleum crude oil (UN 1267, Class 3, packing group I) and 2 covered hopper cars loaded with sand (108 rolling stock in total) was proceeding eastward at about 42 mph on the CP Sutherland Subdivision. The train weighed 14 896 tons and was 6445 feet long. This was a key train^{Footnote 1} operating on a key route.^{Footnote 2}

At about 0615 Central Standard Time, the train experienced a train-initiated emergency brake application at about Mile 43.4, about 1 ½ miles west of Guernsey, Saskatchewan.  Subsequent examination identified that 32 tank cars (lines 32 to 63 inclusive) had initially derailed at Mile 43.64, just west of the Bloomfield Road passive crossing located at Mile 43.63 (Figure 1).

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The derailed cars were all DOT 117J100-W specification tank cars. One derailed car remained upright, was otherwise unaffected and was subsequently re-railed. Of the remaining 31 derailed cars, 19 were involved in a pool fire west of the crossing. The remaining 12 cars derailed on top of and east of the crossing. These 12 cars were not initially on fire (TSB Occurrence R20W0025).

There were no injuries reported. As a precaution, there was an evacuation of about 85 people from the town of Guernsey. The temperature at the time of the accident was about −18 °C. Post-accident site examination suggests that 27 of the cars lost product and released an estimated 1.6 million litres to either the ground or atmosphere. No waterways were affected. The specific number and type of tank car breaches sustained during the derailment has yet to be determined. A review of the locomotive event recorder download determined that the train was handled in accordance with regulatory and company requirements. To date, no mechanical defects were observed on any of the rolling stock that could be considered causal.

A visual inspection of the head-end portion of the train that did not derail was conducted. On the north side of the train, impact marks were observed on the wheel treads of tank cars located in the 28th, 29th and 31st positions behind the head-end locomotive. The marks observed were consistent with impact that occurs when a wheel tread contacts a broken rail.

The petroleum crude oil was transported in DOT 117J100-W tank cars, which are the newest tank cars built to transport Class 3 flammable liquids. The type of petroleum crude oil involved in this occurrence had properties consistent with petroleum crude oil that the TSB has evaluated in previous investigations involving crude oil.^{Footnote 3}

The CP Sutherland Subdivision extends westward from Wynyard, Saskatchewan (Mile 0.0), to Saskatoon, Saskatchewan (Mile 113.5). Train movements on the subdivision are governed by the Occupancy Control System as authorized by the Canadian Rail Operating Rules and supervised by a CP rail traffic controller located in Calgary, Alberta. The CP Sutherland Subdivision is dark territory (i.e., there is no wayside signal system and associated track circuits to govern movements and aid in the detection of broken rails).

In the area of the derailment, the single main track was classified as Class 4 track according to the Transport Canada (TC)–approved Rules Respecting Track Safety otherwise known as the Track Safety Rules (TSR). The authorized track speed for eastbound freight trains through the area of the derailment was 45 mph. At the time of the occurrence, there were no track slow orders in effect.

Over the past 10 years or so, train operations have evolved and there have been a number of operational improvements implemented throughout the rail industry, such as the proliferation of distributed power technology. These advancements have facilitated more effective management of in-train forces allowing for longer, heavier trains.

Similarly, train traffic has evolved and generally increased as more dangerous goods (DG) are transported in either large blocks of cars within a merchandise train or as unit trains that transport a single DG product such as petroleum crude oil. For example, in 2017, CP transported 10 523 tank car loads of petroleum crude oil on its Sutherland Subdivision. This had increased to 77 312 tank car loads in 2019.  

In 2015 the TSB investigated 2 Canadian National Railway (CN) derailments on the CN Ruel Subdivision that involved the release of large volumes of petroleum crude oil.^{Footnote 4} In both cases, amongst other factors, the cause of the derailment was related to either broken joint bars or a broken rail. The investigations found that CN’s safety management system relied on reactive indicators, and did not anticipate the need for increased track maintenance in light of significant increases in volumes DG traffic and tonnage. The investigations also identified that if company safety management system risk assessments do not adequately consider increases in traffic tonnage, the use of heavier rail cars and the potential for more rapidly degrading track structure, regular track maintenance activities may no longer be sufficient to maintain track to the required standards, increasing the risk of track infrastructure failures.

Following these derailments, CN made a significant capital investment in the Ruel Subdivision track infrastructure and improved its track inspection and maintenance practices. While the Ruel Subdivision is still primarily Class 4 track, there has not been a significant main track train derailment on the subdivision since March 2015.

In this occurrence (R20W0025), the derailment occurred at a speed that was permitted by the Rules Respecting Key Trains and Key Routes in force at the time and the crude oil was transported in DOT 117J100-W tank cars, which have significant design improvements when compared to legacy DOT 111A tank cars. Despite using the best tank cars available, about 27 of the tank cars released an estimated 1.6 million litres of product. This suggests that the recent tank car design improvements alone are insufficient to fully mitigate the risk of adverse consequences resulting from derailments involving DG.

Another way that the rail industry manages the risk of derailment is through the reduction of train speed. Historically, train speeds have been based on the class and the condition of the track as well as any equipment and environmental restrictions that may apply. Permanent and temporary track slow orders can be implemented to restrict train speed when required for operational or track maintenance purposes. These have been a long-standing practices in the industry.

Since 01 January 2015, the TSB has deployed to 7 train derailments involving tank cars that were transporting petroleum crude oil. Six of these derailments resulted in a significant release of petroleum crude oil (Appendix A). A review of the accidents revealed that each of the 7 derailments occurred on a key route on which the track was maintained in accordance with the TSR Class 3 or 4 standard. In each case, the derailments occurred as a result of a broken rail, broken joint bars or other track infrastructure condition. Six of the 7 derailments occurred during the winter months.

Although CP maintained the Sutherland Subdivision to a Class 4 standard, in the 2 months between 09 December 2019 and 06 February 2020, there were 2 significant derailments near Guernsey, both of which resulted in the release of substantial amounts of petroleum crude oil. While both investigations are ongoing, in both cases, the suspected cause appears to be related to a broken rail. Considering the 2015 CN derailments on the Ruel Subdivision and the recent CP experience on the Sutherland Subdivision, maintaining track to the TSR minimum standards on key routes may not be adequate to protect against derailments.  

As train operations have evolved, the TSR have not kept pace. The current TSR came in to force on 25 May 2012 almost 4 years before, the TC-approved Rules Respecting Key Trains and Key Routes came into force (February 2016). While the TSR establish minimum standards for track infrastructure, there are no provisions in the TSR to address the need for enhanced track standards for key routes despite sometimes significant increases in DG traffic volumes.  

In order to reduce the frequency and mitigate the risks associated with accidents involving key trains on key routes, it is imperative that the track infrastructure is adequately maintained. Considering that the underlying causes of the 7 accidents identified were all related to failures of track infrastructure, Transport Canada is advised that the current TSR do not address the increased risks associated with the operation of key trains. Therefore, Transport Canada should consider revising the Rules Respecting Track Safety to include enhanced track standards for key routes.

The TSB would appreciate being advised of TC’s position on this issue, and what action, if any, will be taken in this regard. Upon completion of the investigations into occurrences R20W0025 and R19W0320, the Board will release its investigation reports.

Yours sincerely,

Original signed by

Dan Holbrook
Acting Director,
Investigations, Rail/Pipeline

CC.

• Associate Administrator for Railroad Safety, Chief Safety Officer, Federal Railroad Administration (FRA)
• Assistant Vice President, Safety and Sustainability, Canadian Pacific Railway
• Assistant Vice President, Safety, Canadian National Railway
• Senior Director, Operations and Regulatory Affairs, Railway Association of Canada

Appendix A – Other derailments since 2015 that involved petroleum crude oil

Background information

Occurrence No.

• R20W0025
• R19W0320