News release

Associated links (R17T0164)

A unique combination of six non-condemnable factors led to July 2017 “wheel-climb” derailment in Strathroy, Ontario

Toronto, Ontario, 9 October 2018 – In its investigation report (R17T0164) released today, the Transportation Safety Board of Canada (TSB) determined that a combination of six conditions contributed to the wheel of a covered hopper car climbing over the rail on the high side of a curve, resulting in a derailment in July 2017 in Strathroy, Ontario.

On 19 July 2017, a westbound Canadian National (CN) freight train derailed 14 cars near the Metcalfe Street West crossing in the town of Strathroy, Ontario. One of the cars that derailed was a dangerous goods residue tank car that had last contained liquefied petroleum gas. It came to rest on its side. There was no release of dangerous goods and there were no injuries.

The investigation found that a wheel on the 109th car in the train, a covered hopper car loaded with cement, had climbed the north rail of a slight left hand curve, immediately west of the Carroll Street crossing. The lead wheels on the 110th car, a residue tank car, also derailed. These 2 cars continued in a derailed condition for about 1.15 miles (1.85 km) until the train traversed the Caradoc Street crossing. At that point, the cement car re-railed itself, but the residue tank car remained derailed. Upon reaching the platform of the VIA Rail station in Strathroy, the residue tank car separated from the cement car, leading to the derailment of 13 additional cars.

The investigation determined that there were numerous “non-condemnable” factors that contributed to wheel climb that led to the derailment, including a number of mechanical conditions on the first car to derail and various track conditions in the vicinity.

Following the occurrence, CN purchased specialized tools and equipment for its MacMillan Yard facility to repair stabilized trucks. CN also ensured that the importance of the condition of coupler and truck components when performing safety inspections is being discussed with mechanical staff during daily job briefings.


The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-994-8053
Email: media@tsb.gc.ca

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