News release
Associated links (R21S0048)
Undetected rail flaw led to broken rail and subsequent derailment near Silton, Saskatchewan
Winnipeg, Manitoba March 26, 2024 — Today, the Transportation Safety Board of Canada (TSB) released its investigation report (R21S0048) into the 2021 derailment of a Canadian Pacific Railway (CP) freight train.
On October 16, 2021, a CP train hauling 200 freight cars loaded with potash, was proceeding south on the Lanigan Subdivision when it experienced a train-initiated emergency brake application near Silton, Saskatchewan. The train came to a stop and a subsequent inspection by the conductor determined that 27 freight cars had derailed into a large pile. Many had been breached and their contents subsequently released. There were no injuries, and no dangerous goods were involved.
The investigation determined that the train derailed when the west rail broke as a result of pre-existing fatigue cracks that had spread down to the base of the rail in a sudden overstress as the train passed over it. The frequency of rail flaw detection (RFD) testing on the Lanigan Subdivision exceeded regulatory requirements. Testing was performed shortly before the accident and no rail defects were identified. While RFD testing is a reliable and cost-effective method to detect rail flaws, its accuracy is limited by current technology and other factors such as rail surface conditions and the size and type of defects. Given these limitations, rails with internal defects can sometimes be misclassified as free of defects, increasing the risk of failure and subsequent derailment.
On July 29, 2022, CP implemented a Rail Integrity Non-Vital Overlay Detectors system on the Lanigan Subdivision, which sends automatic notifications to CP’s Operations Centre in the event of a broken rail, rail gap, loose joint, or rail joint pull-apart. The notifications provide advance warnings that allow the Operations Centre to stop a train before it encounters any such track discontinuities in non-signaled territory.
See the investigation page for more information.
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: 819-360-4376
Email: media@tsb.gc.ca