IGNACE, ON — Unstable ground beneath the tracks led to a major derailment on the CPR line near Ignace in May 2020.
The Transportation Safety Board of Canada reached that conclusion after investigating an incident that saw 53 hopper cars filled with grain derail just west of the community.
Grain was spilled from several of the cars, but there were no dangerous goods involved, and no one was injured.
The train had 222 cars and three locomotives, was 3.8 kilometres long, and was travelling at 74 km/h.
It had left Winnipeg and was headed for Thunder Bay.
Investigators found that the surface beneath the track at the accident site consisted of soft, saturated peat in an area with poor drainage.
Their report states that the operation of loaded high-capacity rail cars in the train accelerated the deterioration of "the inherently unstable track subgrade."
In addition, railway inspection procedures and technologies based on surface observations are unable to measure underlying subgrade conditions, "increasing the risk that impending subgrade failure will go undetected."
The TSB said that following the accident, CP improved the track infrastructure in the derailment area to reduce the risk of a similar incident happening again.