The Transportation Safety Board of Canada has concluded its investigation into the derailment of a Canadian Pacific Railway freight train in October of 2021 near Silton, which is about 50 kilometres northwest of Regina. Twenty-seven freight cars derailed into a large pile and many breached, spilling out potash. A news release from the TSB says there were no injuries.
It was determined the trail derailed when the west rail broke from pre-existing fatigue cracks that had spread down the base of the rail, so it was overstressed as the train passed over it. The frequency of rail flaw detection testing on the Lanigan Subdivision exceeded regulatory requirements. In fact, testing was performed shortly before the accident with no rail defects identified. The TSB says accuracy is limited by current technology, rail surface conditions and the size and type of defects.
On July 29th of 2022, nine months after the accident, CP implemented a non-vital rail integrity detector on the Lanigan Subdivision, which sends automatic notifications if something like a broken rail or loose joint is detected.