Cracked, worn railhead behind 27-car derailment near Silton, Sask., in October 2021

More than two dozen train cars that derailed almost two-and-a-halfyears agoabout 50 kilometres north of Reginatoppled because of a broken rail, according to a report from the Transportation Safety Board.

A portion of a Canadian Pacific Railway freight train traveling with 200 potash-filled freight cars derailed near Silton, Sask., around 5 a.m. on Oct.16, 2021.

Pre-existing fatigue cracks had spread to the base of the rail in a sudden overstress as the train passed over it,the report states.

The Transportation Safety Board says the track had been tested for defects more frequently than the mandate to do so. However undetected, pre-existing fatigue cracks caused the rail to break when the train passed over it.

The railway has since implemented a detector system on the tracks in the area to send automatic alerts about any broken rail, rail gap, or loose joints.

The notifications provide warnings that allow the operations centre to stop a train before it encounters any track discontinuities in non-signaled territory.