A Transportation Safety Board investigation found that an axle had broken in a Saskatchewan train derailment last year.

On Sept. 26, 2018, a 41-car Canadian National Railway train travelling westward derailed near Landis. No one was hurt and no dangerous goods were involved.

Investigators noted that the first hopper car to derail was missing an axle and wheels; the broken axle was found north of the track, about 91 metres from the east switch for the Landis Producer Co-op track.

A metallurgical analysis indicated that the failure was likely caused by surface damage sustained by the axle, which may have caused by a defective indexer - a mechanical system used to move rail cars - at a customer loading facility, the report says.

Although rail cars regularly receive the required certified car inspections, a cracked or damaged axle may not be identified through such visual inspections, depending on the size and location of the defect, the report says. Also, according to the TSB report, cracked axles are often difficult to identify because automated detectors located on train tracks are not necessarily designed to identify a rail car with a cracked axle.

CN is implementing and issuing guidance to its customer facilities for the inspection and maintenance of indexers to prevent axle damage, the report says.