Improperly torqued bolts caused Ottawa LRT derailment

Improperly torqued bolts caused the derailment that has shut Ottawa’s LRT system down for more than a month, the city’s transit commission heard Wednesday.

The new information shows it was a maintenance problem that led to the Sept. 19 derailment near Tremblay Station, rather than a technical or design issue.

And it led some transit commissioners to question why such a seemingly small mistake could shut down the entire Confederation Line for several weeks.

The investigation into the root cause of the Sept. 19 derailment, which damaged the train and several hundred metres of track, continues.

But LRT contractor Rideau Transit Group and train manufacturer Alstom have confirmed that improperly torqued bolts on the gearbox were the primary cause of the derailment.