Freight

TSB says rail fractures, undetected rail defects led to 2013 Alberta derailment

In its investigation report, the Transportation Safety Board of Canada (TSB) determined that numerous rail fractures led to the October 2013 derailment and fire involving a Canadian National (CN) train in Gainford, Alberta.

On October 19, 2013, a CN freight train, travelling from Edmonton, Alberta, to Vancouver, British Columbia, derailed 13 cars, including four DOT 111 tank cars containing petroleum crude oil and nine DOT 112 tank cars containing liquefied petroleum gas (LPG) in the siding at Gainford, Alberta. Two LPG tank cars were breached during the derailment and caught fire and a third LPG car released product from its safety valve which ignited. About 600 feet of track was destroyed and a house located directly north of the derailment site was damaged by the fire.

The investigation determined that the train derailed when one or more rail breaks occurred in the high rail as the train travelled through the curve in the Gainford siding. TSB said numerous defects were found along the length of the high rail in the curve. A rail-flaw detection test through the area two months earlier had not identified these defects. In March 2013, the low rail had been replaced with a new rail that reduced the curve’s superelevation. TSB noted that in this situation, more stress was placed on the high rail, increasing the risk of rail defect development and failure.

One of the DOT 112 tank cars carrying LPG was punctured in the underside by the coupler from another car. This caused it to release its load and explode. None of the DOT 111 tank cars, which were built to the CPC-1232 standard, released petroleum crude oil, as the cars derailed in a line on their sides and did not suffer secondary impacts.

Following the occurrence, CN conducted walking inspections and rail-flaw detection re-testing on all 25 mph sidings. Speed was reduced to 15 mph in these sidings until they were retested. Rail grinding within these sidings was also programmed to remove rail surface defects.