News release

TSB releases investigation report into September 2016 collision and derailment involving two trains in Calgary, Alberta

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In its investigation report (R16C0065) released today, the Transportation Safety Board of Canada (TSB) determined that train control decisions based upon inaccurate assumptions led to the September 2016 collision and derailment involving two Canadian Pacific Railway (CP) trains in Calgary, Alberta.

On 3 September 2016, westbound train 303 collided with the tail end of train 113, which was stopped on a non-main track near Alyth Yard in Calgary. Two locomotives on the head end of train 303 and two of its hopper cars derailed. The last car on train 113 also derailed. There were no injuries and no dangerous goods were released.

The investigation found that the collision occurred when train 303 was unable to stop despite applying emergency brakes when the tail end of train 113 came into view. Train 303 had been instructed to follow train 113 into the non-main track when arriving at Alyth Yard. The locomotive engineer overheard parts of a radio conversation that led him to believe that train 113 was undergoing a passing inspection three miles further west. This belief was reinforced when train 303 was not held at Glenmore, about a mile to the east of where the main track ends before entering Alyth Yard, which was normal practice when a preceding train was delayed.

The investigation also found that train 303 entered the non-main track at 36 mph, too fast for the heavy unit train to stop within half the range of vision, as required. The maximum track speed at this location was 45 mph, instead of the usual 15 mph for non-main tracks. Following a track reconfiguration in 2013, CP had changed the method of train control in the area from centralized traffic control to non-main track, but without reducing the maximum track speed. At the time of this operational change, a risk assessment was not mandatory. However, current regulations would require a risk assessment. If risk assessments are not conducted for changes to railway operations, potential hazards may not be identified and appropriately mitigated, increasing the risk of accidents. Safety management and oversight is on the TSB Watchlist of key issues to be addressed to make Canada's transportation system even more secure.

Following the occurrence, CP reduced track speeds in the occurrence area. By December 2016, it had reinstalled centralized traffic control in the area.


The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.

For more information, contact:
Transportation Safety Board of Canada
Media Relations
Telephone: 819-360-4376
Email: media@tsb.gc.ca