Confusion, speed factors in train crash at Alyth yard: report
Changes in traffic control methods over a stretch of track damaged during the 2013 flood in Calgary contributed to a 2016 freight train collision, the Transportation Safety Board says in a report issued Wednesday.
Just after 9:20 a.m. on Sept. 3, 2016, Canadian Pacific train 303 was rolling westbound into Calgary’s Alyth yard when the 8,000-foot-long train slammed into the rear of the stopped train, toppling a number of cars and sending two derailed locomotives into the dirt along Ogden Road near 50th Avenue S.E.
Nobody was seriously injured in the collision.
According to the report, train 303 had received instructions to enter Alyth yard behind a second train, which had arrived about 30 minutes earlier to swap crews.
Later, the decision was made to delay the first train’s departure to allow another train to depart ahead of it — which the report says was not passed on to 303’s crew.
At about 9:17 a.m., train 303 passed a green signal in Ogden to proceed onto unsignalled track through the yard — “non-main track” that under Canadian rail operating rules requires operation at speeds permitting stopping within one-half of their field of vision, and not exceeding 15 mph.
Radio conversations overheard by 303’s crew, as well as the clear signal they’d just passed, led them to believe the train ahead was several kilometres down the line, prompting the conductor to radio the crew of the train ahead to confirm its position.
The yardmaster replied, saying the train ahead had not yet departed the yard, which prompted 303’s engineer to immediately apply the train’s brakes. But, by then, the train was 330 metres from the stationary train and moving too fast to avoid a collision.
Analysis by the TSB suggests the train needed at least twice that distance to safely come to a stop.
One factor in the collision, the TSB report states, were changes to railway traffic control along the stretch after the 2013 floods.
The June 2013 collapse of the Bonnybrook railway bridge over the flood-swollen Bow River prompted railway officials to take the existing Centralized Traffic Control (CTC) system off-line, redesignating the nearly five-kilometre section as “non-main track” while carrying out repairs.
Once repairs were complete, the stretch retained its designation as non-main track while maintaining its previous speed limit of 45 mph.
Under CTC rules, indications by trackside signal lights convey information about the track ahead — specifically if occupied by another train. The report suggests the crew’s observation of a green signal at Ogden may have misled them about the track ahead being clear — the signal’s authority ended at a small “block end” sign 15 metres away.