A number of small problems came together to cause 10 empty CP Rail tank cars to jump the tracks near Bowden last year.
This was the finding of a Transportation Safety Board of Canada investigation of an incident that occurred on April 21, 2012, seven km north of Bowden where the railway track runs parallel to Hwy 2.
It involved 10 cars of an 80-railcar northbound freight train derailing at a switch in the tracks. Two of the cars then smashed into the lead locomotive of another CP rail freight train that had been sitting on another track.
One derailed tank car also leaked a small amount of glycol — residue of the load the car had previously been carrying — but there were no injuries.
The Transportation Safety Board investigation found that a combination of track and railcar defects, combined with the grade at the derailment site, were sufficient to cause the wheels of light, empty rail cars to skip the tracks.
“Each of these factors alone would not have resulted in the derailment,” the report concluded, but the combined factors were enough to derail two rail cars, which then dragged more cars off the track.
The incident occurred at a siding switch, when wheels on the 12th and 13th cars climbed the rail at the turnout.
A grade change at the site, “track geometric irregularities,” and a slight (one and a quarter inch) mismatch in the coupler height between the 12th and 13th railcars were among the defects found.
“With the train navigating the turnout, the cars were in the jackknifing position,” stated the report. This resulted in force against the rail.
The 12th and 13th cars were also found to have dry and un-lubricated centre plates that didn’t allow the wheels to pivot fully on the first two derailed tank cars.
“These types of defects can affect car body movement on curved track and lead to increased lateral forces,” states the report.
CP Rail spokesperson Ed Greenberg said the Transportation Safety Board findings, along with information obtained from CP Rail’s own internal investigation, are being used to make safety improvements.
“We have already taken some corrective actions,” said Greenberg, including installing more monitors along the track that detect problems with train performance. “We’ve embraced the technical train inspections system.”
Such incidents lead to a “heightened awareness for our teams” about the need for visual and electronic inspections, he added.
“We are always interested in strengthening our operations when it comes to safety.”
The Transportation Safety Board investigation does not attribute fault or liability, but is done to improve transportation safety.
lmichelin@www.reddeeradvocate.com