Flawed Rail Caused CN Derailment

In follow up to an October 21, 2011 Canadian National Railway train derailment near Alix Junction, Alberta,  the Transportation Safety Board (TSB) of Canada has recently called for more stringent rail flaw testing (see this TSB Investigation Report).

The CN freight train was over 2 miles long and consisted of 3 locomotives and 87 loaded rail cars. Seven double-stack intermodal flat cars derailed about 5,770 feet behind the locomotives when a “sudden catastrophic failure of the high rail occurred, likely due to an existing, transverse defect in the rail.” The derailed cars were loaded with a variety of products, including dangerous goods. About 900 litres of phosphoric acid were spilled and 470 feet of track were destroyed.

The TSB report goes on to say CN’s ultrasonic rail tests did not identify all the transverse defects in the older vintage rail, and when older vintage rail remains in track, the number of rail fatigue defects will continue to increase and result in increased rail failure. Since this derailment, track safety rules have been revised to increase the mandatory requirement for rail flaw testing. The TSB report concludes with, “Despite advances in ultrasonic testing technology, the timely detection of all internal rail defects continues to be problematic.”

(In the past, the TSB has criticized CN for running too long and heavy trains on its tracks, which contributes to the increasing number of derailments.)

~ by railroaded on September 29, 2012.