Nipigon Ontario - In its Investigation Report R15H0005 released today, the Transportation Safety Board of Canada (TSB) determined that the complete failure of an already-cracked rail led to the January 2015 derailment of a Canadian Pacific Railway (CP) freight train that was carrying dangerous goods near Nipigon, Ontario.
 
This investigation also made findings about the performance of pressure tank cars during derailments and the risks to train crews when dangerous products are released.
 
On 13 Jan 2015 a CP freight train was proceeding eastward on the Nipigon Subdivision when it derailed 21 cars, including seven dangerous goods tank cars loaded with propane, near the Dublin siding, approximately 34 kilometres east of Nipigon.
 
As a result of the derailment, one tank car lost its entire load of propane and another tank car loaded with propane released product.
 
One crew member sustained minor inhalation injuries due to exposure to propane.
 
The investigation determined that rail within a joint failed catastrophically as the train passed over it, leading to the derailment of the 11th to 31st cars.
 
The rail failure originated at a bolt hole crack within a joint in the south rail which had propagated diagonally downward through the base of the rail likely due to one or more elevated wheel impacts that occurred prior to the arrival of the occurrence train.
 
Despite regular inspections, the rail defect was not detected because the bolt hole crack and the rail base fracture were behind the joint bars which made visual detection difficult, especially in the winter months when snow covered the rail base.
 
The cold temperature at the time of the accident also made the rail more susceptible to brittle failure.
 
Despite the conductor's repeated exposure to the propane, medical assistance was not specifically requested until two hours later.
 
The investigation found that CP training, procedures, and guidelines were insufficient to protect the conductor from the hazards associated with the derailment and release of a large volume of propane while conducting the site assessment.
 
A number of deficiencies posed additional risk in this occurrence, particularly with respect to the lack of information available to crews and rail traffic controllers about the risk of ignition and the health hazards posed by products involved in a derailment.
 
Although five of the six tank cars generally performed as intended, this derailment demonstrated that even a DOT-112 pressure tank car with improved design can be vulnerable to releasing product when exposed to high impact forces and sharp impact punctures.
 
The TSB is an independent agency that investigates marine, pipeline, railway, and aviation 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.
 
Anonymous Author.