TSB: Broken heel block assembly caused CP derailment near Banff

Written by Jenifer Nunez, assistant editor
image description
Heel block assembly on the north rail. The red arrow points to the heel block joint bar.
TSB

In its investigation report, the Transportation Safety Board of Canada (TSB) determined that a broken heel block assembly led to the derailment of a Canadian Pacific train that destroyed the bridge over 40 Mile Creek near Banff, Alberta, on Dec. 26, 2014.

 

Derailed cars loaded with fly ash, soybeans and lentils were breached, spilling product into the waterway. No initial injuries were reported; however, a crew member sought medical attention for fly ash inhalation.

The investigation revealed that the westbound CP train derailed 15 cars at Mile 82.1 on the Laggan Subdivision, when the end of the north switch point rail fractured in the heel block assembly. The heel block assembly had been weakened due to looseness in the joint, occurring over time under train traffic. Although the regular, detailed and visual track inspections were performed in compliance with regulatory and railway requirements, they did not specifically identify the deteriorating condition of the heel block assembly.

The investigation determined that if loose joints cannot be identified in a timely manner, particularly in the vicinity of switches, the resulting relative movement in the joint will increase over time, increasing the risk of cracks in the rail leading to broken-rail derailments. It also highlighted the need for crew members to discuss hazards associated with the commodities carried, prior to, or during, an inspection of derailed cars, in order to address the risk to crew members and other emergency responders.

Following the accident, Transport Canada requested that the railway industry formulate rules with regards to joint bar inspections and repairs in continuous welded rail territory.

 

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