Transportation Safety Board of Canada

Transportation Safety Board of Canada

November 16, 2006 12:00 ET

The Transportation Safety Board of Canada Establishes a Relationship Between Secondary Main-Line Derailments and Bulk Tonnage Traffic

GATINEAU, QUEBEC--(CCNMatthews - Nov. 16, 2006) - The Transportation Safety Board of Canada (TSB) today released its Safety Issues Investigation Report (SII R05-01) that establishes a relationship between secondary main-line derailments and bulk tonnage traffic.

In the winter of 2003-2004, a series of train derailments on secondary main lines in western Canada involving broken rails prompted the TSB to initiate a safety issues investigation (SII). To develop an understanding of the factors underlying these occurrences, the investigation examined the commonalities among these occurrences, reviewed relevant TSB data, and used data provided by the railways to test a specific hypothesis - that bulk tonnage traffic, independent of cumulative tonnage, is associated with increased derailment risk due to rail defects.

The SII reveals that a statistically significant relationship exists between the incidence of rail defects and the level of bulk tonnage traffic. Where rail weight is less than 130 pounds, increased bulk unit train tonnage significantly increases rail defects, resulting in a higher risk of broken rail derailments. Risks related to the problems in balancing track maintenance and degradation to the comprehensiveness of the Railway Track Safety Rules and to deficiencies in rail inspection capabilities and maintenance practices were identified.

The quantitative analysis was conducted only on Canadian Pacific Railway (CPR) subdivision data because an insufficient number of Canadian National (CN) subdivisions met the specific selection criteria to furnish a sample of sufficient size to perform a similar analysis.

An SII reviews multiple occurrences that the Board suspects have similar underlying factors. The overall significance of secondary main-line derailments and identification of the relationship to bulk tonnage traffic would have been less likely through individual occurrence investigations.

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.

This communique is available on the TSB Web site at

Contact Information

  • Transportation Safety Board of Canada
    John Cottreau
    Senior Media Relations Advisor
    613-292-4146 (cell)
    Transportation Safety Board of Canada
    Genevieve Lamarche
    Media Relations Specialist
    613-290-9875 (cell)