Broken wheel led to January 2016 derailment near Webster, Ontario
Winnipeg, Manitoba, 29 March 2017 – In the release of its investigation report (R16W0004) today, the Transportation Safety Board of Canada (TSB) determined that a broken wheel, caused by a service-related failure, led to the January 2016 derailment of a Canadian National Railway Company (CN) freight train near Webster, Ontario.
On 9 January 2016, a CN freight train proceeding westward on the Redditt Subdivision experienced a train-initiated emergency brake application at Mile 21.74, near Webster, Ontario. A total of 26 cars had derailed, including six Class 111 residue tank cars that last contained diesel fuel. There were no injuries and no product was released.
The investigation revealed that a progressive fracture on a wheel of the second car from the head end eventually allowed the wheel to move inboard on the axle and derail. The train proceeded on the track for approximately eight more miles before cars derailed, setting off the train-initiated emergency brake application.
The investigation determined that about 14 minutes prior to the accident, the train passed a wayside inspection system (WIS) where a wheel impact load detector (WILD) recorded the impact load of the defective wheel. While the reading exceeded the Association of American Railroads (AAR) condemning limits, CN WILD guidelines permitted the wheel to remain in service without restriction until it reached its certified car inspection location. The development and implementation of WILD technology has been an industry initiative to enhance rail safety by proactively identifying wheels with defects that can cause derailments or damage to track infrastructure. However, if railway WILD guidelines do not provide adequate guidance for dealing with wheel impacts that are condemnable under AAR rules, there is an increased risk that wheels with emerging defects will not be identified and removed from service before progressing to failure.
In response to a 2011 TSB Rail Safety Advisory, Transport Canada (TC) had indicated that it would create a joint TC-industry forum to conduct a comprehensive review of WIS and WILD criteria. However, there has not been any progress by TC relating to guidelines, standards or rules for the use of WILD technology. In the absence of WILD condemning limits within the TC-approved Railway Freight Car Inspection and Safety Rules and/or other related TC guidance, WILD company guidelines may not be sufficiently robust to consistently protect against wheel failures.
See the investigation page for more information.
The TSB is an independent agency that investigates air, marine, pipeline, and rail 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.
For more information, contact:
Transportation Safety Board of Canada
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