Rail transportation safety investigation R20H0079

Updated in September 2020: This investigation is in the report phase.

Table of contents

Rolling stock damage without derailment

Ottawa Light Rail Transit

The occurrence

On 2 July 2020, during maintenance activities, cracks were found on the outboard face of the wheel hub of two resilient wheels that were secured to an axle by bolts in a bogie (truck) from Ottawa Light Rail Transit (OLRT) Light Rail Vehicle (LRV) 1113. The incident was reported to the Transportation Safety Board of Canada (TSB), which opened an investigation (R20H0079).

What we know

  • On 3 July 2020, during a daily inspection implemented following the detection of the first cracked wheel hub, another cracked wheel hub was found on LRV 1108.
  • Alstom, the LRV builder, immediately issued a safety alert and, in conjunction with OLRT, implemented a daily inspection of each LRV wheel before the LRV was permitted to enter service. The inspections subsequently identified four additional wheels with cracks observed in the outboard surface of the wheel hub.
  • Concurrently, the preliminary analysis performed by Alstom suggested that the jacking screws protruding from the rear surface of the wheel hub may have contributed to the development of the wheel hub cracks.
  • A total of four bogies identified with cracked wheels were sent to the TSB laboratory for a teardown examination. During TSB teardown examination of two of the bogies:
    • two additional cracked wheels that were previously unreported were identified, and
    • two cracks not previously identified were visually obscured by a grounding cable positioned in front of the corresponding jacking screw.
  • A total of eight resilient wheels with cracked hubs have now been identified and removed from service on the OLRT LRV fleet. 
  • The detailed daily inspection process is ongoing for all OLRT LRVs that are still equipped with wheels that have jacking screws applied.  

Next steps

  • The TSB investigation continues with two additional bogie teardowns, wheel material evaluation, failure analysis of all wheels in which cracks are identified as well as a review of maintenance activities and other potential influences. The investigation will also look into other possible contributing factors.    

Identification of safety deficiencies

Investigations are complex, and the TSB takes the time needed to complete a thorough investigation. However, should the investigation team uncover safety deficiencies that present an immediate risk, the Board will communicate them without delay.


Safety Communications


Media materials

Investigation notice

2020-07-10

TSB launches investigation into wheel cracks on Ottawa Light Rail Transit vehicles

Gatineau, Québec, 10 July 2020 — The Transportation Safety Board of Canada (TSB) is conducting a class 3 investigation after cracks were found on a total of four wheels on three separate Ottawa Light Rail Transit (OLRT) vehicles during maintenance and inspection activities.


Investigation information



Investigator-in-charge

Photo of Rob Johnston

Mr. Rob Johnston has been with the Transportation Safety Board of Canada (TSB) since 2001. He was Senior Regional Investigator in Winnipeg until 2004, when he assumed the position of Senior Investigator, Standards and Training Officer at TSB Head Office in Gatineau, Quebec. He became Manager of Central Regional Operations in November 2009, and served as Acting Director of Investigations - Rail/Pipeline for 9 months in 2010– 2011.

He now manages a staff of 6 rail/pipeline investigators in Winnipeg, Toronto, and Ottawa, and is responsible for all activities related to rail investigations in TSB’s Central Region, which extends from Cornwall, Ontario, to near the Alberta–Saskatchewan border.

During his time at the TSB, Mr. Johnston has been involved in over 100 TSB accident investigations including 14 major investigations as either an Investigator-in-Charge or as an investigation team member providing technical expertise.

Before joining the TSB, Mr. Johnston worked for Canadian Pacific Railway in Winnipeg from 1984 until 2001, where, as a member of the Train Accident Prevention group, he acquired an extensive background in mechanical operations, failure analysis, and dangerous goods.


Class of investigation

This is a class 3 investigation. These investigations analyze a small number of safety issues, and may result in recommendations. Class 3 investigations are generally completed within 450 days. For more information, see the Policy on Occurrence Classification.

TSB investigation process

There are 3 phases to a TSB investigation

  1. Field phase: a team of investigators examines the occurrence site and wreckage, interviews witnesses and collects pertinent information.
  2. Examination and analysis phase: the TSB reviews pertinent records, tests components of the wreckage in the lab, determines the sequence of events and identifies safety deficiencies. When safety deficiencies are suspected or confirmed, the TSB advises the appropriate authority without waiting until publication of the final report.
  3. Report phase: a confidential draft report is approved by the Board and sent to persons and corporations who are directly concerned by the report. They then have the opportunity to dispute or correct information they believe to be incorrect. The Board considers all representations before approving the final report, which is subsequently released to the public.

For more information, see our Investigation process page.

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.

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