Backgrounder (R19W0002)

Findings from TSB investigation R19W0002 – January 2019 main track train collision and derailment near Portage la Prairie, Manitoba

Investigations conducted by the Transportation Safety Board of Canada (TSB) are complex since an accident rarely results from a single cause. In the case of the January 2019 main track train collision and derailment involving two Canadian National Railway (CN) freight trains near Portage la Prairie, Manitoba, several factors led to the accident. The 10 findings below detail the causes and contributing factors that led to this occurrence. Additionally during the course of the investigation, the TSB also made five findings as to risk and five other findings.

Findings as to causes and contributing factors

These are conditions, acts or safety deficiencies that were found to have caused or contributed to this occurrence.

  1. The collision occurred as eastbound Canadian National Railway Company (CN) train M31851-01 (train 318), operating on the south track of the CN Rivers Subdivision, went past Controlled Signal 504S at Mile 50.4, which displayed a Stop indication, and struck the 95th to 102nd cars of westbound CN train M31541-03 (train 315). Train 315 was on the north track where it transitions to double main track and was exiting the equilateral turnout at Mile 50.37 when the accident occurred.
  2. As a result of the collision, the 2 lead head-end locomotives on train 318 and 8 cars on train 315 sustained damage and derailed.
  3. After the train 318 crew overheard the radio conversation between the rail traffic controller and train Q11651-30 (train 116) crew, the train 318 crew expected to continue to follow train 116 to Winnipeg without stopping.
  4. The train crew did not respond to the Advance Signal 522S Clear to Stop indication, and operated on a restrictive signal for 6389 feet with Trip Optimizer engaged and without slowing down.
  5. The locomotive engineer assumed manual control from Trip Optimizer and made a full service brake application with insufficient distance to be able to stop the train before Signal 504S and to avoid the collision using the selected braking technique.
  6. The locomotive engineer’s mental model of the situation and expectation of how the situation would unfold contributed to a delayed reaction to the restrictive signal indication displayed at Advance Signal 522S (Mile 52.2).
  7. The locomotive engineer was fatigued due to acute sleep disruption brought on by abbreviated and disrupted sleep periods during the 2 nights preceding the accident. As a result, at the time of the occurrence, he was likely experiencing a performance decrement that contributed to the delayed reaction in responding to restrictive Signal 522S.
  8. It is likely that the low workload associated with operating train 318 using Trip Optimizer, together with fatigue, reduced the locomotive engineer’s arousal levels and impacted his ability to maintain vigilance and situational awareness.
  9. Due to the inexperience of the train 318 conductor and the authority gradient that existed between the crew members, the conductor deferred to the locomotive engineer without questioning the operation of the train and, as a result, the crew’s actions to slow and stop the train before Controlled Signal 504S were delayed and ineffective.
  10. In the absence of a physical defence such as an enhanced train control system, there was no automatic intervention to slow or stop the train when the crew did not initially respond to the Clear to Stop signal displayed in the field.

Findings as to risk

These are conditions, unsafe acts or safety deficiencies that were found not to be a factor in this occurrence but could have adverse consequences in future occurrences.

  1. Despite the administrative defences provided by the Work/Rest Rules for Railway Operating Employees and fatigue management guidelines, as well as railway company scheduling practices and fatigue management plans, operating employees continue to be negatively influenced by fatigue, increasing the risk of accidents occurring.
  2. If operating crew members do not receive enhanced initial and recurrent crew resource management training to develop skills in crew communication, the coordination of decision making and activities, and dealing with authority gradients that may exist within a locomotive cab environment, there is an increased risk that inadequate crew communication will lead to unsafe operations.
  3. If the Canadian railway industry continues to rely solely on administrative defences, such as company procedural guidelines, the Canadian Rail Operating Rules, or the Work/Rest Rules for Railway Operating Employees, to protect against train crews not responding appropriately to signal indications displayed in the field, there is a continuing risk of train accidents and incidents occurring.
  4. If a train accident occurs on a key route, a key train, or trains, may be involved, increasing the risk of a dangerous goods release and adverse consequences to people, property or the environment.
  5. If Transport Canada and the railway industry do not take action to implement physical fail-safe defences to reduce the consequences of inevitable human errors, the risk of collisions and derailments will persist, with a commensurate increase in risk on key routes in Canada.

Other findings

These items could enhance safety, resolve an issue of controversy, or provide a data point for future safety studies.

  1. The distance of 9504 feet between Advance Signal 522S and Controlled Signal 504S was sufficient to safely stop train 318 using the locomotive engineer’s selected method of a full service brake application.
  2. An emergency brake applied from both the lead locomotive and the end-of-train unit would have been sufficient to bring the train to a stop 2316 feet before Signal 504S.
  3. Placing the automatic brake handle into the suppression position while the train was moving did not provide any additional braking force compared to a full service brake application, and further increased the estimated stopping distance compared to an emergency brake application.
  4. The train 318 locomotive engineer and conductor were at risk of fatigue-related performance decrements in the weeks preceding the occurrence due to circadian rhythm desynchronization as a result of variability in shift start and end times.
  5. Class 1 railways that operate in the United States (U.S.) have implemented positive train control on the trackage required by U.S. legislation, which also provides a physical fail-safe defence against operating crew errors that are influenced by fatigue.