Uncontrolled movement of rolling stock related to TSB investigation report (R16T0111)

Uncontrolled movement of rolling stock related to TSB investigation report (R16T0111)

The occurrence

On 17 June 2016, a Canadian National Railway (CN) crew was performing switching operations using a remote control locomotive system (known as a Beltpack) in MacMillan Yard, located in Vaughan, near Toronto, Ontario. The crew was pulling 72 loaded cars and 2 empty cars southward from the yard toward the York 3 main track, in order to clear the switch at the south end of the Halton outbound track, when it lost control of the cars. The group of cars rolled uncontrolled for about 3 miles, reaching almost 30 mph before coming to a stop. There were no injuries. There was no release of dangerous goods and no derailment.

Causes and consequences of uncontrolled movements of rolling stock

Uncontrolled movements generally fall into one of three causal categories:

1. Loss of control: When a car, a cut of cars, or a train is left standing while attended, and available air brakes or locomotive systems cannot prevent it from rolling away, or a locomotive engineer or a Beltpack operator cannot control it using the available air brakes.
2. Switching without air: When a movement is switching with the use of the locomotive independent brakes only (i.e., no air brakes are available on the cars being switched). When an uncontrolled movement occurs, this can result in the cars exiting a yard, siding or customer track, and entering the main track.
3. Securement: When a car, a cut of cars, or a train is left unattended and begins to roll away uncontrolled, usually because
   • no hand brake has been applied or insufficient hand brakes have been applied;
   • a car (or cars) is equipped with faulty or ineffective hand brakes; and/or
   • the train air brakes release for various reasons.

Since 1994, in addition to this one, the TSB has investigated 29 occurrences that involved uncontrolled movements (see Appendix F of the investigation report). The most significant of these occurrences was the 2013 Lac-Mégantic accident.

As a result of the Lac-Mégantic investigation, the Board recommended that Transport Canada require Canadian railways to put in place additional physical defences to prevent runaway equipment (R14-04). In March 2018, following an investigation into an uncontrolled movement at Sutherland Yard in Saskatoon (R16W0074), the Board issued a concern that current defences are not sufficient to reduce the number of uncontrolled train movements and improve safety.

Although not all uncontrolled movements have such major consequences, any uncontrolled movement that affects the main track, although low in frequency, is considered a high-risk event. Uncontrolled movements that affect the main track will typically present the greatest risk of adverse outcomes, particularly if dangerous goods (DG) are involved. In this occurrence, 74 cars, 72 of them loaded (including one DG), and 2 locomotives ran uncontrolled for 3 miles onto the main line of the York Subdivision in Vaughan, reaching a speed of almost 30 mph.

Some statistics

In Canada, over the past 10 years, there were 541 occurrences involving uncontrolled movements. The breakdown below shows that: 4% (21) were caused by loss of control, as was the case in this occurrence; a further 32% (175) were directly related to switching operations without air brakes; and 64% (345) were due to lack of securement. Of the total uncontrolled movements, 11% (61) affected the main track creating a risk to the public or a risk of collision with another train.

As depicted in the figure below, the number of uncontrolled movements in Canada has continued to rise over the past 10 years, with the most recent five-year average (59.8) of uncontrolled movements about 10% higher than the ten-year average (54.1).

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Section 1.20 of the investigation report provides more detailed data and additional information.