Canada has had its fair share of crude oil unit train derailments in recent years. TSB has completed its report on the latest incident
Canada’s Transportation Safety Board (TSB) has identified a poorly repaired rail as being the immediate cause of the derailment of a Canadian Pacific (CP) crude oil train in Saskatchewan in February 2020. The incident led to 32 DOT-117J tank cars leaving the tracks, thirty of which released product. Some 1.75m litres of crude oil spilled, leading to a fire. Highway 16, which runs alongside the tracks, was closed and 85 residents of the nearby town of Guernsey evacuated.
The 104-car train, with two head-end locomotives, a tail-end locomotive and two buffer cars behind the head-end locomotives, had departed from Rosyth, Alberta and had been parked overnight at the Sutherland Yard in Saskatoon before heading for Noyes, Minnesota via Winnipeg. About two hours after leaving Sutherland, while heading east at 44 mph (71 kph) a train-initiated emergency brake application occurred while the head end of the train was passing over a crossing; the crew saw a large fire already burning behind them and called the controller, before uncoupling the two locos from the rest of the train and moving them to a safe location.
TSB recorded the final position of all the derailed tank cars, identifying that the central section, comprising 23 cars, where the derailed cars jack-knifed, contained the largest amount of damage and tank breaches.
HOW AND WHY
In such events, the task of the investigator is two-fold: firstly, to determine why the train went off the tracks and, secondly, to investigate how well (or not) the tanks themselves behaved under crash conditions.
In the Guernsey event, the first of these was fairly easy to resolve. The month before the accident, engineers had replaced some sections of rail in the Sutherland Subdivision, using ‘plug rail’ inserts – short lengths of pre-used rail that are dropped into replace broken or damaged rail. In this case, TSB identified the section of plug rail that had failed, causing the derailment, and noted that it had not been properly certified nor well installed – the replacement work was carried out in dark, windy and freezing conditions.
As to the tank cars themselves, TSB says the train speed, the number of derailed tank cars and some of the tank car damage were similar to other major accidents involving crude oil unit trains that it has investigated. However, it was unable to determine precisely how each tank car involved in the Guernsey derailment had performed; many tanks lost part or all of their contents, causing at least two major pool fires, which caused further damage. In addition, a number of derailed tank cars had to be moved by heavy equipment in order to allow fire crews to get into position and this caused further damage, as well as further loss of product.
More importantly, perhaps, TSB notes that a very similar accident had occurred in the same Sutherland Subdivision, only 5 miles (8 km) away from the Guernsey derailment, just two months earlier. This too involved a crude oil unit train of similar length, moving at similar speed and with post-derailment fires. As such, TSB has made recommendations both to CP and to Transport Canada (TC).
TSB issued a Rail Safety Advisory suggesting that operators should modify key train speeds, taking into account various risks. It also noted that TC’s Track Safety Rules have not been updated since May 2012 and lack any assessment of the need for enhanced track standards for key routes; TSB recommended that TC look at revising the Riles. Several Ministerial Orders were also issued, requiring train operators to review their practices.
CP has also implemented its own wayside system for the detection of track discontinuities in non-signalled territory. The system can detect broken rails and indicate the presence of trains. It works by sending a low-voltage signal through the rails and relies on technology found in other industries, such as solar cells, lithium ion batteries, and miniaturised signal-processing circuits.
source: https://hcblive.com/rail-fire-in-the-snow/
