The Transportation Safety Board of Canada (TSB) released its investigation report into the derailment of a Canadian Pacific Railway Company (CP) freight train near Guernsey, Saskatchewan, which resulted in the release of 1.77 million litres of crude oil.
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On 9 December 2019, a CP crude oil unit train was travelling east on the Sutherland Subdivision when the crew observed a gap in the south rail approaching the Wolverine Road public passive crossing.
As the head-end locomotive traversed the gap, a train-initiated emergency brake application occurred. Shortly after, crew members observed a large explosion behind them as the head-end locomotive and first car separated from the train.
Subsequent inspection determined that 33 cars derailed, of which 20 tank cars had breached, and the released product ignited, resulting in a large pool fire that burned for nearly 24 hours.
There were no injuries, and no evacuation was required.
The investigation determined that the south rail had likely failed under a previous train, causing an undetermined length of rail to break away and separate from the track and expose the rail ends.
The condition of the track components (anchors, ties, and ballast) did not provide adequate resistance to the rail forces initiated by the cold weather at the time of the accident, which contributed to the breaking of the rail.
Despite regular track visual inspections and ultrasonic rail flaw detection testing, which exceeded regulatory requirements, the broken rail went undetected before the arrival of the train.
Although the train was operated in accordance with the Rules Respecting Key Trains and Key Routes in place at the time of the occurrence, the train speed (44 mph) contributed to the number of cars that derailed, breached, and lost their product.
If company risk assessments do not adequately consider increases in traffic tonnage, the use of heavier rail cars, and the potential for more rapidly degrading track structure, regular track maintenance activities may no longer be sufficient to maintain track to the required standards, increasing the risk of track infrastructure failures that lead to rail accidents.
Since this occurrence, CP has implemented a number of safety measures including a wayside system for detecting rail breaks in non-signalled territory, such as the Sutherland Subdivision, increased its number of autonomous track geometry measuring systems, and upgraded the track infrastructure on the Sutherland Subdivision. ■
A strong storm that originated over the Pacific has tracked through the Great Basin and is currently transitioning across the Rockies to redevelop across the central High Plains later today into early Saturday morning.