Canada's TSB cites broken rail in 2019 derailment of CP crude oil train

The Transportation Safety Board of Canada (TSB) recently released its investigation report of a 2019 derailment of a Canadian Pacific freight train near Guernsey, Saskatchewan, which resulted in the release of 468,000 gallons of crude oil.

The accident occurred Dec. 9, 2019, as a CP crude oil unit train was traveling 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 TSB report states.

TSB's 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, TSB reported.

Although the train was operated in accordance with the federal "Rules Respecting Key Trains and Key Routes" in place at the time, 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, according to the TSB.

After this accident and a second serious CP crude oil unit train derailment that occurred Feb. 6, 2020, near Guernsey, the TSB issued rail safety advisories to Transport Canada. In response, TC instructed the rail industry to revise those rules as well as the "Rules Respecting Track Safety." Since then, the rules have been revised to include a number of safety improvements related to the operation of key trains and the inspection and maintenance of track structure.

Moreover, CP implemented safety measures, including a wayside system for detecting rail breaks in non-signaled territory, such as the Sutherland Subdivision, increased its number of autonomous track-geometry measuring systems and upgraded the track infrastructure on the subdivision, according to TSB's report.