On the morning of 20 April 2017, a cut of 11 cars loaded with logs rolled uncontrolled out of the Woss Reload Centre, operated by Western Forest Products Inc. (WFP), near Woss, British Columbia. The uncontrolled cars travelled over a derail, and then re-railed at a switch, allowing the cut of cars to depart the Reload Centre and continue down the grade. Shortly thereafter, the uncontrolled movement struck two on-track engineering work equipment vehicles that were occupied by engineering employees. The 11 cars and two work equipment vehicles derailed. Three engineering employees were fatally injured, and two employees were seriously injured.
The investigation found that the uncontrolled movement had separated from the rest of the cars after a knuckle inadvertently released. A previous coupler repair had resulted in the installation of a top-operated locking block into the bottom-operated mechanism. Although this configuration is permissible, the locking block had not dropped fully into place during the coupling. However, the locking block did engage the knuckle tail sufficiently to pass the pull test, and the coupling was deemed secured.
The investigation determined that, when the uncontrolled cut of cars reached the derail, the lead truck of the lead car derailed as intended. However, the derail was damaged by the cars, rendering it ineffective for the remaining wheels. Although the derail installation was compliant with regulatory standards, it had not been installed or maintained to manufacturer and industry standards. In addition, the derail was situated on deteriorated softwood ties in an area of fouled ballast that was inhibiting proper drainage. It is a rare event for rolling stock derailed by a derail to re-rail.
The investigation also determined that emergency procedures, including emergency radio communications, were not practised by the railway. If emergency procedures relating to hazards during switching operations, including radio communication procedures, are not practised on a regular basis, there is an increased risk that the procedures will not be followed in an emergency situation.
Shortly after this occurrence, the TSB issued a rail safety advisory (RSA) to the MOTI relating to the installation, maintenance, and inspection of derails at WFP. In November 2017, WFP announced the closure of the Englewood Railway. At the conclusion of its investigation, the TSB issued an RSA to a number of railway stakeholders, including regulators, railways and railway associations, relating to the use of the visual verification method to ensure couplings are secure.