In January 2019, a railway collision near Copenhagen, Denmark resulted in 8 passenger fatalities and 18 injuries. What got my attention in the post-mortem report were the stated causes of the incident: improper loading, lack of lubrication, improper maintenance, and collision with empty semi-trailer from cargo train. These, however, were NOT the root causes. They were contributing factors. Here’s a brief recap of the story, along with some pertinent details.
At 7:29 a.m. on Jan. 2, 2019, an east-bound passenger train collided with a semi-trailer that was blown off a west-bound freight train flatbed car (called a “pocket wagon”) on the Great Belt Bridge crossing, a 7.5-mile waterway. Both trains were traveling at approximately 75 MPH at the time of the collision.
A summary analysis report (which is said to be an official final report) was published in Jan. 2020. It stated, “The semi-trailer’s kingpin was not locked on to the saddle of the pocket wagon. The fresh gale that blew across the West Bridge when the freight train passed was therefore able to blow the empty semi-trailer out of its position in the pocket wagon. The semi-trailer was then dragged alongside the wagon until the place of collision.”
The saddle with a kingpin locking mechanism is the ONLY anchor point between the semi-trailer and the pocket car. The saddle manufacturer’s knowing this stated in their documentation that non-lubrication of the saddle locking mechanisms and pivot points may be critical to safety.
Railway crews prepare the pocket cars before loading the semi-trailers (loaded and unloaded) with a crane, adjust and lock the trailer kingpin in the saddle. This task includes assuring kingpin locking lever in in the “locked” position by a visual check.
The railway maintenance organization was responsible for performing and documenting safety-critical maintenance on the pocket cars, as well as on other rail cars and equipment. However, the saddle was listed as an “accessory” on the pocket car and not considered “safety critical.”
According to the report, there was no evidence in the railway’s maintenance records that regular inspections, maintenance, nor correct lubrication of the saddle’s locking mechanism was regularly performed according to the manufacturer’s instructions.
The report went on to state, “Crew members working on loading, unloading and repairing of saddles have expressed the view that lubricating the saddle is not viewed or characterized as being critical to safety, and they regarded lubrication as an operational task.”
Unfortunately, the saddle manufacturer appears to have made it impractical to regularly lubricate the saddle locking mechanism. As the report noted “The design of the saddle did not allow effective lubrication with grease at the pivot point for the release lever without disconnecting the saddle. The manufacturer’s manual described lubrication every four months with lithium-based grease. It also placed special emphasis on ‘all parts of the lock mechanism.”
As the report described the situation, the illustration in the manual didn’t indicate any of the movable parts under the saddle plate, “and since these could not be lubricated effectively using grease, lubricating the hole in the kingpin, together with the lock parts fitted inside, could be taken to be sufficient.”
So, what were the real causes of the collision? Click here to learn more about the investigation. Or click here to access a PDF of the cited summary-analysis report.TRR
ABOUT THE AUTHOR
Bob Williamson is a long-time contributor to the people-side of the world-class-maintenance and manufacturing body of knowledge across dozens of industry types. His background in maintenance, machine and tool design, and teaching has positioned his work with over 500 companies and plants, facilities, and equipment-oriented organizations. Contact him directly at 512-800-6031 or [email protected].
Tags: reliability, availability, maintenance, RAM, safety, root-cause analysis, RCA, Great Belt Bridge crossing collision
