The track had not been inspected for weeks. Heavy haul causes infrastructure to deteriorate faster than anyone can imagine. Analysis of the causes of train accidents is critical for rational allocation of resources to reduce accident occurrence in the most cost-effective manner possible. In the last decade, 15%
of all train derailments in the world were caused by broken rail or weld !
Statistics show that an average of 8 rail cars fall off the track every time there is a derailment. If cost differ from a railroad environment to another in the world, one thing cannot be pushed aside, costs for bringing things back to normal operations are immense.
Derailments risks reduction programs are cheaper than repairing.
In a time of money talks everything, even more in a context of economic worries, managers have to decide often between the”Don’t fix it rule if it works” and the implementation of quality control of the infrastructure that commands immediate investments for longer term rewards.
Meanwhile, analysis establishes a direct relationship between frequency and severity of derailments.
Accounting for severity is important because derailments in which more cars are involved are likely to be more damaging and more costly, have a greater likelihood of involving a hazardous materials car if any are in the consist, and if derailed, they are more likely to suffer a release. Accident severity is affected by a variety of factors, including train length, derailment speed, point of derailment (POD-the position of the first car in the train that is derailed).
Studies not only confirm that broken rails and welds are the most frequent factors for derailment causes but they also state that they represent 23% of all cars derailed.
Each car that derails costs money and time.
In fact, these derailments present an average of 13 cars pushed off the track which represents 63% more than what the average derailment causes.
More train derailments are caused by a broken rail or weld, those happen on the main line at greater speeds so more cars do fall off the track raising the costs and hazards. Frequency and severity meet.
Main-line derailments are so particularly damaging because of the high speeds and long consists. The greater mass and speed mean that the force and potential impact in regard to property damage, casualties, and environmental effects are all correspondingly greater.
At derailment speeds above 25 mph, main causes are quasi only equipment related. They are broken rails or welds but also in a subsidiary manner they are bearing failure, broken wheel, and axle and journal defects.
Consequently, efforts to prevent these high-frequency, high-severity accidents should receive considerable attention.
Implementation costs of different risk reduction measures may be affected by the effectiveness of technology, extent of implementation, installation and maintenance practices, and many other factors.
However, to give a practical idea of investments needed, financial data suggests that ultrasonic inspection programs present an average of 900 $US per mile, grinding and mechanical repair programs are at 1 900 $US per mile.
Finally, since broken rails and welds account for twice as much as any other factor in derailments, any inspection program that will result in a 50% reduction rate will work better than any other factor reduction working at 100% !