Interface - The Journal of Wheel/Rail Interaction

REDUCING DERAILMENTS

Reducing Broken Rail Derailments in Dark Territory
(Part 1 of 2)
By Norman Hooper • January, 2008

This article reflects observations made while serving as Chief Engineer of BC Rail, a Class II railway (now owned by Canadian National) during a period in which the railway reduced service failures and broken rail derailments in dark territory by 60% — an improvement owing to treating the wheel/rail interface as a system, and better managing the risks.

It was four days after Christmas, and the phone rang again. The initial report said that the crew had felt “a bang” on the head-end, then the air dumped before the train got over the spot. An inspection revealed that a rail had broken into seven pieces. Transverse defects (TDs) ranging from small to large were clearly visible. There was double-batter on a couple of the breaks, indicating that the rail had broken up and remained in track as traffic in both directions had gone over it.

In CTC territory, the railway would have been alerted to the failure by the signal system, which is sensitive to broken rails. In signal-less “dark territory,” however, which BC Rail operated in, service failures must be detected by track inspection or train crews. If they are not detected, they are found by a train. The sudden, high-energy nature of a broken rail derailment usually leads to significant costs in vehicle and lading damage, repairs and train delay.

In this case, the required track inspection hadn't been done. A review of a recent ultrasonic inspection showed defect indications at the spacing where the rail had broken up. The defect indications had been cleared by the operator, however, due to surface conditions. It's disappointing when this happens, but it isn’t a unique occurrence in the heavy-haul business. Still, in this case, the rail break likely would have been found if the required track inspection had been done.

The existing rail had a history of TD problems and was approaching rail-wear limits. Grinding had been skipped the previous summer because the rail was scheduled for change-out. The new rail that had been scheduled the previous fall for the curve where the derailment occurred was sitting on the side of the grade underneath the snow and the wrecked cars.

Canada has temperature extremes, but they’re not much different from those in the Dakotas, the mountain country and the U.S. Midwest. When the cold weather came, it came in a hurry dropping by 50 degrees F in a couple of days. This was the second broken rail derailment between Christmas and New Year's that year. The first one was 200 miles north and had been a rail that shattered out of a Flash-butt (FB) weld. There were eight other broken rails that surfaced over a period of three or four days and they were all in the west rail. We found a seriously out-of-round wheel on the west side of a locomotive that had passed north just before all the trouble.

What could have prevented the wreck? A better question is: What will prevent the next one? Firing the roadmaster for a derailment won’t prevent the next derailment; it just deprives your department of needed experience. In this incident, a number of things could have been done differently to prevent the incident. There were failures in program maintenance, rail testing frequencies/reliability, track inspection compliance, the scheduling of capital work as it related to rail wear limits, defective wheel removal, etc. We weren't managing our risks and we weren't managing the wheel/rail interface as a system. When a system is weak, changing out the field personnel won't change the inevitability of another derailment.

Risk Management
Derailments are system failures — a combination of operating, mechanical and track. Management must probe to understand all areas that contributed to the failure in order to commit the appropriate resources required to make a correction. The practice of assigning responsibility to a single cause code, and the cost to a single department works against system analysis; there is no motive to probe for underlying causes, and other departments will not step up to identify and accept responsibility for their part of the problem.

Risk-management on railways is a matter of evaluating and balancing severity and frequency. Risks vary with the type of railway. A high-speed passenger route has different risks and issues than a low-speed switching line that goes through a town center — sometimes carrying hazmat. These railways must be managed differently. You can't run a rail inspection car each spring and fall through the territory and say, “I'm done.” You have to analyze the information derived from testing and make the appropriate corrections. This is particularly important on a smaller railway because the loss of service from a major derailment can pose an enterprise risk. Insurance is hard to get, and if you're not servicing your customers, the business goes away permanently.

Derailments pose significant costs/risks to human/environmental safety, vehicle/lading damage, track repairs, train delay, regulatory intervention and corporate reputation. Derailments and near misses must have a thorough fact-finding-based investigation by well trained track/mechanical/operation teams. Derailment outcomes can vary greatly, so it is helpful to employ risk-management to identify system problems. A formal process should be used to identify safety concerns, technical issues and mitigation strategies. The “formal” aspect is the key. It’s important to get all concerned parties together to discuss what happened, to evaluate and classify the risks and develop mitigation strategies. The concerned parties should agree on mitigation process, establish numbers/targets and goals, then monitor the outcomes and trends with Key Performance Indicators (KPI’s), such as the number of broken rails, Undesired Emergency Brake Applications (UDE), number of exceed limit of authority, reports of vandalism, etc. (Note that a derailment count is not a KPI; it is an outcome.)

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