As part of its ongoing investigation of the 2014 derailment of a crude oil unit train in Casselton, North Dakota, the National Transportation Safety Board (NTSB) has produced a Train Braking Simulation Study, which it placed into the investigation docket. The study was prompted by recent North American crude oil and ethanol train derailments that resulted in the release of large volumes of flammable liquids that endangered persons, property, and the environment.

The results

The study shows that Electronically Controlled Pneumatic (ECP) brake systems out-performed distributed power configurations, which in turn out-performed conventional brake systems. The study provides detailed description and analysis of each rail braking system and the stopping distances they achieved under various circumstances.

“Over the last decade, the NTSB has investigated a number of catastrophic flammable liquid unit train derailments. Our recommendations have called for improved technologies that can reduce or minimize the risk of derailments. Improved braking capabilities are but one part of the equation in making rail transportation safer,” said NTSB Chairman Christopher A. Hart.

What was studied

The NTSB considered emergency and full service brake applications on uniform grade, tangent track with clean, dry rails. The study also evaluated the effect of different net braking ratios, which measure the amount of force applied by the brake shoes against the wheels. While ECP brake systems performed best, increasing the net braking ratio for any brake system substantially improved its stopping performance.

The NTSB study was peer-reviewed by technical representatives from the Federal Railroad Administration, BNSF, TrinityRail, Standard Steel, the Brotherhood of Locomotive Engineers and Trainmen, and Sharma & Associates, Inc.

The NTSB’s investigation of the Casselton, ND accident is ongoing. Analysis of the accident, along with a determination of probable cause, will come later when the investigation is completed.

To read the study, click on the following link: http://go.usa.gov/3Gz6P.