JULY 23, 2015
WASHINGTON, DC
As part of its ongoing investigation of the derailment of a crude oil unit train in Casselton, North Dakota, today the National Transportation Safety Board 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 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.
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.
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