Technical Reports

Conceptual Development Impact Overload Detection Devices for Tank Car Service

  • 01
  • Aug
  • 2007
AUTHOR: Anand Prabhakaran, David C. Brabb, Vinaya Sharma
OFFICE: RPD
REPORT NUMBER: DOT/FRA/ORD-07/16
SUBJECT: Hazardous Materials
KEYWORDS: Tank car, impact draft gear, overload, tank car safety, inspections, impact testing, over-speed impacts
ABSTRACT: The objective of this project was to develop concepts for mechanical and electronic systems that can detect yard or in-train impacts that exceed design load or other reasonable limits on tank cars. The project team developed some mechanical and electronic systems for detecting overload impacts. For the mechanical system, detection of draft gear travel and closeout offered the best chances for success. For electronic systems, this project identified the following methods for overload impact detection: • Measuring a combination of draft gear travel and draft gear velocity • Measuring impact force using piezo-electric film • Using acceleration measurements for overload detection Although the team developed a fairly accurate way to estimate overload impacts through acceleration measurements, the commercially available unit tested did not function well enough to do the same. It is possible that additional development will help the unit perform better. Therefore, it is recommended that this option not be used for electronic overload detection until additional developments are made. It might be possible for the manufacturer of the tested unit to make adjustments in its functionality that might in turn enable the unit to perform better at threshold detection and transmission.

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