00962926

Monograph

http://onlinepubs.trb.org...ail/hsr-18Final_Report.pdf

Railroads rely on electric track circuits to perform, among other things, the critical function of broken rail detection. However, track circuitry, which is expensive to maintain, does not detect a substantial percentage of rail breaks in which electrical continuity is maintained. Fiber optic sensing has great potential as a low-cost means of detecting broken rails. This High-Speed Rail (HSR) Innovations Deserving Exploratory Analysis (IDEA) project investigates the feasibility of using coherent optical time-domain reflectometry (C-OTDR) in concert with advanced signal processing techniques and neural networks in buried fiber optic filaments to detect and locate trains and the ballistic event characteristic of rails breaking under stress. An optical transmission through a continuous length of low-loss, telecommunications-grade fiber buried within the right-of-way holds promise for providing an inexpensive, reliable alternative to conventional track circuitry for train presence and broken rail detection. The technology is shown to be sensitive to perturbation in short fiber lengths (50 m), but using low power C-OTDR practices to detect polarization shift in long fiber lengths (200 m) has shown the system to be ineffective due to the accumulation of noise in the fiber.

This HSR-IDEA project was conducted by the Texas Transportation Institute, College Station, Texas. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

HSR-IDEA Project 18

English

45 p.

2003-8

High-Speed Rail IDEA Program Project Final Report

0010-0210

Figures (16)

Automatic train location; Detection and identification; Fiber optics; High speed rail; High speed track; Interference; Neural networks; Position indicators; Signal processing; Technological innovations; Time domain reflectometers

Innovations Deserving Exploratory Analysis (IDEA) (Program)

Broken rail

Operations and Traffic Management; Railroads

TRIS, TRB

Sep 30 2003 12:00AM