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Overview of Investigation to Understand Progression of Concrete Tie Conditions in High Speed Applications Jeff Henderson Project Engineer. Prepared for the International Concrete Crosstie and Fastening System Symposium June 2012. Project Team. FRA Office of Research and Development
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Overview of Investigation to Understand Progression of Concrete Tie Conditions in High Speed Applications Jeff Henderson Project Engineer Prepared for the International Concrete Crosstie and Fastening System Symposium June 2012
Project Team • FRA Office of Research and Development • AMTRAK • ENSCO Funded under BAA-2010-1 Sponsored by the Federal Railroad Administration FRA OR&D
Research Objectives Develop a better understanding of the progression of defects in concrete ties over time Advance the use of machine vision technology in concrete tie inspection Improve concrete tie inspection practices for high-speed applications
Focus of Study Determine progression rate of cracks in concrete crossties • Consider a statistically significant sample size (~250,000 ties) • Employ three measurement surveys spanning 1.5 years Enlargement
Motivation for Study Intended Broader Impact More efficient inspection intervals Improved maintenance planning and budgeting Improved safety and net operating efficiency • Hairline cracks ultimately result in tie failures upon reaching the rail seat
Main Technical Objective • Better understand the progression from “A” to “B” B A • Tie Failure • Hairline End Crack
High-level Approach • Assess progression of tie condition at discrete states • Combine results to paint a more continuous picture • Late • Early • Mid
Methodology Crack progression assessed “virtually” rather than “live” Machine vision will be used to help locate cracks Crack measurements will be made manually Test Equipment Track Bed Imaging System Rail Side View Imaging System Implementation Plan Overview Track Bed Imaging Rail Side View Imaging
Test Zone 1 • High Street to Atwells • Start/End MP: 143 – 184 • Tie Installation Dates • Brand new • 1978-1979 San-Vel • 1993-1994 Rocla • Traffic: Passenger & Freight • Passenger tonnage: 4.7 to 4.9 MGT • Freight tonnage: 0.1 to 1.5 MGT • Track Miles: 82 miles
Test Zone 2 • Hebronvilleto Mansfield • Start/End MP: 193 – 204 • Tie Installation Date: 1979 San-Vel • Traffic: Passenger & Freight • Passenger tonnage: 4.7 to 4.9 MGT • Freight tonnage: 0.6 to 0.8 MGT • Track Miles: 22 miles
Technical Challenges Challenge 1: Locating hairline cracks in a set of ~250,000 concrete ties • Challenge 2: Precisely aligning ties between consecutive runs • “Enlarge the needle” • “Get your ducks ties in a row”
Main objective of project: To better understand the progression of cracks in concrete ties Final report to discuss: Improved concrete tie inspection practices and intervals Approaches for improving the reliability of concrete tie inspections Approaches for improving tie inspection efficiency Approaches for reducing concrete tie inspection cost Summary
Acknowledgements FRA Office of Research and Development: • Mr. Hugh Thompson, FRA COTR • Amtrak • Mr. Joe Smak • Mr. Michael Trosino • Mr. Steven Sawadisavi Thank you