Aurora Automated Inspection Capabilities on Concrete Ties and Fastener Systems

Gregory T. Grissom, P.E.Vice President – Engineering

GREX -  Georgetown Rail Equipment Company111 Cooperative Way, Suite 100, Georgetown, TX  78626

grissom@georgetownrail.com

Introduction: Aurora measurement system

Aurora is an automated railroad track inspection system invented in 2003 by Georgetown Rail Equipment Company (GREX), Texas, USA.

Uses machine vision to create a three dimensional view of the track for the purpose of grading wood ties and collecting rail seat deterioration (RSD) measurements on concrete ties.

Collection optimized at 30 mph, collecting 2.5 GB per mile of data

Three US patents granted and several international patents granted or pending

Currently on the 9th maintenance release of the 2nd generation version of the software.

Digital Imagery Concept

Concrete Crosstie Inspection

13,761 Concrete Miles Inspected Approx. 36,329,040 Concrete Crossties Inspected

Industry Need for Automated Inspection of Concrete Ties and Fastener System

• Inspection/diagnostic solutions at or near track speed

• Rail Seat Deterioration (RSD)

• Pad wear

• Cracking

• Missing/broken insulators

• Missing/broken fasteners

• Immediate defect analysis and reporting system to facilitate immediate feedback for appropriate corrective/preventive action

FRA 49 CFR Part 213.234 RequirementsJuly 1, 2012

Automated inspection of track constructed with concrete

crossties

Concrete tie class 3 main track with passenger service, and

Class 4 and 5 main track constructed with concrete crossties.

The automated inspection measurement system shall

produce an exception report containing a systematic listing of

all exceptions to § 213.109(d)(4)

-Deteriorated or abraded at any point under the rail

seat to a depth of 1/2 inch or more;

3/8 to 1/2 rail seat deterioration as an alert

FRA 49 CFR Part 213.234 RequirementsJuly 1, 2012

An accuracy, to within 1/8 of an inch;

A distance-based sampling interval, which shall not exceed five feet

> 40 MGT twice annually (no less than 160 days between inspections)

< 40 MGT once annually

Exceptions must be located and field-verified no later than 48 hrs after automated inspection

Records kept for two years

2012 Aurora Vehicle Enhancements/Improvements

Remote Login and 24-hr On-truck data processing

Truck vs. Truck repeatability within 1/16 better than 95% of the time

Directional repeatability within 1/16 better than 99% of the time (within 1/32 82% of the time)

FRA ruling requires 1/8 accuracy

Concrete tie configuration resolutions:• Along the track resolution:1/12• Horizontal resolution: 1/32• Vertical resolution: better than 1/32

GPS data accuracy within +/- 15 cm depending on satellite availability

Able to detect Ballast or debris covered ties

3D viewer

Aurora Track Inspection Capabilities

Methodology for RSD & Pad Wear Measurement

• Aurora measures the difference in height from the Top Edge of the Rail Base to the Tie Surface.Call this Value “X”

• The combined known thickness of a Standard Pad System & Rail Base edgeCall this value “Y”

• The difference between the values of X & Y results in Aurora’s measurement of the indicated RSD

Rail Seat Deterioration & Pad Wear Measurement

Testing Date: 4/25/2012   

• For each sampled tie, the difference of the recorded RSA measurement captured from opposite side camera / laser system

must be less than the precision level to qualify

  North Rail South Rail

Total Ties in Test Sample

Precision levels of RSA when recorded from opposite side camera / laser

system

Qty. Ties within precision range

% of all sampled ties

within precision

level

Qty. Ties within

precision range

% of all sampled ties

within precision

level

2647

1/8" 0.125" 2647 100% 2647 100% FRA Mandate precision level = 1/8"

Passed

1/16" 0.063" 2609 99% 2623 99%   Aurora's Internal accepted precision

level AQL

Passed

1/32" 0.031" 2163 82% 2300 87%   Passed

Table 1.Evaluating opposite truck side camera/laser measurement performance on common rail side

2012 Aurora Vehicle Enhancements/ ImprovementsIdentifying ineffective tie/fastening systems

Cracked/broken concrete ties-Determines if concrete tie has cracks or breaks-Aurora has ability to see cracks as small as 1/16 inch in width

Worn Pads-Using the RSA measurement for concrete ties, estimates amount of pad wear

Clips/Fasteners-Capable of identifying Safelok 1, E-Clips and Vossloh fasteners, with current development expanding to other fastener types.-Identifying whether the fastener is present, missing, broken or obstructed

Insulators-Identifying whether the insulator is present, missing or not in position

Identifying wood ties interspersed with concrete ties and measuring corresponding lateral and vertical plate cut

Aurora Fastener Component Library

Cracked/broken concrete ties

Configured with less than two fasteners on the same rail except as provided in § 213.127(c).

Identifying wood ties interspersed with concrete ties and measuring corresponding lateral and vertical plate cut.

Proximity to rail joints

Rail Cant Measurements

Aurora measures the difference between the Field & Gage rail edge heights to calculate the degree of Rail Cant

Rail Cant Measurements

Aurora measures the difference between the Field & Gage rail edge heights to calculate the degree of Rail Cant

Aurora measures the Field & Gage rail edge heights every 1/12” along the track to calculate the degree of Rail Cant

Aurora measures the Field & Gage rail edge heights every 1/12” along the track to calculate the degree of Rail Cant

Rail Head

Rail Head

Rail Cant vs. RSD Measurements

GREX has analyzed several hundred miles of rail cant and RSD as measured by Aurora.

Analyses have largely been inconclusive aside from the following:

- Within Aurora data, instances of outward rail cant > 1.5 degrees do not trend with significant RSD measurement

-Aurora’s rail cant measurement does correlate to clusters of missing, poorly seated, and/or defective gage side fasteners

GREX has provided RSD measurements to compare to systems measuring rail cant with higher lateral and vertical track loadings. Results forthcoming.

Variables Impacting Measurements

Aurora vehicles are optimized to operate at 30 mph in both day and night. Aurora does not operate during rain, snow, etc. or when encountering extreme temperatures (below 32 F or above 120 F).

It is recommended that tracks are broomed prior to inspection, but Aurora has functionality to handle partially obstructed ties.

Aurora also reports percentage of a tie that is obstructed and further provides a summary by mile of number of obstructed ties.

Questions