MOWIS

GeoTest

Risk Based Track Geometry Test Scheduling

ZETA-TECH’s GeoTest software package is a risk based, track geometry car test scheduling program used to schedule track geometry car tests and related track inspections based on the condition of the track ( number of defects) and the potential for excessive track geometry defects being developed between inspections, the “risk” The approach utilized is based on a risk-based theory for scheduling ultrasonic test frequencies on freight and passenger railroads initially developed by the US Department of Transportation and by ZETA-TECH Associates.

GeoTest uses key track condition and traffic data together with actual defect history on a segment specific basis to determine test frequency (or interval). Input data includes track geometry condition data taken from track geometry cars, annual traffic density (MGT), and other data as required

The basic premise of GeoTest is to evaluate historical defect occurrence, operating conditions, and previous inspection frequencies, to develop an inspection frequency that maintains a defined level of risk. This level of risk, which can be varied by line segment to reflect differences in traffics, is directly related to the actual defect rate and the corresponding number of FRA and RR defined geometry defects. GeoTest’s analysis algorithms focus on critical defect rates and schedule test frequencies so that the incidence of FRA exceptions (and potential derailments) is minimized.

GeoTest evaluates risk on a segment specific basis, taking into account differences in traffics and route importance. GeoTest looks at the engineering behavior of track geometry defects and incorporates the following engineering based parameters in its calculation of geometry car schedules:

· Defect Initiation: how frequent do defects initiate?
· Defect Growth: how quickly does a defect grow from initiation to failure?
· Detection Reliability: how probable is it that a defect of certain size will be found?
The result is a test scheduling software package that optimizes track geometry car testing frequency to reduce the risk of critical track geometry defects and geometry caused derailments.

GeoTest Features:
· Risk based geometry car test scheduling algorithms
· Risk can be adjusted to account for factors such as passenger traffic, hazardous materials, key routes, etc.
· System sensitive to type and reliability of geometry cars used.
· Ability to analyze both critical and priority defects.
· Ability to analyze defects by type(s) and classes.
· Ability to account for seasonal test effects such as “winter” vs. “summer”.
· Schedules test frequency for practical segment lengths (based on test car capabilities).
· Sensitive to traffic type, density (tonnage), and defect history (both critical and priority)
· Schedules can be reviewed annually, semi-annually or quarterly.
· Capable of analyzing large railway networks (broken down into test segments).

GeoTest Benefits:

· Schedules geometry car tests based on actual risk rather than arbitrary time or tonnage parameters.
· Makes use of existing testing equipment and technology.

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