Measuring up - automated technologies lead to better railroad tracks

Railway Age, Sept, 2001 by Tom Judge

The automated track geometry systems that m/w forces use today are among the most sophisticated technologies in the railroad industry.

Almost a quarter century ago, railroads began using high-tech tools to record track geometry. Since then, those tools have become far more sophisticated. Over the past 20 years, automated track geometry inspection has gone from being a tool for quality assurance to an essential part of maintenance planning and safety assurance. Traffic densities, train speeds, and heavy axle loads have risen significantly on most Class I's. Larger territories and reduced windows for track inspection and maintenance have helped to move automated track geometry inspection to the front line of m/w.

New technology has been introduced that has improved the reliability, accuracy, and productivity of automated track geometry inspection systems. Twenty years ago, the issues facing automated track inspection were accuracy and reliability. Advancements in sensors, electronics, and computer technology have made these requirements much easier to meet with off-the-shelf technology. Railroads now are focused on getting the most value for the mountains of track inspection data acquired and getting more automated systems in use to enable more frequent coverage of high-density routes. The most significant technical innovations include low-cost wireless data communications, GPS, GIS (geographical information systems-computer based mapping tools), low-cost handheld computers like the Palm Pilot, and video-based track inspection systems.

ENSCO is one of the leaders of the technological revolution in track geometry. Its most recent offerings include:

* DigiSystems: Palm Pilot-based tools for track inspectors that can download exception data from track geometry cars and use GPS coordinates to navigate to the defect-no more looking for paint marks or measuring distances from mileposts. The system includes the complete FRA Track Safety Standards in the Palm Pilot and enables the track inspector to enter notes directly into the computer in the field.

* Remote Ride Quality Monitoring Systems: Low-cost, lowpower sensors and computers combined with improved cellular data communications help pinpoint priority surface, line, and curve problems long before they present a risk. The systems run unattended and provide reports of exceptions via the Internet, fax, or pager to enable prompt follow-up by m/w forces.

* Low-Cost and Remote Track Geometry Measurement Systems: To help railroads cope with the reduction in track time available for track inspection and the limited supply/high cost of full-sized track geometry inspection vehicles, ENSCO will be introducing a cost-reduced, simple to operate and maintain gauge and crosslevel measurement system for hi-rail vehicles. These systems are intended to supplement full-size track geometry car inspections, often conducted only once or twice per year.

* Video-based Inspection Systems (VIS): This system takes a video "slice" of the trackbed every 1/8 of an inch at speeds up to 50 mph. The images are automatically processed to detect such faults as missing rail clips.

* Automated track geometry inspection pushcart: This lightweight, one-operator system measures and records gauge, crosslevel, profile, and alignment at walking speeds. It can be used as a followup or supplement to automated track inspection cars and as a quality assurance tool behind m/w gangs. Holland Company offers a "heavy hi-rail" testing vehicle called TrackSTAR[R]. Built on a dual-axle, 52,000-pound truck format and capable of testing speeds to 30 mph, TrackSTAR is capable of delivering three key track testing systems: Full track geometry measurement with an inertial based non-contact optical measurement system; track strength measurement using loaded split-axle technology with non-destructive 10,000 pound lateral and 15,000-pound vertical loading; and full rail profile measurement using optical laser cameras. TrackSTAR contract testing service is being used by several Class I's for gauge-restraint testing and supplemental geometry and rail-profile testing.

TrackSTAR provides strip-chart and exception reports to following track crews of gauge and geometry exceptions. Rail profile, geometry, and track strength data is delivered in electronic and hard copy format. Statistical tie-exception summary reports are used for planning and comparison purposes. Onboard software systems deliver curve summary evaluation reports. The operating system allows zoom and scrolling features for quick review while testing data is collected.

KLD Labs, Inc., has been developing and integrating track geometry car measurement systems for about 20 years, and provides systems directly to railroads, and suppliers like Plasser American Corp. and ENSCO. The company has integrated a wide variety of systems on track geometry vehicles operating throughout the world, using non-contact measurement technology.

KLD's High Speed Gauge Measurement System uses video cameras and lasers to measure the gauge point. Gauge measurements can be sampled at exactly one-foot intervals at speeds up to 160 mph. Taking this one step further, KLD's High Speed Rail Measurement System combines the gauge measurement system with its ORIAN (Optical Rail Inspection & Analysis) system, a rail profile measurement system that collects detailed profile and wear data. More recently, KLD introduced two new systems geared toward rail transit. These monitor, with video and laser technology, the distance between running rails and guardrails and the lateral and vertical position of third-rail.