Track geometry cars no longer plain: Sophisticated data-collection systems permit gathering information, even at high speeds, to detect trouble spots and help plan m/w programs

Railway Track and Structures, Dec, 2001 by Tom Judge

He continued: "Even with fully networked computer systems on the car, the days of on-board data processing and paper strip charts are numbered. Today, geometry data are being collected from the geometry vehicle with wireless networks. Data and reports are distributed on CD-ROM or via the Internet before the vehicle is back from the run. GPS and data correlation provide an absolute location reference. All of these factors combine to reduce the workload of operator/technician on the vehicle."

ZETA-TECH: New approach

All modern track geometry cars measure the basic track geometry parameters and compare them to predefined threshold levels based on either safety or maintenance limits. However, a new approach being taken by ZETA-TECH Associates, Inc., under the sponsorship of the U.S. Department of Transportation, Federal Railroad Administration, is looking at the broader picture. ZETA-TECH is currently developing a real-time vehicle-track interaction assessment tool that virtually runs a series of conventional railway vehicles (freight and/or passenger) over the track as it is being inspected and looks for adverse dynamic behavior under a full range of vehicle speeds.

In this way, the geometry car is not simply looking at one location and one parameter (e.g. gauge) but rather is looking at the total combination of all track geometry parameters that is reflective of each piece of track. It can thus identify and flag potential derailment sites or locations that generate excessively high dynamic force levels/adverse dynamic responses and indicate what is the safe speed limit beyond which certain classes of cars should not operate over that site.

The result is an intelligent software package, within the geometry car's computer system, that can identify locations producing unsafe vehicle performance directly in real time and provide the railroad with an immediate defect report (and on-track painted defect) that will help them maintain a safe track structure.