Wheel/rail interface: a systems approach; a computerized system can be used to determine the condition of both track and rolling stock and when appropriate maintenance should be carried out

Railway Track and Structures, Dec, 2002 by Dr. Willem Ebersohn, Michael Roney, Eric Magel, Fred Prahl

To provide a systems approach to achieving and maintaining a healthy wheel/rail interface, Amtrak and The National Research Council of Canada's Center for Surface Transportation Technology are developing a concept for a computerized Wheel Rail Interface Management System that can be used by all railroad departments, including management, to determine the condition of both track and rolling stock, and to determine when appropriate maintenance should be carried out.

The objective of such a system is to promote a cross-functional approach to continuous improvement in both asset life and service levels. The system will be designed to accept synchronized input data streams related to the track and the vehicles and will display planning and scheduling information that will allow maintenance personnel from both the vehicle and track side to jointly optimize the performance of their assets.

The basic philosophy is to maintain a single integrated data management and analysis system that will allow all management, engineering and mechanical levels access to the information they need to efficiently run the railroad. This implies basic asset condition, as well as financial information, for upper management; asset condition, degradation rates and root causes for engineering and mechanical people; and reports detailing specific maintenance actions and schedules for track and vehicle personnel.

The Amtrak/CSTT vision is that the WRIMS system will facilitate condition-based maintenance for both fixed and moving assets. This will ensure that railroad personnel can make the most-cost-effective maintenance decisions to ensure reliable and safe operations.

Organizing track and vehicle maintenance so that the engineering and mechanical disciplines work together to obtain optimum performance from the interaction of the wheels and rails will effectively reduce the cost of maintenance for both, as well as significantly increase the safety and reliability of Amtrak's operations. This is a natural approach because the performance of the vehicle cannot be evaluated without consideration of the track on which it runs, lust as the performance of the track depends on its interaction with the thousands of wheels that pass over it.

A further benefit is that the concept of combining synchronized data flows, frequent data readings, scheduling, as well as deviation from average information, enables maintenance on rails and wheels (bogies) to be serviced on a more predictive basis. This facilitates the move from reactive (normally performed after failure) and preventive (regularly scheduled replacement or inspection) maintenance to anticipatory maintenance, fitting the work into the schedule before failure and concentrating on deviant components before their failure. This will lead to better work plans, less cost, as well as improved safety and customer satisfaction (e.g., fewer on route delays).

How WRIMS would work

The WRIMS user interface would be two graphic viewers, one which presents information about a railroad's fixed infrastructure and a mechanical viewer that would display vehicle information contained in a wheel database. The wheel database would have all information recorded by vehicle number and axle number and will not only drive the vehicle viewer, but could also be linked directly to the mechanical department's work management system.

One major function of the WRIMS system will be to expand and link the fixed infrastructure data now residing within the Amtrak Information Management System with vehicle information to create a maintenance management system for the wheel/rail interface.

Amtrak presently manages fixed infrastructure with the AMM system, which was developed in partnership with Optram, Inc. Any information in Amtrak's sharable, expandable database that is organized by milepost and footage can be displayed in a viewer called the AMMTRACK Viewer, which is driven by the SED database. The function of the AMMTRACK Viewer is to organize maintenance management information by milepost and relate it to an electronic track chart.

The AMMTRACK Viewer can also import data as long as the information is organized by milepost and footage. A screen grab of the AMMTRACK

Viewer is shown above in Figure 1. Clearly visible are the electronic track chart in the first window, the curvature of track 2 in the second window, and the rail profile and wear measurements in windows 3 to 6. Window 7 shows the rail flaws detected and removed on the west rail (date based), window 8 shows gauge measurements, and, finally, the maximum authorized speed is shown in window 9.

Note that in this view, the mileage is increasing from right to left. At milepost 91 plus 4299, the west rail shows a spike in the gauge and head wear. By investigating the measurements and the rail-flaw data, one can see that an unworn plug was welded into a worn section causing an abrupt change in the contact patch of the wheel and rail. Making this type of information available to field personnel can substantially reduce the amount of mismatch and ride quality problems.