Interface - The Journal of Wheel/Rail Interaction

W/R INTERACTION ON TRANSIT SYSTEMS

Managing Wheel/Rail Interaction on Rail Transit Systems (continued)

Cooperative Programs
Research and experience drawn from North American freight railways is being adapted and applied to passenger and transit railways. James Dwyer, senior transit consultant with STV, Inc., presented an overview of the research tasks carried out under the Transit Cooperative Research Program (TCRP) Project D-7. The TCRP research, which is done in conjunction with the Association of American Railroads and the TTCI, has generated reports that address specific needs of rail transit agencies. Research topics include broken rail detection, wheel/rail friction, flange climb derailment criteria, and wheel/rail profile design and maintenance guidelines, among others.

William Moorhead, principle of TRAMMCO, LLC., reported on a joint effort between the American Public Transit Association (APTA) and the American Railway Engineering and Maintenance-of-Way Association (AREMA) to develop recommended practices for embedded track for rail transit.

“We’re doing this because manuals and design guides relating to ‘best practice’ designs and construction methods are not up to date,” Moorhead said. “As a result, the rail transit industry puts a lot of time, effort and money into projects with disappointing outcomes and future maintenance problems.”

Excessive noise and vibration have long been sources of complaints in the urban rail environment. While a number of methods, such as friction management, and control of wheel/rail profiles are used to mitigate noise and vibration, the use of so-called mass-spring-systems effectively reduces the transmission of vibrations directly at the source. The mass-spring system uses concrete track slabs supported on a resilient interface. Soft steel coil springs in the mass-spring-systems attenuate vibrations and reduce decibel levels. Since the concrete slabs in the system are relatively low depth, they can be used in tunnels, at grade and on elevated tracks, said Hans-Georg Wagner, GERB Schwingungsisolierungen GmbH & Co.’s head of Building and Trackbed Isolation. The system has been shown to effectively reduce decibel levels by 20 dBA or more.

There is no shortage of challenges. But rail transit systems are obtaining a better understanding of what can be done to better manage wheel/rail interaction in the urban environment.

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