Transportation Technology Center Inc. a subsidiary of the Association of AmericanRailroads, is a global leader in heavy haul R&D. TTCI president Roy A Allen provides readers an insight into research that has added significant value to US heavy haul railway operations.
In the 1970s, the Association of American Railroads (AAR) implemented two large cooperative research programs. One, which continues today, was focused on ways to improve the damage resistance of tank cars involved in accidents and, in particular, on how to prevent the most serious causes of failure.
The other was the Track-Train Dynamics Program, with goals to reduce excessive “train action,” improve operating practices, and improve dynamic stability in general. This research effort continued for more than 15 years and played a huge role in improving the safety and efficiency of train operations in the US.
Today, TTCI continues a very vibrant research program, with a major goal of understanding the technical, safety, and economic issues related to track performance for high tonnage freight traffic and heavy axle loads (HAL).
Achieving lower unit costs for each ton carried by the North American railway industry was facilitated by carefully reviewing and studying the effects of 33 (36-ton) and 35-tonne (39-ton) axle loads before the final decision was made to go with 33-tonne (36-ton) axle loads. The net benefits of the 33-tonne (36-ton) axle load operations are estimated at billions of dollars.
The focus of track and structures research has been to mitigate the effects of dynamic loading and lower the stress state of the railway. This was accomplished by the development of fatigue and wearresistant rail steels, elimination of discontinuities in the track, such as flangeway gaps at frogs, optimisation of contact stresses by wheel and rail running surface profile, and smoothing track transitions, such as at bridge approaches.
Currently there are 11 super premium and eight intermediate hardness rail steels going through wearand fatigue performance at the Facility for Accelerated Service Testing (FAST), Pueblo, Colorado.
A recent rail-life post-audit of TTCI’s rail research indicated that rail life increased approximately 12% on tangent track, and from 12% to 69 percent on curved track, depending on degree of track curvature between 1994 and 2008.
The performance of special trackwork through the development of improved design and materials has improved dramatically since HAL research began in 1988. Elimination of unsupported wheels across flangeway gaps has resulted in reduced frog maintenance, fewer speed restrictions, and increased component service lives.
Other research and development, often in conjunction with suppliers, has resulted in:
- New designs of joint bars, joint configurations, and foundations that have more than doubled the life of rail joints in heavy haul service;
- Recent innovations in concrete tie design, which include use of more complex shapes that increase the vertical and lateral “footprints” of the tie to increase track alignment and surface durability.
- Best practice guidelines that continue to reduce the maintenance and repair costs of vintagerailway bridges, including. Science-based inspection methods and advanced fatigue models and analysis tools and high-strength, lightweight materials, such as composites to improve the effectiveness and economics of either strengthening or replacement.
- Improved track inspection procedures, including performance-based track geometry inspection using neural-network based expert systems, rail neutral temperature measurement systems, and improved rail flaw inspection systems.
- Science-based rail grinding methods and friction control systems to extend the life of rail with overa thousand systems deployed in curved-track territory in North America.
Last, but certainly not least, North American railroads and freight car owners are currently using a new process of condition-based freight car maintenance strategies designed to ensure that adverse vehicle conditions are identified and rectified. TTCI has led and continues to lead the development of wayside detector systems currently in use in North America.
Most recently, TTCI has been working on machine-vision based automated vehicle inspection systems.
Data collected from the detectors is stored in the InteRRIS® database, TTCI’s Integrated RailwayRemote Information Service. This database provides users with the capability to make predictive, condition-based maintenance decisions without having to rely solely on visual inspection. InteRRIS® gathers detector data over the Internet and feeds actionable readings to Railinc’s (a subsidiary company of the AAR) Equipment Health Management System (EHMS) for dissemination to railroads and other car owners.
The EHMS uses automated equipment identification data acquired from detector sites to inform the wagon owner to perform the required maintenance and repair of their equipment.
Heavy haul railways around the world provide the safest, most efficient, and environmentally friendly mode of transporting freight. TTCI will continue its role in railway research and innovation by improving asset utilization and productivity; improving safety of rail transportation in rolling stock, track, and train operations; improving power systems to increase fuel efficiency and reduce emissions; and improving methods and tools for better customer service and service reliability.
For more on R&D, including an analaysis of Australian cutting-edge heavy haul research being conducted by Monash University’s Institute of Railway Technology (IRT) and Central Queensland University’s Centre for Railway Engineering (CRE), see the August harcopy edition of Rail Express.