SBIR-STTR Award

There is a growing trend towards the use of Car-Less technology, where a rail-car is not needed to transport road-haul trailers over rail: Trailers operate in the usual manner over highways, drive up to a rail yard and transform to rail-mode with relative ease. In rail mode, many Car-Less units use slightly modified 3-piece, 70-ton freight car trucks. These trucks are not designed for high-speed operation, especially in Bi-Modal service. Consequently, serious truck hunting and rock & roll issues arise, compromising operational safety. The objective of the project is the conceptual development of advanced trucks for Car-Less systems that can be operated on rail at speeds up to 150 mph. The developed concepts will provide the required safety, lateral stability, ride quality, and curving performance required for such operation. The concepts will also offer easy storage of unused parts, brake systems for both modes and the potential for real-time monitoring of truck performance. We will investigate the applicability of various truck configurations, suspension geometries, and wheel profiles for the new concepts. The feasibility of speed-sensitive suspension and active servo-control of suspension will be investigated. Subsequently, the relative feasibility of the different concepts will be evaluated, with emphasis on the safety, practicality and acceptance of the developed systems by the rail industry.

During Phase I of the project, Sharma & Associates, Inc. developed a concept for a high speed freight truck intended for 70-ton, regular freight and bi-modal operation at speeds up to 150 mph. The truck uses a rigid frame and an independent, compliant, primary suspension for its basic architecture. Constant contact side-bearings and yaw dampers were also added to improve dynamic performance. Vehicle dynamics simulations performed as part of Phase I indicate that the concept truck can travel at 150mph prior to the onset of lateral instability (hunting). The concept trucks also performed well in the other Chapter XI test regimes indicating track worthiness at lower speeds. The primary objective of Phase II of the project is to develop the truck concept into a detailed, practical and track-worthy design that can be prototyped and built for successful over-the-road or Chapter XI testing. A secondary objective is to produce prototypes of its key componenets for additional testing/evaluation. As part of this process, we will conduct additional vehicle dynamics analysis to ensure that the truck performs well under a wide range of scenarios including worn conditions. The most practical methods to achieve the desired suspension characteristics will be determined and the necessary details specified. It is expected that the concepts developed will provide the required safety and track worthiness required for high speed operation.