North American freight railroads uniquely combine safety, speed and efficiency in transporting large amounts of freight long distances over land. Prompted by railroad commitments to reduce emissions, and looming stricter in-use locomotive regulations, US freight railroads face the challenge of reducing or eliminating the roughly 3 billion gallons of diesel fuel consumed each year. To achieve this, North American freight railroads are exploring alternative technologies, including modern options for electrification, batteries, hydrogen fuel cells, and renewable biodiesel.
Previous research involving the University of Texas at Austin developed a tool to help railroads evaluate different locomotive alternatives. The Advanced Locomotive Technology and Rail Infrastructure Optimization System (ALTRIOS) is an open-source simulation framework to model and compare the deployment of conventional and alternative energy locomotive technologies on rail corridors subject to realistic multi-train dispatching and locomotive utilization. The model contains detailed train performance and locomotive powertrain models, and yields outputs quantifying railway operations, costs, energy and emissions.
Previous research has focused on ALTRIOS open-source development, with limited application to case study corridors and a focus on mixed consists of diesel-electric and Battery Electric Locomotives. This research seeks to leverage ALTRIOS to compare a larger set of freight rail propulsion technologies and strategies across a broader group of corridors representative of North American mainline operations.
To accomplish this goal, the project team must research and develop an appropriate ALTRIOS powertrain module to represent the characteristics of hydrogen-powered locomotives, either using fuel cells or direct combustion of hydrogen in a prime mover. Additional refinements to the refueling, cost and emissions modules must also be developed to capture hydrogen and locomotive applications involving renewable biodiesel.
After developing these new ALTRIOS modules, existing modules for battery locomotives and ongoing development of modules for intermittent electrification will be leveraged to conduct a series of case studies comparing multiple locomotive technologies across different corridor topology, topography and train operations. It is expected that different technology deployment strategies will prove to be optimal on certain combinations of corridors and train operations.