Team Studies Track Components for Shared-Use Rail Lines

As the U.S. continues to develop higher-speed passenger railway networks, CEE researchers within the Rail Transportation and Engineering Center (RailTEC) are exploring how to use the country’s already extensive freight railway systems so they can also accommodate higher-speed passenger trains that operate at speeds of more than 100 miles per hour.

 

As part of a research initiative funded by the U.S. Department of Transportation’s Federal Railroad Administration (FRA), the CEE department is in the midst of a $2.4 million interdisciplinary research project that aims to better understand the unique demands placed on rail infrastructure when subjected to both higher-speed passenger and freight trains, as well as to improve the design of a critical track component, the concrete crosstie and elastic fastening system.  The focus of the work is not true high-speed rail, in which trains travel at more than 150 miles per hour, but rail lines on which trains will travel approximately 80-125 mph. Led by instructor and RailTEC researcher J. Riley Edwards, CEE researchers in transportation, structures, and materials are collaborating on the project.

 

The demands that freight or higher-speed passenger trains alone place on railroads are understood for the most part, but what is not understood is how these different car types stress railroad infrastructure when they share the same rail corridor.  The main objective of the project, Edwards said, is to understand and improve concrete crossties and fastening systems in these shared-use corridors. The timber crossties commonly found on North American railroads do not exhibit critical materials properties to withstand loads typical of these corridors for extended life cycles, said Professor David Lange of the construction materials area. Concrete crossties have three main advantages, Lange said: their higher mass counteracts the train’s loads and inertia, they are very precisely manufactured, and they are more durable.

 

 

 

The first field experiment, led by Lange and RailTEC Research Engineer Marcus Dersch, concluded at the end of July at a testing facility in Pueblo, Colo. The town offers what Edwards calls the premiere North American railway testing facility, the Transportation Technology Center (TTC), featuring many tracks forming concentric circles that allow trains to operate as fast as 160 miles per hour.

 

"The objective of this testing was to put various types of instrumentation on the rail, crossties, and fastening system components, to better understand the loading demands placed on each of those components,” Edwards said.

 

The July tests included testing a passenger train at speeds up to 102 miles per hour and a freight train consisting of three of today’s most common railcar weights at up to 60 miles per hour. While some higher-speed passenger trains in the U.S. attain speeds of 150 miles per hour, there was no need to test for speeds that great in this project, since a shared-use corridor’s higher-speed passenger trains would generally not exceed 110 miles per hour and freight trains would operate at only up to 70 miles per hour, Dersch said.

 

Currently, data from July’s testing is being processed and being passed on to CEE Assistant Professor Bassem Andrawes of the structures group, to validate the 3-D crosstie and fastening system track model his group is currently developing based on full-scale laboratory testing being led by Associate Professor Daniel Kuchma of the structures group.  This model will ultimately be used by engineers to design improved concrete crossties and fastening systems for both freight and passenger rail networks.  Future field testing is planned; with the additional data being used to answer remaining questions regarding the demands on each component.

 

“Advancements in U.S. higher-speed rail could have wide-reaching impact on society,” Andrawes said. “This is the vision that I think everyone is having.”