Volpe Center Continues Railroad Tank Car Structural Integrity Research
Rail transportation of hazardous materials in the United States is recognized as the safest method of moving large quantities of chemicals over long distances. Recent statistics show that the rail industry’s safety performance as a whole is improving. In particular, the vast majority of hazardous materials shipped by rail tank car arrive safely and without incident. In general, the railroads have an outstanding record in moving shipments of hazardous materials safely.
The continued safe transport of hazardous materials is a key concern of the Federal Railroad Administration (FRA). The Volpe Center provides technical support to the FRA’s Office of Research and Development in safety matters regarding the transportation of hazardous materials by railroad tank cars. Research is conducted to support FRA/industry efforts in resolving problems related to metal fatigue and fracture in the current rail tank car fleet, the structural behavior of rail tank cars under potential collision and derailment scenarios, and improving the standards and procedures for future rail car designs.
Railroad tank cars are designed to carry liquefied loads, petroleum products, liquid chemicals, and gasses. FRA and industry are working together to ensure railroad tank car safety. The Volpe Center’s work on safety enhancements supports this effort. This modern tank car is owned by Union Tank Car Company.
Since November 2006, the Volpe Center (for FRA), Dow Chemical Company, Union Pacific Railroad, and the Union Tank Car Company have been collaborating on a high-priority, joint government/industry effort—the Next-Generation Rail Tank Car (NGRTC) Project—to design a rail tank car that will meet or exceed performance requirements while improving safety and security. This includes full-scale impact tests to evaluate the crashworthiness of rail tank cars under accident-loading conditions. The results from the tests will be used to support a Notice for Proposed Rulemaking (NPRM) developed by the Pipeline and Hazardous Materials Safety Administration (PHMSA) and FRA in the creation of the new regulations. The results from the tests will also be used by the NGRTC Project team to develop new tank car designs. FRA signed a Memorandum of Cooperation in January 2007 with the sponsors of the NGRTC Project, to share research information.
On April 26, 2007, a full-scale shell-impact test was conducted on a rail tank car donated by Dow at the Transportation Technology Center (TTC) in Pueblo, Colorado. In this context, shell impact means that the rail tank car is impacted at the side by another rail car. The test was conducted at an impact speed of 14 miles per hour, and resulted in a 9-inch-deep dent. On July 11, another full-scale shell impact test on a railroad tank car designed to carry chlorine was successfully completed at the TTC. This second test resulted in rupture of the tank car shell.
Detailed data will be analyzed by FRA, Volpe Center staff, and contractors, not only to improve tank cars but also to verify and validate analysis tools under development for the project. With the assistance of this ongoing research, FRA, in conjunction with PHMSA, is working to develop new hazardous material tank car safety standards. The target date for a prototype next-generation tank car is April 2008, with the first cars entering service in 2010.
The Volpe Center team was led by Dr. David Jeong and included Mr. Michael Carolan, Ms. Karina Jacobsen, Mr. Jeffrey Gordon, Mr. Mathew Lyons, Mr. Philip Mallon, Dr. Benjamin Perlman, Ms. Michelle Priante, Mr. Brandon Talamini, Ms. Yim Tang, and Mr. David Tyrell, all of the Structures and Dynamics Division, and Dr. Hailing Yu of CASE, LLC, a Volpe Center contractor.